summaryrefslogtreecommitdiffstats
path: root/include/uapi/linux/bpf.h
Commit message (Collapse)AuthorAgeFilesLines
* bpf: fix uapi bpf_prog_info fields alignmentBaruch Siach2019-07-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0472301a28f6cf53a6bc5783e48a2d0bbff4682f ] Merge commit 1c8c5a9d38f60 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next") undid the fix from commit 36f9814a494 ("bpf: fix uapi hole for 32 bit compat applications") by taking the gpl_compatible 1-bit field definition from commit b85fab0e67b162 ("bpf: Add gpl_compatible flag to struct bpf_prog_info") as is. That breaks architectures with 16-bit alignment like m68k. Add 31-bit pad after gpl_compatible to restore alignment of following fields. Thanks to Dmitry V. Levin his analysis of this bug history. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Song Liu <songliubraving@fb.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bpf: fix unconnected udp hooksDaniel Borkmann2019-07-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 983695fa676568fc0fe5ddd995c7267aabc24632 upstream. Intention of cgroup bind/connect/sendmsg BPF hooks is to act transparently to applications as also stated in original motivation in 7828f20e3779 ("Merge branch 'bpf-cgroup-bind-connect'"). When recently integrating the latter two hooks into Cilium to enable host based load-balancing with Kubernetes, I ran into the issue that pods couldn't start up as DNS got broken. Kubernetes typically sets up DNS as a service and is thus subject to load-balancing. Upon further debugging, it turns out that the cgroupv2 sendmsg BPF hooks API is currently insufficient and thus not usable as-is for standard applications shipped with most distros. To break down the issue we ran into with a simple example: # cat /etc/resolv.conf nameserver 147.75.207.207 nameserver 147.75.207.208 For the purpose of a simple test, we set up above IPs as service IPs and transparently redirect traffic to a different DNS backend server for that node: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 The attached BPF program is basically selecting one of the backends if the service IP/port matches on the cgroup hook. DNS breaks here, because the hooks are not transparent enough to applications which have built-in msg_name address checks: # nslookup 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ;; connection timed out; no servers could be reached # dig 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; connection timed out; no servers could be reached For comparison, if none of the service IPs is used, and we tell nslookup to use 8.8.8.8 directly it works just fine, of course: # nslookup 1.1.1.1 8.8.8.8 1.1.1.1.in-addr.arpa name = one.one.one.one. In order to fix this and thus act more transparent to the application, this needs reverse translation on recvmsg() side. A minimal fix for this API is to add similar recvmsg() hooks behind the BPF cgroups static key such that the program can track state and replace the current sockaddr_in{,6} with the original service IP. From BPF side, this basically tracks the service tuple plus socket cookie in an LRU map where the reverse NAT can then be retrieved via map value as one example. Side-note: the BPF cgroups static key should be converted to a per-hook static key in future. Same example after this fix: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 Lookups work fine now: # nslookup 1.1.1.1 1.1.1.1.in-addr.arpa name = one.one.one.one. Authoritative answers can be found from: # dig 1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 51550 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;1.1.1.1. IN A ;; AUTHORITY SECTION: . 23426 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2019052001 1800 900 604800 86400 ;; Query time: 17 msec ;; SERVER: 147.75.207.207#53(147.75.207.207) ;; WHEN: Tue May 21 12:59:38 UTC 2019 ;; MSG SIZE rcvd: 111 And from an actual packet level it shows that we're using the back end server when talking via 147.75.207.20{7,8} front end: # tcpdump -i any udp [...] 12:59:52.698732 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.698735 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) [...] In order to be flexible and to have same semantics as in sendmsg BPF programs, we only allow return codes in [1,1] range. In the sendmsg case the program is called if msg->msg_name is present which can be the case in both, connected and unconnected UDP. The former only relies on the sockaddr_in{,6} passed via connect(2) if passed msg->msg_name was NULL. Therefore, on recvmsg side, we act in similar way to call into the BPF program whenever a non-NULL msg->msg_name was passed independent of sk->sk_state being TCP_ESTABLISHED or not. Note that for TCP case, the msg->msg_name is ignored in the regular recvmsg path and therefore not relevant. For the case of ip{,v6}_recv_error() paths, picked up via MSG_ERRQUEUE, the hook is not called. This is intentional as it aligns with the same semantics as in case of TCP cgroup BPF hooks right now. This might be better addressed in future through a different bpf_attach_type such that this case can be distinguished from the regular recvmsg paths, for example. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrey Ignatov <rdna@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf: simplify definition of BPF_FIB_LOOKUP related flagsMartynas Pumputis2019-07-031-2/+2
| | | | | | | | | | | | | | | | | | | commit b1d6c15b9d824a58c5415673f374fac19e8eccdf upstream. Previously, the BPF_FIB_LOOKUP_{DIRECT,OUTPUT} flags in the BPF UAPI were defined with the help of BIT macro. This had the following issues: - In order to use any of the flags, a user was required to depend on <linux/bits.h>. - No other flag in bpf.h uses the macro, so it seems that an unwritten convention is to use (1 << (nr)) to define BPF-related flags. Fixes: 87f5fc7e48dd ("bpf: Provide helper to do forwarding lookups in kernel FIB table") Signed-off-by: Martynas Pumputis <m@lambda.lt> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bpf: Introduce bpf_skb_ancestor_cgroup_id helperAndrey Ignatov2018-08-131-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | == Problem description == It's useful to be able to identify cgroup associated with skb in TC so that a policy can be applied to this skb, and existing bpf_skb_cgroup_id helper can help with this. Though in real life cgroup hierarchy and hierarchy to apply a policy to don't map 1:1. It's often the case that there is a container and corresponding cgroup, but there are many more sub-cgroups inside container, e.g. because it's delegated to containerized application to control resources for its subsystems, or to separate application inside container from infra that belongs to containerization system (e.g. sshd). At the same time it may be useful to apply a policy to container as a whole. If multiple containers like this are run on a host (what is often the case) and many of them have sub-cgroups, it may not be possible to apply per-container policy in TC with existing helpers such as bpf_skb_under_cgroup or bpf_skb_cgroup_id: * bpf_skb_cgroup_id will return id of immediate cgroup associated with skb, i.e. if it's a sub-cgroup inside container, it can't be used to identify container's cgroup; * bpf_skb_under_cgroup can work only with one cgroup and doesn't scale, i.e. if there are N containers on a host and a policy has to be applied to M of them (0 <= M <= N), it'd require M calls to bpf_skb_under_cgroup, and, if M changes, it'd require to rebuild & load new BPF program. == Solution == The patch introduces new helper bpf_skb_ancestor_cgroup_id that can be used to get id of cgroup v2 that is an ancestor of cgroup associated with skb at specified level of cgroup hierarchy. That way admin can place all containers on one level of cgroup hierarchy (what is a good practice in general and already used in many configurations) and identify specific cgroup on this level no matter what sub-cgroup skb is associated with. E.g. if there is a cgroup hierarchy: root/ root/container1/ root/container1/app11/ root/container1/app11/sub-app-a/ root/container1/app12/ root/container2/ root/container2/app21/ root/container2/app22/ root/container2/app22/sub-app-b/ , then having skb associated with root/container1/app11/sub-app-a/ it's possible to get ancestor at level 1, what is container1 and apply policy for this container, or apply another policy if it's container2. Policies can be kept e.g. in a hash map where key is a container cgroup id and value is an action. Levels where container cgroups are created are usually known in advance whether cgroup hierarchy inside container may be hard to predict especially in case when its creation is delegated to containerized application. == Implementation details == The helper gets ancestor by walking parents up to specified level. Another option would be to get different kind of "id" from cgroup->ancestor_ids[level] and use it with idr_find() to get struct cgroup for ancestor. But that would require radix lookup what doesn't seem to be better (at least it's not obviously better). Format of return value of the new helper is same as that of bpf_skb_cgroup_id. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORTMartin KaFai Lau2018-08-111-1/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a BPF_PROG_TYPE_SK_REUSEPORT which can select a SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY. Like other non SK_FILTER/CGROUP_SKB program, it requires CAP_SYS_ADMIN. BPF_PROG_TYPE_SK_REUSEPORT introduces "struct sk_reuseport_kern" to store the bpf context instead of using the skb->cb[48]. At the SO_REUSEPORT sk lookup time, it is in the middle of transiting from a lower layer (ipv4/ipv6) to a upper layer (udp/tcp). At this point, it is not always clear where the bpf context can be appended in the skb->cb[48] to avoid saving-and-restoring cb[]. Even putting aside the difference between ipv4-vs-ipv6 and udp-vs-tcp. It is not clear if the lower layer is only ipv4 and ipv6 in the future and will it not touch the cb[] again before transiting to the upper layer. For example, in udp_gro_receive(), it uses the 48 byte NAPI_GRO_CB instead of IP[6]CB and it may still modify the cb[] after calling the udp[46]_lib_lookup_skb(). Because of the above reason, if sk->cb is used for the bpf ctx, saving-and-restoring is needed and likely the whole 48 bytes cb[] has to be saved and restored. Instead of saving, setting and restoring the cb[], this patch opts to create a new "struct sk_reuseport_kern" and setting the needed values in there. The new BPF_PROG_TYPE_SK_REUSEPORT and "struct sk_reuseport_(kern|md)" will serve all ipv4/ipv6 + udp/tcp combinations. There is no protocol specific usage at this point and it is also inline with the current sock_reuseport.c implementation (i.e. no protocol specific requirement). In "struct sk_reuseport_md", this patch exposes data/data_end/len with semantic similar to other existing usages. Together with "bpf_skb_load_bytes()" and "bpf_skb_load_bytes_relative()", the bpf prog can peek anywhere in the skb. The "bind_inany" tells the bpf prog that the reuseport group is bind-ed to a local INANY address which cannot be learned from skb. The new "bind_inany" is added to "struct sock_reuseport" which will be used when running the new "BPF_PROG_TYPE_SK_REUSEPORT" bpf prog in order to avoid repeating the "bind INANY" test on "sk_v6_rcv_saddr/sk->sk_rcv_saddr" every time a bpf prog is run. It can only be properly initialized when a "sk->sk_reuseport" enabled sk is adding to a hashtable (i.e. during "reuseport_alloc()" and "reuseport_add_sock()"). The new "sk_select_reuseport()" is the main helper that the bpf prog will use to select a SO_REUSEPORT sk. It is the only function that can use the new BPF_MAP_TYPE_REUSEPORT_ARRAY. As mentioned in the earlier patch, the validity of a selected sk is checked in run time in "sk_select_reuseport()". Doing the check in verification time is difficult and inflexible (consider the map-in-map use case). The runtime check is to compare the selected sk's reuseport_id with the reuseport_id that we want. This helper will return -EXXX if the selected sk cannot serve the incoming request (e.g. reuseport_id not match). The bpf prog can decide if it wants to do SK_DROP as its discretion. When the bpf prog returns SK_PASS, the kernel will check if a valid sk has been selected (i.e. "reuse_kern->selected_sk != NULL"). If it does , it will use the selected sk. If not, the kernel will select one from "reuse->socks[]" (as before this patch). The SK_DROP and SK_PASS handling logic will be in the next patch. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAYMartin KaFai Lau2018-08-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a new map type BPF_MAP_TYPE_REUSEPORT_SOCKARRAY. To unleash the full potential of a bpf prog, it is essential for the userspace to be capable of directly setting up a bpf map which can then be consumed by the bpf prog to make decision. In this case, decide which SO_REUSEPORT sk to serve the incoming request. By adding BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, the userspace has total control and visibility on where a SO_REUSEPORT sk should be located in a bpf map. The later patch will introduce BPF_PROG_TYPE_SK_REUSEPORT such that the bpf prog can directly select a sk from the bpf map. That will raise the programmability of the bpf prog attached to a reuseport group (a group of sk serving the same IP:PORT). For example, in UDP, the bpf prog can peek into the payload (e.g. through the "data" pointer introduced in the later patch) to learn the application level's connection information and then decide which sk to pick from a bpf map. The userspace can tightly couple the sk's location in a bpf map with the application logic in generating the UDP payload's connection information. This connection info contact/API stays within the userspace. Also, when used with map-in-map, the userspace can switch the old-server-process's inner map to a new-server-process's inner map in one call "bpf_map_update_elem(outer_map, &index, &new_reuseport_array)". The bpf prog will then direct incoming requests to the new process instead of the old process. The old process can finish draining the pending requests (e.g. by "accept()") before closing the old-fds. [Note that deleting a fd from a bpf map does not necessary mean the fd is closed] During map_update_elem(), Only SO_REUSEPORT sk (i.e. which has already been added to a reuse->socks[]) can be used. That means a SO_REUSEPORT sk that is "bind()" for UDP or "bind()+listen()" for TCP. These conditions are ensured in "reuseport_array_update_check()". A SO_REUSEPORT sk can only be added once to a map (i.e. the same sk cannot be added twice even to the same map). SO_REUSEPORT already allows another sk to be created for the same IP:PORT. There is no need to re-create a similar usage in the BPF side. When a SO_REUSEPORT is deleted from the "reuse->socks[]" (e.g. "close()"), it will notify the bpf map to remove it from the map also. It is done through "bpf_sk_reuseport_detach()" and it will only be called if >=1 of the "reuse->sock[]" has ever been added to a bpf map. The map_update()/map_delete() has to be in-sync with the "reuse->socks[]". Hence, the same "reuseport_lock" used by "reuse->socks[]" has to be used here also. Care has been taken to ensure the lock is only acquired when the adding sk passes some strict tests. and freeing the map does not require the reuseport_lock. The reuseport_array will also support lookup from the syscall side. It will return a sock_gen_cookie(). The sock_gen_cookie() is on-demand (i.e. a sk's cookie is not generated until the very first map_lookup_elem()). The lookup cookie is 64bits but it goes against the logical userspace expectation on 32bits sizeof(fd) (and as other fd based bpf maps do also). It may catch user in surprise if we enforce value_size=8 while userspace still pass a 32bits fd during update. Supporting different value_size between lookup and update seems unintuitive also. We also need to consider what if other existing fd based maps want to return 64bits value from syscall's lookup in the future. Hence, reuseport_array supports both value_size 4 and 8, and assuming user will usually use value_size=4. The syscall's lookup will return ENOSPC on value_size=4. It will will only return 64bits value from sock_gen_cookie() when user consciously choose value_size=8 (as a signal that lookup is desired) which then requires a 64bits value in both lookup and update. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: introduce the bpf_get_local_storage() helper functionRoman Gushchin2018-08-031-1/+20
| | | | | | | | | | | | | | | | The bpf_get_local_storage() helper function is used to get a pointer to the bpf local storage from a bpf program. It takes a pointer to a storage map and flags as arguments. Right now it accepts only cgroup storage maps, and flags argument has to be 0. Further it can be extended to support other types of local storage: e.g. thread local storage etc. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: introduce cgroup storage mapsRoman Gushchin2018-08-031-0/+6
| | | | | | | | | | | | | | | | | | | | | This commit introduces BPF_MAP_TYPE_CGROUP_STORAGE maps: a special type of maps which are implementing the cgroup storage. >From the userspace point of view it's almost a generic hash map with the (cgroup inode id, attachment type) pair used as a key. The only difference is that some operations are restricted: 1) a user can't create new entries, 2) a user can't remove existing entries. The lookup from userspace is o(log(n)). Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Support bpf_get_socket_cookie in more prog typesAndrey Ignatov2018-07-311-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | bpf_get_socket_cookie() helper can be used to identify skb that correspond to the same socket. Though socket cookie can be useful in many other use-cases where socket is available in program context. Specifically BPF_PROG_TYPE_CGROUP_SOCK_ADDR and BPF_PROG_TYPE_SOCK_OPS programs can benefit from it so that one of them can augment a value in a map prepared earlier by other program for the same socket. The patch adds support to call bpf_get_socket_cookie() from BPF_PROG_TYPE_CGROUP_SOCK_ADDR and BPF_PROG_TYPE_SOCK_OPS. It doesn't introduce new helpers. Instead it reuses same helper name bpf_get_socket_cookie() but adds support to this helper to accept `struct bpf_sock_addr` and `struct bpf_sock_ops`. Documentation in bpf.h is changed in a way that should not break automatic generation of markdown. Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Add BPF_SOCK_OPS_TCP_LISTEN_CBAndrey Ignatov2018-07-151-0/+3
| | | | | | | | | | | | | | | | | | | Add new TCP-BPF callback that is called on listen(2) right after socket transition to TCP_LISTEN state. It fills the gap for listening sockets in TCP-BPF. For example BPF program can set BPF_SOCK_OPS_STATE_CB_FLAG when socket becomes listening and track later transition from TCP_LISTEN to TCP_CLOSE with BPF_SOCK_OPS_STATE_CB callback. Before there was no way to do it with TCP-BPF and other options were much harder to work with. E.g. socket state tracking can be done with tracepoints (either raw or regular) but they can't be attached to cgroup and their lifetime has to be managed separately. Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix documentation for eBPF helpersQuentin Monnet2018-07-121-4/+2Star
| | | | | | | | | | Minor formatting edits for eBPF helpers documentation, including blank lines removal, fix of item list for return values in bpf_fib_lookup(), and missing prefix on bpf_skb_load_bytes_relative(). Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: Change bpf_fib_lookup to return lookup statusDavid Ahern2018-06-291-5/+23
| | | | | | | | | | | | | | | | | For ACLs implemented using either FIB rules or FIB entries, the BPF program needs the FIB lookup status to be able to drop the packet. Since the bpf_fib_lookup API has not reached a released kernel yet, change the return code to contain an encoding of the FIB lookup result and return the nexthop device index in the params struct. In addition, inform the BPF program of any post FIB lookup reason as to why the packet needs to go up the stack. The fib result for unicast routes must have an egress device, so remove the check that it is non-NULL. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2018-06-051-27/+109
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2018-06-05 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add a new BPF hook for sendmsg similar to existing hooks for bind and connect: "This allows to override source IP (including the case when it's set via cmsg(3)) and destination IP:port for unconnected UDP (slow path). TCP and connected UDP (fast path) are not affected. This makes UDP support complete, that is, connected UDP is handled by connect hooks, unconnected by sendmsg ones.", from Andrey. 2) Rework of the AF_XDP API to allow extending it in future for type writer model if necessary. In this mode a memory window is passed to hardware and multiple frames might be filled into that window instead of just one that is the case in the current fixed frame-size model. With the new changes made this can be supported without having to add a new descriptor format. Also, core bits for the zero-copy support for AF_XDP have been merged as agreed upon, where i40e bits will be routed via Jeff later on. Various improvements to documentation and sample programs included as well, all from Björn and Magnus. 3) Given BPF's flexibility, a new program type has been added to implement infrared decoders. Quote: "The kernel IR decoders support the most widely used IR protocols, but there are many protocols which are not supported. [...] There is a 'long tail' of unsupported IR protocols, for which lircd is need to decode the IR. IR encoding is done in such a way that some simple circuit can decode it; therefore, BPF is ideal. [...] user-space can define a decoder in BPF, attach it to the rc device through the lirc chardev.", from Sean. 4) Several improvements and fixes to BPF core, among others, dumping map and prog IDs into fdinfo which is a straight forward way to correlate BPF objects used by applications, removing an indirect call and therefore retpoline in all map lookup/update/delete calls by invoking the callback directly for 64 bit archs, adding a new bpf_skb_cgroup_id() BPF helper for tc BPF programs to have an efficient way of looking up cgroup v2 id for policy or other use cases. Fixes to make sure we zero tunnel/xfrm state that hasn't been filled, to allow context access wrt pt_regs in 32 bit archs for tracing, and last but not least various test cases for fixes that landed in bpf earlier, from Daniel. 5) Get rid of the ndo_xdp_flush API and extend the ndo_xdp_xmit with a XDP_XMIT_FLUSH flag instead which allows to avoid one indirect call as flushing is now merged directly into ndo_xdp_xmit(), from Jesper. 6) Add a new bpf_get_current_cgroup_id() helper that can be used in tracing to retrieve the cgroup id from the current process in order to allow for e.g. aggregation of container-level events, from Yonghong. 7) Two follow-up fixes for BTF to reject invalid input values and related to that also two test cases for BPF kselftests, from Martin. 8) Various API improvements to the bpf_fib_lookup() helper, that is, dropping MPLS bits which are not fully hashed out yet, rejecting invalid helper flags, returning error for unsupported address families as well as renaming flowlabel to flowinfo, from David. 9) Various fixes and improvements to sockmap BPF kselftests in particular in proper error detection and data verification, from Prashant. 10) Two arm32 BPF JIT improvements. One is to fix imm range check with regards to whether immediate fits into 24 bits, and a naming cleanup to get functions related to rsh handling consistent to those handling lsh, from Wang. 11) Two compile warning fixes in BPF, one for BTF and a false positive to silent gcc in stack_map_get_build_id_offset(), from Arnd. 12) Add missing seg6.h header into tools include infrastructure in order to fix compilation of BPF kselftests, from Mathieu. 13) Several formatting cleanups in the BPF UAPI helper description that also fix an error during rst2man compilation, from Quentin. 14) Hide an unused variable in sk_msg_convert_ctx_access() when IPv6 is not built into the kernel, from Yue. 15) Remove a useless double assignment in dev_map_enqueue(), from Colin. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: flowlabel in bpf_fib_lookup should be flowinfoDavid Ahern2018-06-041-1/+1
| | | | | | | | | | | | | | | | | | | | As Michal noted the flow struct takes both the flow label and priority. Update the bpf_fib_lookup API to note that it is flowinfo and not just the flow label. Cc: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: implement bpf_get_current_cgroup_id() helperYonghong Song2018-06-041-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf has been used extensively for tracing. For example, bcc contains an almost full set of bpf-based tools to trace kernel and user functions/events. Most tracing tools are currently either filtered based on pid or system-wide. Containers have been used quite extensively in industry and cgroup is often used together to provide resource isolation and protection. Several processes may run inside the same container. It is often desirable to get container-level tracing results as well, e.g. syscall count, function count, I/O activity, etc. This patch implements a new helper, bpf_get_current_cgroup_id(), which will return cgroup id based on the cgroup within which the current task is running. The later patch will provide an example to show that userspace can get the same cgroup id so it could configure a filter or policy in the bpf program based on task cgroup id. The helper is currently implemented for tracing. It can be added to other program types as well when needed. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: make sure to clear unused fields in tunnel/xfrm state fetchDaniel Borkmann2018-06-031-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the remaining bits are not filled in struct bpf_tunnel_key resp. struct bpf_xfrm_state and originate from uninitialized stack space, we should make sure to clear them before handing control back to the program. Also add a padding element to struct bpf_xfrm_state for future use similar as we have in struct bpf_tunnel_key and clear it as well. struct bpf_xfrm_state { __u32 reqid; /* 0 4 */ __u32 spi; /* 4 4 */ __u16 family; /* 8 2 */ /* XXX 2 bytes hole, try to pack */ union { __u32 remote_ipv4; /* 4 */ __u32 remote_ipv6[4]; /* 16 */ }; /* 12 16 */ /* size: 28, cachelines: 1, members: 4 */ /* sum members: 26, holes: 1, sum holes: 2 */ /* last cacheline: 28 bytes */ }; Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add bpf_skb_cgroup_id helperDaniel Borkmann2018-06-031-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new bpf_skb_cgroup_id() helper that allows to retrieve the cgroup id from the skb's socket. This is useful in particular to enable bpf_get_cgroup_classid()-like behavior for cgroup v1 in cgroup v2 by allowing ID based matching on egress. This can in particular be used in combination with applying policy e.g. from map lookups, and also complements the older bpf_skb_under_cgroup() interface. In user space the cgroup id for a given path can be retrieved through the f_handle as demonstrated in [0] recently. [0] https://lkml.org/lkml/2018/5/22/1190 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * media: rc: introduce BPF_PROG_LIRC_MODE2Sean Young2018-05-301-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | Add support for BPF_PROG_LIRC_MODE2. This type of BPF program can call rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report that the last key should be repeated. The bpf program can be attached to using the bpf(BPF_PROG_ATTACH) syscall; the target_fd must be the /dev/lircN device. Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: Drop mpls from bpf_fib_lookupDavid Ahern2018-05-291-13/+13
| | | | | | | | | | | | | | | | | | | | MPLS support will not be submitted this dev cycle, but in working on it I do see a few changes are needed to the API. For now, drop mpls from the API. Since the fields in question are unions, the mpls fields can be added back later without affecting the uapi. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: clean up eBPF helpers documentationQuentin Monnet2018-05-291-11/+10Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are minor edits for the eBPF helpers documentation in include/uapi/linux/bpf.h. The main fix consists in removing "BPF_FIB_LOOKUP_", because it ends with a non-escaped underscore that gets interpreted by rst2man and produces the following message in the resulting manual page: DOCUTILS SYSTEM MESSAGES System Message: ERROR/3 (/tmp/bpf-helpers.rst:, line 1514) Unknown target name: "bpf_fib_lookup". Other edits consist in: - Improving formatting for flag values for "bpf_fib_lookup()" helper. - Emphasising a parameter name in description of the return value for "bpf_get_stack()" helper. - Removing unnecessary blank lines between "Description" and "Return" sections for the few helpers that would use it, for consistency. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: Hooks for sys_sendmsgAndrey Ignatov2018-05-281-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In addition to already existing BPF hooks for sys_bind and sys_connect, the patch provides new hooks for sys_sendmsg. It leverages existing BPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that provides access to socket itlself (properties like family, type, protocol) and user-passed `struct sockaddr *` so that BPF program can override destination IP and port for system calls such as sendto(2) or sendmsg(2) and/or assign source IP to the socket. The hooks are implemented as two new attach types: `BPF_CGROUP_UDP4_SENDMSG` and `BPF_CGROUP_UDP6_SENDMSG` for UDPv4 and UDPv6 correspondingly. UDPv4 and UDPv6 separate attach types for same reason as sys_bind and sys_connect hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound. The difference with already existing hooks is sys_sendmsg are implemented only for unconnected UDP. For TCP it doesn't make sense to change user-provided `struct sockaddr *` at sendto(2)/sendmsg(2) time since socket either was already connected and has source/destination set or wasn't connected and call to sendto(2)/sendmsg(2) would lead to ENOTCONN anyway. Connected UDP is already handled by sys_connect hooks that can override source/destination at connect time and use fast-path later, i.e. these hooks don't affect UDP fast-path. Rewriting source IP is implemented differently than that in sys_connect hooks. When sys_sendmsg is used with unconnected UDP it doesn't work to just bind socket to desired local IP address since source IP can be set on per-packet basis by using ancillary data (cmsg(3)). So no matter if socket is bound or not, source IP has to be rewritten on every call to sys_sendmsg. To do so two new fields are added to UAPI `struct bpf_sock_addr`; * `msg_src_ip4` to set source IPv4 for UDPv4; * `msg_src_ip6` to set source IPv6 for UDPv6. Signed-off-by: Andrey Ignatov <rdna@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-06-031-0/+1
|\ \ | |/ |/| | | | | | | | | | | Filling in the padding slot in the bpf structure as a bug fix in 'ne' overlapped with actually using that padding area for something in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: fix uapi hole for 32 bit compat applicationsDaniel Borkmann2018-06-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 64 bit, we have a 4 byte hole between ifindex and netns_dev in the case of struct bpf_map_info but also struct bpf_prog_info. In net-next commit b85fab0e67b ("bpf: Add gpl_compatible flag to struct bpf_prog_info") added a bitfield into it to expose some flags related to programs. Thus, add an unnamed __u32 bitfield for both so that alignment keeps the same in both 32 and 64 bit cases, and can be naturally extended from there as in b85fab0e67b. Before: # file test.o test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped # pahole test.o struct bpf_map_info { __u32 type; /* 0 4 */ __u32 id; /* 4 4 */ __u32 key_size; /* 8 4 */ __u32 value_size; /* 12 4 */ __u32 max_entries; /* 16 4 */ __u32 map_flags; /* 20 4 */ char name[16]; /* 24 16 */ __u32 ifindex; /* 40 4 */ __u64 netns_dev; /* 44 8 */ __u64 netns_ino; /* 52 8 */ /* size: 64, cachelines: 1, members: 10 */ /* padding: 4 */ }; After (same as on 64 bit): # file test.o test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped # pahole test.o struct bpf_map_info { __u32 type; /* 0 4 */ __u32 id; /* 4 4 */ __u32 key_size; /* 8 4 */ __u32 value_size; /* 12 4 */ __u32 max_entries; /* 16 4 */ __u32 map_flags; /* 20 4 */ char name[16]; /* 24 16 */ __u32 ifindex; /* 40 4 */ /* XXX 4 bytes hole, try to pack */ __u64 netns_dev; /* 48 8 */ __u64 netns_ino; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ /* size: 64, cachelines: 1, members: 10 */ /* sum members: 60, holes: 1, sum holes: 4 */ }; Reported-by: Dmitry V. Levin <ldv@altlinux.org> Reported-by: Eugene Syromiatnikov <esyr@redhat.com> Fixes: 52775b33bb507 ("bpf: offload: report device information about offloaded maps") Fixes: 675fc275a3a2d ("bpf: offload: report device information for offloaded programs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: introduce bpf subcommand BPF_TASK_FD_QUERYYonghong Song2018-05-251-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, suppose a userspace application has loaded a bpf program and attached it to a tracepoint/kprobe/uprobe, and a bpf introspection tool, e.g., bpftool, wants to show which bpf program is attached to which tracepoint/kprobe/uprobe. Such attachment information will be really useful to understand the overall bpf deployment in the system. There is a name field (16 bytes) for each program, which could be used to encode the attachment point. There are some drawbacks for this approaches. First, bpftool user (e.g., an admin) may not really understand the association between the name and the attachment point. Second, if one program is attached to multiple places, encoding a proper name which can imply all these attachments becomes difficult. This patch introduces a new bpf subcommand BPF_TASK_FD_QUERY. Given a pid and fd, if the <pid, fd> is associated with a tracepoint/kprobe/uprobe perf event, BPF_TASK_FD_QUERY will return . prog_id . tracepoint name, or . k[ret]probe funcname + offset or kernel addr, or . u[ret]probe filename + offset to the userspace. The user can use "bpftool prog" to find more information about bpf program itself with prog_id. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | ipv6: sr: Add seg6local action End.BPFMathieu Xhonneux2018-05-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the End.BPF action to the LWT seg6local infrastructure. This action works like any other seg6local End action, meaning that an IPv6 header with SRH is needed, whose DA has to be equal to the SID of the action. It will also advance the SRH to the next segment, the BPF program does not have to take care of this. Since the BPF program may not be a source of instability in the kernel, it is important to ensure that the integrity of the packet is maintained before yielding it back to the IPv6 layer. The hook hence keeps track if the SRH has been altered through the helpers, and re-validates its content if needed with seg6_validate_srh. The state kept for validation is stored in a per-CPU buffer. The BPF program is not allowed to directly write into the packet, and only some fields of the SRH can be altered through the helper bpf_lwt_seg6_store_bytes. Performances profiling has shown that the SRH re-validation does not induce a significant overhead. If the altered SRH is deemed as invalid, the packet is dropped. This validation is also done before executing any action through bpf_lwt_seg6_action, and will not be performed again if the SRH is not modified after calling the action. The BPF program may return 3 types of return codes: - BPF_OK: the End.BPF action will look up the next destination through seg6_lookup_nexthop. - BPF_REDIRECT: if an action has been executed through the bpf_lwt_seg6_action helper, the BPF program should return this value, as the skb's destination is already set and the default lookup should not be performed. - BPF_DROP : the packet will be dropped. Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: Add IPv6 Segment Routing helpersMathieu Xhonneux2018-05-241-1/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The BPF seg6local hook should be powerful enough to enable users to implement most of the use-cases one could think of. After some thinking, we figured out that the following actions should be possible on a SRv6 packet, requiring 3 specific helpers : - bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH - bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH (to add/delete TLVs) - bpf_lwt_seg6_action: Apply some SRv6 network programming actions (specifically End.X, End.T, End.B6 and End.B6.Encap) The specifications of these helpers are provided in the patch (see include/uapi/linux/bpf.h). The non-sensitive fields of the SRH are the following : flags, tag and TLVs. The other fields can not be modified, to maintain the SRH integrity. Flags, tag and TLVs can easily be modified as their validity can be checked afterwards via seg6_validate_srh. It is not allowed to modify the segments directly. If one wants to add segments on the path, he should stack a new SRH using the End.B6 action via bpf_lwt_seg6_action. Growing, shrinking or editing TLVs via the helpers will flag the SRH as invalid, and it will have to be re-validated before re-entering the IPv6 layer. This flag is stored in a per-CPU buffer, along with the current header length in bytes. Storing the SRH len in bytes in the control block is mandatory when using bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes boundary). When adding/deleting TLVs within the BPF program, the SRH may temporary be in an invalid state where its length cannot be rounded to 8 bytes without remainder, hence the need to store the length in bytes separately. The caller of the BPF program can then ensure that the SRH's final length is valid using this value. Again, a final SRH modified by a BPF program which doesn’t respect the 8-bytes boundary will be discarded as it will be considered as invalid. Finally, a fourth helper is provided, bpf_lwt_push_encap, which is available from the LWT BPF IN hook, but not from the seg6local BPF one. This helper allows to encapsulate a Segment Routing Header (either with a new outer IPv6 header, or by inlining it directly in the existing IPv6 header) into a non-SRv6 packet. This helper is required if we want to offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet, as the BPF seg6local hook only works on traffic already containing a SRH. This is the BPF equivalent of the seg6 LWT infrastructure, which achieves the same purpose but with a static SRH per route. These helpers require CONFIG_IPV6=y (and not =m). Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Acked-by: David Lebrun <dlebrun@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: get JITed image lengths of functions via syscallSandipan Das2018-05-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds new two new fields to struct bpf_prog_info. For multi-function programs, these fields can be used to pass a list of the JITed image lengths of each function for a given program to userspace using the bpf system call with the BPF_OBJ_GET_INFO_BY_FD command. This can be used by userspace applications like bpftool to split up the contiguous JITed dump, also obtained via the system call, into more relatable chunks corresponding to each function. Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: get kernel symbol addresses via syscallSandipan Das2018-05-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds new two new fields to struct bpf_prog_info. For multi-function programs, these fields can be used to pass a list of kernel symbol addresses for all functions in a given program to userspace using the bpf system call with the BPF_OBJ_GET_INFO_BY_FD command. When bpf_jit_kallsyms is enabled, we can get the address of the corresponding kernel symbol for a callee function and resolve the symbol's name. The address is determined by adding the value of the call instruction's imm field to __bpf_call_base. This offset gets assigned to the imm field by the verifier. For some architectures, such as powerpc64, the imm field is not large enough to hold this offset. We resolve this by: [1] Assigning the subprog id to the imm field of a call instruction in the verifier instead of the offset of the callee's symbol's address from __bpf_call_base. [2] Determining the address of a callee's corresponding symbol by using the imm field as an index for the list of kernel symbol addresses now available from the program info. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: btf: Rename btf_key_id and btf_value_id in bpf_map_infoMartin KaFai Lau2018-05-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In "struct bpf_map_info", the name "btf_id", "btf_key_id" and "btf_value_id" could cause confusion because the "id" of "btf_id" means the BPF obj id given to the BTF object while "btf_key_id" and "btf_value_id" means the BTF type id within that BTF object. To make it clear, btf_key_id and btf_value_id are renamed to btf_key_type_id and btf_value_type_id. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: allow sk_msg programs to read sock fieldsJohn Fastabend2018-05-181-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently sk_msg programs only have access to the raw data. However, it is often useful when building policies to have the policies specific to the socket endpoint. This allows using the socket tuple as input into filters, etc. This patch adds ctx access to the sock fields. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: sockmap, add hash map supportJohn Fastabend2018-05-151-2/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sockmap is currently backed by an array and enforces keys to be four bytes. This works well for many use cases and was originally modeled after devmap which also uses four bytes keys. However, this has become limiting in larger use cases where a hash would be more appropriate. For example users may want to use the 5-tuple of the socket as the lookup key. To support this add hash support. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: Provide helper to do forwarding lookups in kernel FIB tableDavid Ahern2018-05-111-1/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a helper for doing a FIB and neighbor lookup in the kernel tables from an XDP program. The helper provides a fastpath for forwarding packets. If the packet is a local delivery or for any reason is not a simple lookup and forward, the packet continues up the stack. If it is to be forwarded, the forwarding can be done directly if the neighbor is already known. If the neighbor does not exist, the first few packets go up the stack for neighbor resolution. Once resolved, the xdp program provides the fast path. On successful lookup the nexthop dmac, current device smac and egress device index are returned. The API supports IPv4, IPv6 and MPLS protocols, but only IPv4 and IPv6 are implemented in this patch. The API includes layer 4 parameters if the XDP program chooses to do deep packet inspection to allow compare against ACLs implemented as FIB rules. Header rewrite is left to the XDP program. The lookup takes 2 flags: - BPF_FIB_LOOKUP_DIRECT to do a lookup that bypasses FIB rules and goes straight to the table associated with the device (expert setting for those looking to maximize throughput) - BPF_FIB_LOOKUP_OUTPUT to do a lookup from the egress perspective. Default is an ingress lookup. Initial performance numbers collected by Jesper, forwarded packets/sec: Full stack XDP FIB lookup XDP Direct lookup IPv4 1,947,969 7,074,156 7,415,333 IPv6 1,728,000 6,165,504 7,262,720 These number are single CPU core forwarding on a Broadwell E5-1650 v4 @ 3.60GHz. Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: btf: Add struct bpf_btf_infoMartin KaFai Lau2018-05-091-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During BPF_OBJ_GET_INFO_BY_FD on a btf_fd, the current bpf_attr's info.info is directly filled with the BTF binary data. It is not extensible. In this case, we want to add BTF ID. This patch adds "struct bpf_btf_info" which has the BTF ID as one of its member. The BTF binary data itself is exposed through the "btf" and "btf_size" members. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: btf: Introduce BTF IDMartin KaFai Lau2018-05-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch gives an ID to each loaded BTF. The ID is allocated by the idr like the existing prog-id and map-id. The bpf_put(map->btf) is moved to __bpf_map_put() so that the userspace can stop seeing the BTF ID ASAP when the last BTF refcnt is gone. It also makes BTF accessible from userspace through the 1. new BPF_BTF_GET_FD_BY_ID command. It is limited to CAP_SYS_ADMIN which is inline with the BPF_BTF_LOAD cmd and the existing BPF_[MAP|PROG]_GET_FD_BY_ID cmd. 2. new btf_id (and btf_key_id + btf_value_id) in "struct bpf_map_info" Once the BTF ID handler is accessible from userspace, freeing a BTF object has to go through a rcu period. The BPF_BTF_GET_FD_BY_ID cmd can then be done under a rcu_read_lock() instead of taking spin_lock. [Note: A similar rcu usage can be done to the existing bpf_prog_get_fd_by_id() in a follow up patch] When processing the BPF_BTF_GET_FD_BY_ID cmd, refcount_inc_not_zero() is needed because the BTF object could be already in the rcu dead row . btf_get() is removed since its usage is currently limited to btf.c alone. refcount_inc() is used directly instead. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add skb_load_bytes_relative helperDaniel Borkmann2018-05-041-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a small BPF helper similar to bpf_skb_load_bytes() that is able to load relative to mac/net header offset from the skb's linear data. Compared to bpf_skb_load_bytes(), it takes a fifth argument namely start_header, which is either BPF_HDR_START_MAC or BPF_HDR_START_NET. This allows for a more flexible alternative compared to LD_ABS/LD_IND with negative offset. It's enabled for tc BPF programs as well as sock filter program types where it's mainly useful in reuseport programs to ease access to lower header data. Reference: https://lists.iovisor.org/pipermail/iovisor-dev/2017-March/000698.html Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAPBjörn Töpel2018-05-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The xskmap is yet another BPF map, very much inspired by dev/cpu/sockmap, and is a holder of AF_XDP sockets. A user application adds AF_XDP sockets into the map, and by using the bpf_redirect_map helper, an XDP program can redirect XDP frames to an AF_XDP socket. Note that a socket that is bound to certain ifindex/queue index will *only* accept XDP frames from that netdev/queue index. If an XDP program tries to redirect from a netdev/queue index other than what the socket is bound to, the frame will not be received on the socket. A socket can reside in multiple maps. v3: Fixed race and simplified code. v2: Removed one indirection in map lookup. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: fix formatting for bpf_get_stack() helper docQuentin Monnet2018-04-301-27/+27
| | | | | | | | | | | | | | | | | | | | Fix formatting (indent) for bpf_get_stack() helper documentation, so that the doc is rendered correctly with the Python script. Fixes: c195651e565a ("bpf: add bpf_get_stack helper") Cc: Yonghong Song <yhs@fb.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: fix formatting for bpf_perf_event_read() helper docQuentin Monnet2018-04-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Some edits brought to the last iteration of BPF helper functions documentation introduced an error with RST formatting. As a result, most of one paragraph is rendered in bold text when only the name of a helper should be. Fix it, and fix formatting of another function name in the same paragraph. Fixes: c6b5fb8690fa ("bpf: add documentation for eBPF helpers (42-50)") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: Fix helpers ctx struct types in uapi docAndrey Ignatov2018-04-291-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Helpers may operate on two types of ctx structures: user visible ones (e.g. `struct bpf_sock_ops`) when used in user programs, and kernel ones (e.g. `struct bpf_sock_ops_kern`) in kernel implementation. UAPI documentation must refer to only user visible structures. The patch replaces references to `_kern` structures in BPF helpers description by corresponding user visible structures. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: add bpf_get_stack helperYonghong Song2018-04-291-2/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, stackmap and bpf_get_stackid helper are provided for bpf program to get the stack trace. This approach has a limitation though. If two stack traces have the same hash, only one will get stored in the stackmap table, so some stack traces are missing from user perspective. This patch implements a new helper, bpf_get_stack, will send stack traces directly to bpf program. The bpf program is able to see all stack traces, and then can do in-kernel processing or send stack traces to user space through shared map or bpf_perf_event_output. Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: add documentation for eBPF helpers (65-66)Quentin Monnet2018-04-271-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions: Helper from Nikita: - bpf_xdp_adjust_tail() Helper from Eyal: - bpf_skb_get_xfrm_state() v4: - New patch (helpers did not exist yet for previous versions). Cc: Nikita V. Shirokov <tehnerd@tehnerd.com> Cc: Eyal Birger <eyal.birger@gmail.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (58-64)Quentin Monnet2018-04-271-0/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions, all written by John: - bpf_redirect_map() - bpf_sk_redirect_map() - bpf_sock_map_update() - bpf_msg_redirect_map() - bpf_msg_apply_bytes() - bpf_msg_cork_bytes() - bpf_msg_pull_data() v4: - bpf_redirect_map(): Fix typos: "XDP_ABORT" changed to "XDP_ABORTED", "his" to "this". Also add a paragraph on performance improvement over bpf_redirect() helper. v3: - bpf_sk_redirect_map(): Improve description of BPF_F_INGRESS flag. - bpf_msg_redirect_map(): Improve description of BPF_F_INGRESS flag. - bpf_redirect_map(): Fix note on CPU redirection, not fully implemented for generic XDP but supported on native XDP. - bpf_msg_pull_data(): Clarify comment about invalidated verifier checks. Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (51-57)Quentin Monnet2018-04-271-0/+180
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions: Helpers from Lawrence: - bpf_setsockopt() - bpf_getsockopt() - bpf_sock_ops_cb_flags_set() Helpers from Yonghong: - bpf_perf_event_read_value() - bpf_perf_prog_read_value() Helper from Josef: - bpf_override_return() Helper from Andrey: - bpf_bind() v4: - bpf_perf_event_read_value(): State that this helper should be preferred over bpf_perf_event_read(). v3: - bpf_perf_event_read_value(): Fix time of selection for perf event type in description. Remove occurences of "cores" to avoid confusion with "CPU". - bpf_bind(): Remove last paragraph of description, which was off topic. Cc: Lawrence Brakmo <brakmo@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Andrey Ignatov <rdna@fb.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Yonghong Song <yhs@fb.com> [for bpf_perf_event_read_value(), bpf_perf_prog_read_value()] Acked-by: Andrey Ignatov <rdna@fb.com> [for bpf_bind()] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (42-50)Quentin Monnet2018-04-271-0/+172
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions: Helper from Kaixu: - bpf_perf_event_read() Helpers from Martin: - bpf_skb_under_cgroup() - bpf_xdp_adjust_head() Helpers from Sargun: - bpf_probe_write_user() - bpf_current_task_under_cgroup() Helper from Thomas: - bpf_skb_change_head() Helper from Gianluca: - bpf_probe_read_str() Helpers from Chenbo: - bpf_get_socket_cookie() - bpf_get_socket_uid() v4: - bpf_perf_event_read(): State that bpf_perf_event_read_value() should be preferred over this helper. - bpf_skb_change_head(): Clarify comment about invalidated verifier checks. - bpf_xdp_adjust_head(): Clarify comment about invalidated verifier checks. - bpf_probe_write_user(): Add that dst must be a valid user space address. - bpf_get_socket_cookie(): Improve description by making clearer that the cockie belongs to the socket, and state that it remains stable for the life of the socket. v3: - bpf_perf_event_read(): Fix time of selection for perf event type in description. Remove occurences of "cores" to avoid confusion with "CPU". Cc: Martin KaFai Lau <kafai@fb.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Thomas Graf <tgraf@suug.ch> Cc: Gianluca Borello <g.borello@gmail.com> Cc: Chenbo Feng <fengc@google.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> [for bpf_skb_under_cgroup(), bpf_xdp_adjust_head()] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (33-41)Quentin Monnet2018-04-271-0/+164
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions, all written by Daniel: - bpf_get_hash_recalc() - bpf_skb_change_tail() - bpf_skb_pull_data() - bpf_csum_update() - bpf_set_hash_invalid() - bpf_get_numa_node_id() - bpf_set_hash() - bpf_skb_adjust_room() - bpf_xdp_adjust_meta() v4: - bpf_skb_change_tail(): Clarify comment about invalidated verifier checks. - bpf_skb_pull_data(): Clarify the motivation for using this helper or bpf_skb_load_bytes(), on non-linear buffers. Fix RST formatting for *skb*. Clarify comment about invalidated verifier checks. - bpf_csum_update(): Fix description of checksum (entire packet, not IP checksum). Fix a typo: "header" instead of "helper". - bpf_set_hash_invalid(): Mention bpf_get_hash_recalc(). - bpf_get_numa_node_id(): State that the helper is not restricted to programs attached to sockets. - bpf_skb_adjust_room(): Clarify comment about invalidated verifier checks. - bpf_xdp_adjust_meta(): Clarify comment about invalidated verifier checks. Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (23-32)Quentin Monnet2018-04-271-0/+197
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions, all written by Daniel: - bpf_get_prandom_u32() - bpf_get_smp_processor_id() - bpf_get_cgroup_classid() - bpf_get_route_realm() - bpf_skb_load_bytes() - bpf_csum_diff() - bpf_skb_get_tunnel_opt() - bpf_skb_set_tunnel_opt() - bpf_skb_change_proto() - bpf_skb_change_type() v4: - bpf_get_prandom_u32(): Warn that the prng is not cryptographically secure. - bpf_get_smp_processor_id(): Fix a typo (case). - bpf_get_cgroup_classid(): Clarify description. Add notes on the helper being limited to cgroup v1, and to egress path. - bpf_get_route_realm(): Add comparison with bpf_get_cgroup_classid(). Add a note about usage with TC and advantage of clsact. Fix a typo in return value ("sdb" instead of "skb"). - bpf_skb_load_bytes(): Make explicit loading large data loads it to the eBPF stack. - bpf_csum_diff(): Add a note on seed that can be cascaded. Link to bpf_l3|l4_csum_replace(). - bpf_skb_get_tunnel_opt(): Add a note about usage with "collect metadata" mode, and example of this with Geneve. - bpf_skb_set_tunnel_opt(): Add a link to bpf_skb_get_tunnel_opt() description. - bpf_skb_change_proto(): Mention that the main use case is NAT64. Clarify comment about invalidated verifier checks. v3: - bpf_get_prandom_u32(): Fix helper name :(. Add description, including a note on the internal random state. - bpf_get_smp_processor_id(): Add description, including a note on the processor id remaining stable during program run. - bpf_get_cgroup_classid(): State that CONFIG_CGROUP_NET_CLASSID is required to use the helper. Add a reference to related documentation. State that placing a task in net_cls controller disables cgroup-bpf. - bpf_get_route_realm(): State that CONFIG_CGROUP_NET_CLASSID is required to use this helper. - bpf_skb_load_bytes(): Fix comment on current use cases for the helper. Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (12-22)Quentin Monnet2018-04-271-0/+254
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions, all written by Alexei: - bpf_get_current_pid_tgid() - bpf_get_current_uid_gid() - bpf_get_current_comm() - bpf_skb_vlan_push() - bpf_skb_vlan_pop() - bpf_skb_get_tunnel_key() - bpf_skb_set_tunnel_key() - bpf_redirect() - bpf_perf_event_output() - bpf_get_stackid() - bpf_get_current_task() v4: - bpf_redirect(): Fix typo: "XDP_ABORT" changed to "XDP_ABORTED". Add note on bpf_redirect_map() providing better performance. Replace "Save for" with "Except for". - bpf_skb_vlan_push(): Clarify comment about invalidated verifier checks. - bpf_skb_vlan_pop(): Clarify comment about invalidated verifier checks. - bpf_skb_get_tunnel_key(): Add notes on tunnel_id, "collect metadata" mode, and example tunneling protocols with which it can be used. - bpf_skb_set_tunnel_key(): Add a reference to the description of bpf_skb_get_tunnel_key(). - bpf_perf_event_output(): Specify that, and for what purpose, the helper can be used with programs attached to TC and XDP. v3: - bpf_skb_get_tunnel_key(): Change and improve description and example. - bpf_redirect(): Improve description of BPF_F_INGRESS flag. - bpf_perf_event_output(): Fix first sentence of description. Delete wrong statement on context being evaluated as a struct pt_reg. Remove the long yet incomplete example. - bpf_get_stackid(): Add a note about PERF_MAX_STACK_DEPTH being configurable. Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add documentation for eBPF helpers (01-11)Quentin Monnet2018-04-271-0/+230
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add documentation for eBPF helper functions to bpf.h user header file. This documentation can be parsed with the Python script provided in another commit of the patch series, in order to provide a RST document that can later be converted into a man page. The objective is to make the documentation easily understandable and accessible to all eBPF developers, including beginners. This patch contains descriptions for the following helper functions, all written by Alexei: - bpf_map_lookup_elem() - bpf_map_update_elem() - bpf_map_delete_elem() - bpf_probe_read() - bpf_ktime_get_ns() - bpf_trace_printk() - bpf_skb_store_bytes() - bpf_l3_csum_replace() - bpf_l4_csum_replace() - bpf_tail_call() - bpf_clone_redirect() v4: - bpf_map_lookup_elem(): Add "const" qualifier for key. - bpf_map_update_elem(): Add "const" qualifier for key and value. - bpf_map_lookup_elem(): Add "const" qualifier for key. - bpf_skb_store_bytes(): Clarify comment about invalidated verifier checks. - bpf_l3_csum_replace(): Mention L3 instead of just IP, and add a note about bpf_csum_diff(). - bpf_l4_csum_replace(): Mention L4 instead of just TCP/UDP, and add a note about bpf_csum_diff(). - bpf_tail_call(): Bring minor edits to description. - bpf_clone_redirect(): Add a note about the relation with bpf_redirect(). Also clarify comment about invalidated verifier checks. v3: - bpf_map_lookup_elem(): Fix description of restrictions for flags related to the existence of the entry. - bpf_trace_printk(): State that trace_pipe can be configured. Fix return value in case an unknown format specifier is met. Add a note on kernel log notice when the helper is used. Edit example. - bpf_tail_call(): Improve comment on stack inheritance. - bpf_clone_redirect(): Improve description of BPF_F_INGRESS flag. Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: add script and prepare bpf.h for new helpers documentationQuentin Monnet2018-04-271-406/+16Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove previous "overview" of eBPF helpers from user bpf.h header. Replace it by a comment explaining how to process the new documentation (to come in following patches) with a Python script to produce RST, then man page documentation. Also add the aforementioned Python script under scripts/. It is used to process include/uapi/linux/bpf.h and to extract helper descriptions, to turn it into a RST document that can further be processed with rst2man to produce a man page. The script takes one "--filename <path/to/file>" option. If the script is launched from scripts/ in the kernel root directory, it should be able to find the location of the header to parse, and "--filename <path/to/file>" is then optional. If it cannot find the file, then the option becomes mandatory. RST-formatted documentation is printed to standard output. Typical workflow for producing the final man page would be: $ ./scripts/bpf_helpers_doc.py \ --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7 $ man /tmp/bpf-helpers.7 Note that the tool kernel-doc cannot be used to document eBPF helpers, whose signatures are not available directly in the header files (pre-processor directives are used to produce them at the beginning of the compilation process). v4: - Also remove overviews for newly added bpf_xdp_adjust_tail() and bpf_skb_get_xfrm_state(). - Remove vague statement about what helpers are restricted to GPL programs in "LICENSE" section for man page footer. - Replace license boilerplate with SPDX tag for Python script. v3: - Change license for man page. - Remove "for safety reasons" from man page header text. - Change "packets metadata" to "packets" in man page header text. - Move and fix comment on helpers introducing no overhead. - Remove "NOTES" section from man page footer. - Add "LICENSE" section to man page footer. - Edit description of file include/uapi/linux/bpf.h in man page footer. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: Add gpl_compatible flag to struct bpf_prog_infoJiri Olsa2018-04-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding gpl_compatible flag to struct bpf_prog_info so it can be dumped via bpf_prog_get_info_by_fd and displayed via bpftool progs dump. Alexei noticed 4-byte hole in struct bpf_prog_info, so we put the u32 flags field in there, and we can keep adding bit fields in there without breaking user space. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-14 16:48:49 +0200