diff options
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
-rw-r--r-- | net/ipv4/ip_sockglue.c | 58 |
1 files changed, 44 insertions, 14 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index ce231780a2b1..3948c86e59ca 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -238,48 +238,68 @@ int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc) but receiver should be enough clever f.e. to forward mtrace requests, sent to multicast group to reach destination designated router. */ -struct ip_ra_chain *ip_ra_chain; -DEFINE_RWLOCK(ip_ra_lock); +struct ip_ra_chain __rcu *ip_ra_chain; +static DEFINE_SPINLOCK(ip_ra_lock); + + +static void ip_ra_destroy_rcu(struct rcu_head *head) +{ + struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu); + + sock_put(ra->saved_sk); + kfree(ra); +} int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)) { - struct ip_ra_chain *ra, *new_ra, **rap; + struct ip_ra_chain *ra, *new_ra; + struct ip_ra_chain __rcu **rap; if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW) return -EINVAL; new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL; - write_lock_bh(&ip_ra_lock); - for (rap = &ip_ra_chain; (ra = *rap) != NULL; rap = &ra->next) { + spin_lock_bh(&ip_ra_lock); + for (rap = &ip_ra_chain; + (ra = rcu_dereference_protected(*rap, + lockdep_is_held(&ip_ra_lock))) != NULL; + rap = &ra->next) { if (ra->sk == sk) { if (on) { - write_unlock_bh(&ip_ra_lock); + spin_unlock_bh(&ip_ra_lock); kfree(new_ra); return -EADDRINUSE; } - *rap = ra->next; - write_unlock_bh(&ip_ra_lock); + /* dont let ip_call_ra_chain() use sk again */ + ra->sk = NULL; + rcu_assign_pointer(*rap, ra->next); + spin_unlock_bh(&ip_ra_lock); if (ra->destructor) ra->destructor(sk); - sock_put(sk); - kfree(ra); + /* + * Delay sock_put(sk) and kfree(ra) after one rcu grace + * period. This guarantee ip_call_ra_chain() dont need + * to mess with socket refcounts. + */ + ra->saved_sk = sk; + call_rcu(&ra->rcu, ip_ra_destroy_rcu); return 0; } } if (new_ra == NULL) { - write_unlock_bh(&ip_ra_lock); + spin_unlock_bh(&ip_ra_lock); return -ENOBUFS; } new_ra->sk = sk; new_ra->destructor = destructor; new_ra->next = ra; - *rap = new_ra; + rcu_assign_pointer(*rap, new_ra); sock_hold(sk); - write_unlock_bh(&ip_ra_lock); + spin_unlock_bh(&ip_ra_lock); return 0; } @@ -449,7 +469,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) | (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) | (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) | - (1<<IP_MINTTL))) || + (1<<IP_MINTTL) | (1<<IP_NODEFRAG))) || optname == IP_MULTICAST_TTL || optname == IP_MULTICAST_ALL || optname == IP_MULTICAST_LOOP || @@ -572,6 +592,13 @@ static int do_ip_setsockopt(struct sock *sk, int level, } inet->hdrincl = val ? 1 : 0; break; + case IP_NODEFRAG: + if (sk->sk_type != SOCK_RAW) { + err = -ENOPROTOOPT; + break; + } + inet->nodefrag = val ? 1 : 0; + break; case IP_MTU_DISCOVER: if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE) goto e_inval; @@ -1106,6 +1133,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, case IP_HDRINCL: val = inet->hdrincl; break; + case IP_NODEFRAG: + val = inet->nodefrag; + break; case IP_MTU_DISCOVER: val = inet->pmtudisc; break; |