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authorPaolo Bonzini2017-03-16 16:29:45 +0100
committerPaolo Bonzini2017-03-19 11:12:12 +0100
commit53fabd4b86e15869e13fb762686d674c64294385 (patch)
tree8ffb29b28fd121ab3d695e6e89cdd3bef9a6df4b /qemu-nbd.c
parentnios2: iic: Convert CPU prop to qom link (diff)
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qemu-ga: obey LISTEN_PID when using systemd socket activation
qemu-ga's socket activation support was not obeying the LISTEN_PID environment variable, which avoids that a process uses a socket-activation file descriptor meant for its parent. Mess can for example ensue if a process forks a children before consuming the socket-activation file descriptor and therefore setting O_CLOEXEC on it. Luckily, qemu-nbd also got socket activation code, and its copy does support LISTEN_PID. Some extra fixups are needed to ensure that the code can be used for both, but that's what this patch does. The main change is to replace get_listen_fds's "consume" argument with the FIRST_SOCKET_ACTIVATION_FD macro from the qemu-nbd code. Cc: "Richard W.M. Jones" <rjones@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'qemu-nbd.c')
-rw-r--r--qemu-nbd.c100
1 files changed, 8 insertions, 92 deletions
diff --git a/qemu-nbd.c b/qemu-nbd.c
index e4fede641e..e080fb7c75 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -28,6 +28,7 @@
#include "qemu/config-file.h"
#include "qemu/bswap.h"
#include "qemu/log.h"
+#include "qemu/systemd.h"
#include "block/snapshot.h"
#include "qapi/util.h"
#include "qapi/qmp/qstring.h"
@@ -474,98 +475,6 @@ static void setup_address_and_port(const char **address, const char **port)
}
}
-#define FIRST_SOCKET_ACTIVATION_FD 3 /* defined by systemd ABI */
-
-#ifndef _WIN32
-/*
- * Check if socket activation was requested via use of the
- * LISTEN_FDS and LISTEN_PID environment variables.
- *
- * Returns 0 if no socket activation, or the number of FDs.
- */
-static unsigned int check_socket_activation(void)
-{
- const char *s;
- unsigned long pid;
- unsigned long nr_fds;
- unsigned int i;
- int fd;
- int err;
-
- s = getenv("LISTEN_PID");
- if (s == NULL) {
- return 0;
- }
- err = qemu_strtoul(s, NULL, 10, &pid);
- if (err) {
- if (verbose) {
- fprintf(stderr, "malformed %s environment variable (ignored)\n",
- "LISTEN_PID");
- }
- return 0;
- }
- if (pid != getpid()) {
- if (verbose) {
- fprintf(stderr, "%s was not for us (ignored)\n",
- "LISTEN_PID");
- }
- return 0;
- }
-
- s = getenv("LISTEN_FDS");
- if (s == NULL) {
- return 0;
- }
- err = qemu_strtoul(s, NULL, 10, &nr_fds);
- if (err) {
- if (verbose) {
- fprintf(stderr, "malformed %s environment variable (ignored)\n",
- "LISTEN_FDS");
- }
- return 0;
- }
- assert(nr_fds <= UINT_MAX);
-
- /* A limitation of current qemu-nbd is that it can only listen on
- * a single socket. When that limitation is lifted, we can change
- * this function to allow LISTEN_FDS > 1, and remove the assertion
- * in the main function below.
- */
- if (nr_fds > 1) {
- error_report("qemu-nbd does not support socket activation with %s > 1",
- "LISTEN_FDS");
- exit(EXIT_FAILURE);
- }
-
- /* So these are not passed to any child processes we might start. */
- unsetenv("LISTEN_FDS");
- unsetenv("LISTEN_PID");
-
- /* So the file descriptors don't leak into child processes. */
- for (i = 0; i < nr_fds; ++i) {
- fd = FIRST_SOCKET_ACTIVATION_FD + i;
- if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
- /* If we cannot set FD_CLOEXEC then it probably means the file
- * descriptor is invalid, so socket activation has gone wrong
- * and we should exit.
- */
- error_report("Socket activation failed: "
- "invalid file descriptor fd = %d: %m",
- fd);
- exit(EXIT_FAILURE);
- }
- }
-
- return (unsigned int) nr_fds;
-}
-
-#else /* !_WIN32 */
-static unsigned int check_socket_activation(void)
-{
- return 0;
-}
-#endif
-
/*
* Check socket parameters compatibility when socket activation is used.
*/
@@ -892,6 +801,13 @@ int main(int argc, char **argv)
error_report("%s", err_msg);
exit(EXIT_FAILURE);
}
+
+ /* qemu-nbd can only listen on a single socket. */
+ if (socket_activation > 1) {
+ error_report("qemu-nbd does not support socket activation with %s > 1",
+ "LISTEN_FDS");
+ exit(EXIT_FAILURE);
+ }
}
if (tlscredsid) {