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git/unix-socket.c
René Scharfe 2869b3e5da unix-socket: remove stale socket before calling chdir()
unix_stream_listen() is given a path.  It calls unix_sockaddr_init(),
which in turn can call chdir().  After that a relative path doesn't
mean the same as before.  Any use of the original path should thus
happen before that call.  For that reason, unlink the given path
(to get rid of a possibly existing stale socket) right at the
beginning of the function.

Noticed-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-21 09:38:07 -07:00

124 lines
2.4 KiB
C

#include "cache.h"
#include "unix-socket.h"
static int unix_stream_socket(void)
{
int fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
die_errno("unable to create socket");
return fd;
}
static int chdir_len(const char *orig, int len)
{
char *path = xmemdupz(orig, len);
int r = chdir(path);
free(path);
return r;
}
struct unix_sockaddr_context {
char orig_dir[PATH_MAX];
};
static void unix_sockaddr_cleanup(struct unix_sockaddr_context *ctx)
{
if (!ctx->orig_dir[0])
return;
/*
* If we fail, we can't just return an error, since we have
* moved the cwd of the whole process, which could confuse calling
* code. We are better off to just die.
*/
if (chdir(ctx->orig_dir) < 0)
die("unable to restore original working directory");
}
static int unix_sockaddr_init(struct sockaddr_un *sa, const char *path,
struct unix_sockaddr_context *ctx)
{
int size = strlen(path) + 1;
ctx->orig_dir[0] = '\0';
if (size > sizeof(sa->sun_path)) {
const char *slash = find_last_dir_sep(path);
const char *dir;
if (!slash) {
errno = ENAMETOOLONG;
return -1;
}
dir = path;
path = slash + 1;
size = strlen(path) + 1;
if (size > sizeof(sa->sun_path)) {
errno = ENAMETOOLONG;
return -1;
}
if (!getcwd(ctx->orig_dir, sizeof(ctx->orig_dir))) {
errno = ENAMETOOLONG;
return -1;
}
if (chdir_len(dir, slash - dir) < 0)
return -1;
}
memset(sa, 0, sizeof(*sa));
sa->sun_family = AF_UNIX;
memcpy(sa->sun_path, path, size);
return 0;
}
int unix_stream_connect(const char *path)
{
int fd, saved_errno;
struct sockaddr_un sa;
struct unix_sockaddr_context ctx;
if (unix_sockaddr_init(&sa, path, &ctx) < 0)
return -1;
fd = unix_stream_socket();
if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
goto fail;
unix_sockaddr_cleanup(&ctx);
return fd;
fail:
saved_errno = errno;
unix_sockaddr_cleanup(&ctx);
close(fd);
errno = saved_errno;
return -1;
}
int unix_stream_listen(const char *path)
{
int fd, saved_errno;
struct sockaddr_un sa;
struct unix_sockaddr_context ctx;
unlink(path);
if (unix_sockaddr_init(&sa, path, &ctx) < 0)
return -1;
fd = unix_stream_socket();
if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
goto fail;
if (listen(fd, 5) < 0)
goto fail;
unix_sockaddr_cleanup(&ctx);
return fd;
fail:
saved_errno = errno;
unix_sockaddr_cleanup(&ctx);
close(fd);
errno = saved_errno;
return -1;
}