git/credential-cache.c
Jeff King 35a71f1402 credential-cache: ignore "connection refused" errors
The credential-cache helper will try to connect to its
daemon over a unix socket. Originally, a failure to do so
was silently ignored, and we would either give up (if
performing a "get" or "erase" operation), or spawn a new
daemon (for a "store" operation).

But since 8ec6c8d, we try to report more errors. We detect a
missing daemon by checking for ENOENT on our connection
attempt.  If the daemon is missing, we continue as before
(giving up or spawning a new daemon). For any other error,
we die and report the problem.

However, checking for ENOENT is not sufficient for a missing
daemon. We might also get ECONNREFUSED if a dead daemon
process left a stale socket. This generally shouldn't
happen, as the daemon cleans up after itself, but the daemon
may not always be given a chance to do so (e.g., power loss,
"kill -9").

The resulting state is annoying not just because the helper
outputs an extra useless message, but because it actually
blocks the helper from spawning a new daemon to replace the
stale socket.

Fix it by checking for ECONNREFUSED.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-01-16 22:15:19 -08:00

124 lines
2.9 KiB
C

#include "cache.h"
#include "credential.h"
#include "string-list.h"
#include "parse-options.h"
#include "unix-socket.h"
#include "run-command.h"
#define FLAG_SPAWN 0x1
#define FLAG_RELAY 0x2
static int send_request(const char *socket, const struct strbuf *out)
{
int got_data = 0;
int fd = unix_stream_connect(socket);
if (fd < 0)
return -1;
if (write_in_full(fd, out->buf, out->len) < 0)
die_errno("unable to write to cache daemon");
shutdown(fd, SHUT_WR);
while (1) {
char in[1024];
int r;
r = read_in_full(fd, in, sizeof(in));
if (r == 0)
break;
if (r < 0)
die_errno("read error from cache daemon");
write_or_die(1, in, r);
got_data = 1;
}
return got_data;
}
static void spawn_daemon(const char *socket)
{
struct child_process daemon;
const char *argv[] = { NULL, NULL, NULL };
char buf[128];
int r;
memset(&daemon, 0, sizeof(daemon));
argv[0] = "git-credential-cache--daemon";
argv[1] = socket;
daemon.argv = argv;
daemon.no_stdin = 1;
daemon.out = -1;
if (start_command(&daemon))
die_errno("unable to start cache daemon");
r = read_in_full(daemon.out, buf, sizeof(buf));
if (r < 0)
die_errno("unable to read result code from cache daemon");
if (r != 3 || memcmp(buf, "ok\n", 3))
die("cache daemon did not start: %.*s", r, buf);
close(daemon.out);
}
static void do_cache(const char *socket, const char *action, int timeout,
int flags)
{
struct strbuf buf = STRBUF_INIT;
strbuf_addf(&buf, "action=%s\n", action);
strbuf_addf(&buf, "timeout=%d\n", timeout);
if (flags & FLAG_RELAY) {
if (strbuf_read(&buf, 0, 0) < 0)
die_errno("unable to relay credential");
}
if (send_request(socket, &buf) < 0) {
if (errno != ENOENT && errno != ECONNREFUSED)
die_errno("unable to connect to cache daemon");
if (flags & FLAG_SPAWN) {
spawn_daemon(socket);
if (send_request(socket, &buf) < 0)
die_errno("unable to connect to cache daemon");
}
}
strbuf_release(&buf);
}
int main(int argc, const char **argv)
{
char *socket_path = NULL;
int timeout = 900;
const char *op;
const char * const usage[] = {
"git credential-cache [options] <action>",
NULL
};
struct option options[] = {
OPT_INTEGER(0, "timeout", &timeout,
"number of seconds to cache credentials"),
OPT_STRING(0, "socket", &socket_path, "path",
"path of cache-daemon socket"),
OPT_END()
};
argc = parse_options(argc, argv, NULL, options, usage, 0);
if (!argc)
usage_with_options(usage, options);
op = argv[0];
if (!socket_path)
socket_path = expand_user_path("~/.git-credential-cache/socket");
if (!socket_path)
die("unable to find a suitable socket path; use --socket");
if (!strcmp(op, "exit"))
do_cache(socket_path, op, timeout, 0);
else if (!strcmp(op, "get") || !strcmp(op, "erase"))
do_cache(socket_path, op, timeout, FLAG_RELAY);
else if (!strcmp(op, "store"))
do_cache(socket_path, op, timeout, FLAG_RELAY|FLAG_SPAWN);
else
; /* ignore unknown operation */
return 0;
}