rebase --root: fix amending root commit messages
[git.git] / credential-cache--daemon.c
blob4dfbc8c9f917a600c0995b7e33927df3fa19453d
1 #include "cache.h"
2 #include "config.h"
3 #include "tempfile.h"
4 #include "credential.h"
5 #include "unix-socket.h"
6 #include "parse-options.h"
8 struct credential_cache_entry {
9 struct credential item;
10 timestamp_t expiration;
12 static struct credential_cache_entry *entries;
13 static int entries_nr;
14 static int entries_alloc;
16 static void cache_credential(struct credential *c, int timeout)
18 struct credential_cache_entry *e;
20 ALLOC_GROW(entries, entries_nr + 1, entries_alloc);
21 e = &entries[entries_nr++];
23 /* take ownership of pointers */
24 memcpy(&e->item, c, sizeof(*c));
25 memset(c, 0, sizeof(*c));
26 e->expiration = time(NULL) + timeout;
29 static struct credential_cache_entry *lookup_credential(const struct credential *c)
31 int i;
32 for (i = 0; i < entries_nr; i++) {
33 struct credential *e = &entries[i].item;
34 if (credential_match(c, e))
35 return &entries[i];
37 return NULL;
40 static void remove_credential(const struct credential *c)
42 struct credential_cache_entry *e;
44 e = lookup_credential(c);
45 if (e)
46 e->expiration = 0;
49 static timestamp_t check_expirations(void)
51 static timestamp_t wait_for_entry_until;
52 int i = 0;
53 timestamp_t now = time(NULL);
54 timestamp_t next = TIME_MAX;
57 * Initially give the client 30 seconds to actually contact us
58 * and store a credential before we decide there's no point in
59 * keeping the daemon around.
61 if (!wait_for_entry_until)
62 wait_for_entry_until = now + 30;
64 while (i < entries_nr) {
65 if (entries[i].expiration <= now) {
66 entries_nr--;
67 credential_clear(&entries[i].item);
68 if (i != entries_nr)
69 memcpy(&entries[i], &entries[entries_nr], sizeof(*entries));
71 * Stick around 30 seconds in case a new credential
72 * shows up (e.g., because we just removed a failed
73 * one, and we will soon get the correct one).
75 wait_for_entry_until = now + 30;
77 else {
78 if (entries[i].expiration < next)
79 next = entries[i].expiration;
80 i++;
84 if (!entries_nr) {
85 if (wait_for_entry_until <= now)
86 return 0;
87 next = wait_for_entry_until;
90 return next - now;
93 static int read_request(FILE *fh, struct credential *c,
94 struct strbuf *action, int *timeout) {
95 static struct strbuf item = STRBUF_INIT;
96 const char *p;
98 strbuf_getline_lf(&item, fh);
99 if (!skip_prefix(item.buf, "action=", &p))
100 return error("client sent bogus action line: %s", item.buf);
101 strbuf_addstr(action, p);
103 strbuf_getline_lf(&item, fh);
104 if (!skip_prefix(item.buf, "timeout=", &p))
105 return error("client sent bogus timeout line: %s", item.buf);
106 *timeout = atoi(p);
108 if (credential_read(c, fh) < 0)
109 return -1;
110 return 0;
113 static void serve_one_client(FILE *in, FILE *out)
115 struct credential c = CREDENTIAL_INIT;
116 struct strbuf action = STRBUF_INIT;
117 int timeout = -1;
119 if (read_request(in, &c, &action, &timeout) < 0)
120 /* ignore error */ ;
121 else if (!strcmp(action.buf, "get")) {
122 struct credential_cache_entry *e = lookup_credential(&c);
123 if (e) {
124 fprintf(out, "username=%s\n", e->item.username);
125 fprintf(out, "password=%s\n", e->item.password);
128 else if (!strcmp(action.buf, "exit")) {
130 * It's important that we clean up our socket first, and then
131 * signal the client only once we have finished the cleanup.
132 * Calling exit() directly does this, because we clean up in
133 * our atexit() handler, and then signal the client when our
134 * process actually ends, which closes the socket and gives
135 * them EOF.
137 exit(0);
139 else if (!strcmp(action.buf, "erase"))
140 remove_credential(&c);
141 else if (!strcmp(action.buf, "store")) {
142 if (timeout < 0)
143 warning("cache client didn't specify a timeout");
144 else if (!c.username || !c.password)
145 warning("cache client gave us a partial credential");
146 else {
147 remove_credential(&c);
148 cache_credential(&c, timeout);
151 else
152 warning("cache client sent unknown action: %s", action.buf);
154 credential_clear(&c);
155 strbuf_release(&action);
158 static int serve_cache_loop(int fd)
160 struct pollfd pfd;
161 timestamp_t wakeup;
163 wakeup = check_expirations();
164 if (!wakeup)
165 return 0;
167 pfd.fd = fd;
168 pfd.events = POLLIN;
169 if (poll(&pfd, 1, 1000 * wakeup) < 0) {
170 if (errno != EINTR)
171 die_errno("poll failed");
172 return 1;
175 if (pfd.revents & POLLIN) {
176 int client, client2;
177 FILE *in, *out;
179 client = accept(fd, NULL, NULL);
180 if (client < 0) {
181 warning_errno("accept failed");
182 return 1;
184 client2 = dup(client);
185 if (client2 < 0) {
186 warning_errno("dup failed");
187 close(client);
188 return 1;
191 in = xfdopen(client, "r");
192 out = xfdopen(client2, "w");
193 serve_one_client(in, out);
194 fclose(in);
195 fclose(out);
197 return 1;
200 static void serve_cache(const char *socket_path, int debug)
202 int fd;
204 fd = unix_stream_listen(socket_path);
205 if (fd < 0)
206 die_errno("unable to bind to '%s'", socket_path);
208 printf("ok\n");
209 fclose(stdout);
210 if (!debug) {
211 if (!freopen("/dev/null", "w", stderr))
212 die_errno("unable to point stderr to /dev/null");
215 while (serve_cache_loop(fd))
216 ; /* nothing */
218 close(fd);
221 static const char permissions_advice[] = N_(
222 "The permissions on your socket directory are too loose; other\n"
223 "users may be able to read your cached credentials. Consider running:\n"
224 "\n"
225 " chmod 0700 %s");
226 static void init_socket_directory(const char *path)
228 struct stat st;
229 char *path_copy = xstrdup(path);
230 char *dir = dirname(path_copy);
232 if (!stat(dir, &st)) {
233 if (st.st_mode & 077)
234 die(_(permissions_advice), dir);
235 } else {
237 * We must be sure to create the directory with the correct mode,
238 * not just chmod it after the fact; otherwise, there is a race
239 * condition in which somebody can chdir to it, sleep, then try to open
240 * our protected socket.
242 if (safe_create_leading_directories_const(dir) < 0)
243 die_errno("unable to create directories for '%s'", dir);
244 if (mkdir(dir, 0700) < 0)
245 die_errno("unable to mkdir '%s'", dir);
248 if (chdir(dir))
250 * We don't actually care what our cwd is; we chdir here just to
251 * be a friendly daemon and avoid tying up our original cwd.
252 * If this fails, it's OK to just continue without that benefit.
256 free(path_copy);
259 int cmd_main(int argc, const char **argv)
261 struct tempfile *socket_file;
262 const char *socket_path;
263 int ignore_sighup = 0;
264 static const char *usage[] = {
265 "git-credential-cache--daemon [opts] <socket_path>",
266 NULL
268 int debug = 0;
269 const struct option options[] = {
270 OPT_BOOL(0, "debug", &debug,
271 N_("print debugging messages to stderr")),
272 OPT_END()
275 git_config_get_bool("credentialcache.ignoresighup", &ignore_sighup);
277 argc = parse_options(argc, argv, NULL, options, usage, 0);
278 socket_path = argv[0];
280 if (!socket_path)
281 usage_with_options(usage, options);
283 if (!is_absolute_path(socket_path))
284 die("socket directory must be an absolute path");
286 init_socket_directory(socket_path);
287 socket_file = register_tempfile(socket_path);
289 if (ignore_sighup)
290 signal(SIGHUP, SIG_IGN);
292 serve_cache(socket_path, debug);
293 delete_tempfile(&socket_file);
295 return 0;