pickaxe: assert that we must have a needle under -G or -S
[git/debian.git] / builtin / credential-cache--daemon.c
blob4c6c89ab0de2eb3dbc2785033249e853aea32f16
1 #include "builtin.h"
2 #include "parse-options.h"
4 #ifndef NO_UNIX_SOCKETS
6 #include "config.h"
7 #include "tempfile.h"
8 #include "credential.h"
9 #include "unix-socket.h"
11 struct credential_cache_entry {
12 struct credential item;
13 timestamp_t expiration;
15 static struct credential_cache_entry *entries;
16 static int entries_nr;
17 static int entries_alloc;
19 static void cache_credential(struct credential *c, int timeout)
21 struct credential_cache_entry *e;
23 ALLOC_GROW(entries, entries_nr + 1, entries_alloc);
24 e = &entries[entries_nr++];
26 /* take ownership of pointers */
27 memcpy(&e->item, c, sizeof(*c));
28 memset(c, 0, sizeof(*c));
29 e->expiration = time(NULL) + timeout;
32 static struct credential_cache_entry *lookup_credential(const struct credential *c)
34 int i;
35 for (i = 0; i < entries_nr; i++) {
36 struct credential *e = &entries[i].item;
37 if (credential_match(c, e))
38 return &entries[i];
40 return NULL;
43 static void remove_credential(const struct credential *c)
45 struct credential_cache_entry *e;
47 e = lookup_credential(c);
48 if (e)
49 e->expiration = 0;
52 static timestamp_t check_expirations(void)
54 static timestamp_t wait_for_entry_until;
55 int i = 0;
56 timestamp_t now = time(NULL);
57 timestamp_t next = TIME_MAX;
60 * Initially give the client 30 seconds to actually contact us
61 * and store a credential before we decide there's no point in
62 * keeping the daemon around.
64 if (!wait_for_entry_until)
65 wait_for_entry_until = now + 30;
67 while (i < entries_nr) {
68 if (entries[i].expiration <= now) {
69 entries_nr--;
70 credential_clear(&entries[i].item);
71 if (i != entries_nr)
72 memcpy(&entries[i], &entries[entries_nr], sizeof(*entries));
74 * Stick around 30 seconds in case a new credential
75 * shows up (e.g., because we just removed a failed
76 * one, and we will soon get the correct one).
78 wait_for_entry_until = now + 30;
80 else {
81 if (entries[i].expiration < next)
82 next = entries[i].expiration;
83 i++;
87 if (!entries_nr) {
88 if (wait_for_entry_until <= now)
89 return 0;
90 next = wait_for_entry_until;
93 return next - now;
96 static int read_request(FILE *fh, struct credential *c,
97 struct strbuf *action, int *timeout)
99 static struct strbuf item = STRBUF_INIT;
100 const char *p;
102 strbuf_getline_lf(&item, fh);
103 if (!skip_prefix(item.buf, "action=", &p))
104 return error("client sent bogus action line: %s", item.buf);
105 strbuf_addstr(action, p);
107 strbuf_getline_lf(&item, fh);
108 if (!skip_prefix(item.buf, "timeout=", &p))
109 return error("client sent bogus timeout line: %s", item.buf);
110 *timeout = atoi(p);
112 if (credential_read(c, fh) < 0)
113 return -1;
114 return 0;
117 static void serve_one_client(FILE *in, FILE *out)
119 struct credential c = CREDENTIAL_INIT;
120 struct strbuf action = STRBUF_INIT;
121 int timeout = -1;
123 if (read_request(in, &c, &action, &timeout) < 0)
124 /* ignore error */ ;
125 else if (!strcmp(action.buf, "get")) {
126 struct credential_cache_entry *e = lookup_credential(&c);
127 if (e) {
128 fprintf(out, "username=%s\n", e->item.username);
129 fprintf(out, "password=%s\n", e->item.password);
132 else if (!strcmp(action.buf, "exit")) {
134 * It's important that we clean up our socket first, and then
135 * signal the client only once we have finished the cleanup.
136 * Calling exit() directly does this, because we clean up in
137 * our atexit() handler, and then signal the client when our
138 * process actually ends, which closes the socket and gives
139 * them EOF.
141 exit(0);
143 else if (!strcmp(action.buf, "erase"))
144 remove_credential(&c);
145 else if (!strcmp(action.buf, "store")) {
146 if (timeout < 0)
147 warning("cache client didn't specify a timeout");
148 else if (!c.username || !c.password)
149 warning("cache client gave us a partial credential");
150 else {
151 remove_credential(&c);
152 cache_credential(&c, timeout);
155 else
156 warning("cache client sent unknown action: %s", action.buf);
158 credential_clear(&c);
159 strbuf_release(&action);
162 static int serve_cache_loop(int fd)
164 struct pollfd pfd;
165 timestamp_t wakeup;
167 wakeup = check_expirations();
168 if (!wakeup)
169 return 0;
171 pfd.fd = fd;
172 pfd.events = POLLIN;
173 if (poll(&pfd, 1, 1000 * wakeup) < 0) {
174 if (errno != EINTR)
175 die_errno("poll failed");
176 return 1;
179 if (pfd.revents & POLLIN) {
180 int client, client2;
181 FILE *in, *out;
183 client = accept(fd, NULL, NULL);
184 if (client < 0) {
185 warning_errno("accept failed");
186 return 1;
188 client2 = dup(client);
189 if (client2 < 0) {
190 warning_errno("dup failed");
191 close(client);
192 return 1;
195 in = xfdopen(client, "r");
196 out = xfdopen(client2, "w");
197 serve_one_client(in, out);
198 fclose(in);
199 fclose(out);
201 return 1;
204 static void serve_cache(const char *socket_path, int debug)
206 struct unix_stream_listen_opts opts = UNIX_STREAM_LISTEN_OPTS_INIT;
207 int fd;
209 fd = unix_stream_listen(socket_path, &opts);
210 if (fd < 0)
211 die_errno("unable to bind to '%s'", socket_path);
213 printf("ok\n");
214 fclose(stdout);
215 if (!debug) {
216 if (!freopen("/dev/null", "w", stderr))
217 die_errno("unable to point stderr to /dev/null");
220 while (serve_cache_loop(fd))
221 ; /* nothing */
223 close(fd);
226 static const char permissions_advice[] = N_(
227 "The permissions on your socket directory are too loose; other\n"
228 "users may be able to read your cached credentials. Consider running:\n"
229 "\n"
230 " chmod 0700 %s");
231 static void init_socket_directory(const char *path)
233 struct stat st;
234 char *path_copy = xstrdup(path);
235 char *dir = dirname(path_copy);
237 if (!stat(dir, &st)) {
238 if (st.st_mode & 077)
239 die(_(permissions_advice), dir);
240 } else {
242 * We must be sure to create the directory with the correct mode,
243 * not just chmod it after the fact; otherwise, there is a race
244 * condition in which somebody can chdir to it, sleep, then try to open
245 * our protected socket.
247 if (safe_create_leading_directories_const(dir) < 0)
248 die_errno("unable to create directories for '%s'", dir);
249 if (mkdir(dir, 0700) < 0)
250 die_errno("unable to mkdir '%s'", dir);
253 if (chdir(dir))
255 * We don't actually care what our cwd is; we chdir here just to
256 * be a friendly daemon and avoid tying up our original cwd.
257 * If this fails, it's OK to just continue without that benefit.
261 free(path_copy);
264 int cmd_credential_cache_daemon(int argc, const char **argv, const char *prefix)
266 struct tempfile *socket_file;
267 const char *socket_path;
268 int ignore_sighup = 0;
269 static const char *usage[] = {
270 "git-credential-cache--daemon [opts] <socket_path>",
271 NULL
273 int debug = 0;
274 const struct option options[] = {
275 OPT_BOOL(0, "debug", &debug,
276 N_("print debugging messages to stderr")),
277 OPT_END()
280 git_config_get_bool("credentialcache.ignoresighup", &ignore_sighup);
282 argc = parse_options(argc, argv, prefix, options, usage, 0);
283 socket_path = argv[0];
285 if (!socket_path)
286 usage_with_options(usage, options);
288 if (!is_absolute_path(socket_path))
289 die("socket directory must be an absolute path");
291 init_socket_directory(socket_path);
292 socket_file = register_tempfile(socket_path);
294 if (ignore_sighup)
295 signal(SIGHUP, SIG_IGN);
297 serve_cache(socket_path, debug);
298 delete_tempfile(&socket_file);
300 return 0;
303 #else
305 int cmd_credential_cache_daemon(int argc, const char **argv, const char *prefix)
307 const char * const usage[] = {
308 "git credential-cache--daemon [options] <action>",
310 "credential-cache--daemon is disabled in this build of Git",
311 NULL
313 struct option options[] = { OPT_END() };
315 argc = parse_options(argc, argv, prefix, options, usage, 0);
316 die(_("credential-cache--daemon unavailable; no unix socket support"));
319 #endif /* NO_UNIX_SOCKET */