tempfile: remove deactivated list entries
[git/git.git] / credential-cache--daemon.c
CommitLineData
e2770979 1#include "cache.h"
b2141fc1 2#include "config.h"
9e903316 3#include "tempfile.h"
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4#include "credential.h"
5#include "unix-socket.h"
f5e3c0b9 6#include "parse-options.h"
e2770979 7
9e903316 8static struct tempfile socket_file;
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9
10struct credential_cache_entry {
11 struct credential item;
dddbad72 12 timestamp_t expiration;
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13};
14static struct credential_cache_entry *entries;
15static int entries_nr;
16static int entries_alloc;
17
18static void cache_credential(struct credential *c, int timeout)
19{
20 struct credential_cache_entry *e;
21
22 ALLOC_GROW(entries, entries_nr + 1, entries_alloc);
23 e = &entries[entries_nr++];
24
25 /* take ownership of pointers */
26 memcpy(&e->item, c, sizeof(*c));
27 memset(c, 0, sizeof(*c));
28 e->expiration = time(NULL) + timeout;
29}
30
31static struct credential_cache_entry *lookup_credential(const struct credential *c)
32{
33 int i;
34 for (i = 0; i < entries_nr; i++) {
35 struct credential *e = &entries[i].item;
36 if (credential_match(c, e))
37 return &entries[i];
38 }
39 return NULL;
40}
41
42static void remove_credential(const struct credential *c)
43{
44 struct credential_cache_entry *e;
45
46 e = lookup_credential(c);
47 if (e)
48 e->expiration = 0;
49}
50
dddbad72 51static timestamp_t check_expirations(void)
e2770979 52{
dddbad72 53 static timestamp_t wait_for_entry_until;
e2770979 54 int i = 0;
dddbad72
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55 timestamp_t now = time(NULL);
56 timestamp_t next = TIME_MAX;
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57
58 /*
59 * Initially give the client 30 seconds to actually contact us
60 * and store a credential before we decide there's no point in
61 * keeping the daemon around.
62 */
63 if (!wait_for_entry_until)
64 wait_for_entry_until = now + 30;
65
66 while (i < entries_nr) {
67 if (entries[i].expiration <= now) {
68 entries_nr--;
69 credential_clear(&entries[i].item);
70 if (i != entries_nr)
71 memcpy(&entries[i], &entries[entries_nr], sizeof(*entries));
72 /*
73 * Stick around 30 seconds in case a new credential
74 * shows up (e.g., because we just removed a failed
75 * one, and we will soon get the correct one).
76 */
77 wait_for_entry_until = now + 30;
78 }
79 else {
80 if (entries[i].expiration < next)
81 next = entries[i].expiration;
82 i++;
83 }
84 }
85
86 if (!entries_nr) {
87 if (wait_for_entry_until <= now)
88 return 0;
89 next = wait_for_entry_until;
90 }
91
92 return next - now;
93}
94
95static int read_request(FILE *fh, struct credential *c,
96 struct strbuf *action, int *timeout) {
97 static struct strbuf item = STRBUF_INIT;
98 const char *p;
99
8f309aeb 100 strbuf_getline_lf(&item, fh);
cf4fff57 101 if (!skip_prefix(item.buf, "action=", &p))
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102 return error("client sent bogus action line: %s", item.buf);
103 strbuf_addstr(action, p);
104
8f309aeb 105 strbuf_getline_lf(&item, fh);
cf4fff57 106 if (!skip_prefix(item.buf, "timeout=", &p))
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107 return error("client sent bogus timeout line: %s", item.buf);
108 *timeout = atoi(p);
109
110 if (credential_read(c, fh) < 0)
111 return -1;
112 return 0;
113}
114
115static void serve_one_client(FILE *in, FILE *out)
116{
117 struct credential c = CREDENTIAL_INIT;
118 struct strbuf action = STRBUF_INIT;
119 int timeout = -1;
120
121 if (read_request(in, &c, &action, &timeout) < 0)
122 /* ignore error */ ;
123 else if (!strcmp(action.buf, "get")) {
124 struct credential_cache_entry *e = lookup_credential(&c);
125 if (e) {
126 fprintf(out, "username=%s\n", e->item.username);
127 fprintf(out, "password=%s\n", e->item.password);
128 }
129 }
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130 else if (!strcmp(action.buf, "exit")) {
131 /*
132 * It's important that we clean up our socket first, and then
133 * signal the client only once we have finished the cleanup.
134 * Calling exit() directly does this, because we clean up in
135 * our atexit() handler, and then signal the client when our
136 * process actually ends, which closes the socket and gives
137 * them EOF.
138 */
e2770979 139 exit(0);
7d5e9c98 140 }
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141 else if (!strcmp(action.buf, "erase"))
142 remove_credential(&c);
143 else if (!strcmp(action.buf, "store")) {
144 if (timeout < 0)
145 warning("cache client didn't specify a timeout");
146 else if (!c.username || !c.password)
147 warning("cache client gave us a partial credential");
148 else {
149 remove_credential(&c);
150 cache_credential(&c, timeout);
151 }
152 }
153 else
154 warning("cache client sent unknown action: %s", action.buf);
155
156 credential_clear(&c);
157 strbuf_release(&action);
158}
159
160static int serve_cache_loop(int fd)
161{
162 struct pollfd pfd;
dddbad72 163 timestamp_t wakeup;
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164
165 wakeup = check_expirations();
166 if (!wakeup)
167 return 0;
168
169 pfd.fd = fd;
170 pfd.events = POLLIN;
171 if (poll(&pfd, 1, 1000 * wakeup) < 0) {
172 if (errno != EINTR)
173 die_errno("poll failed");
174 return 1;
175 }
176
177 if (pfd.revents & POLLIN) {
178 int client, client2;
179 FILE *in, *out;
180
181 client = accept(fd, NULL, NULL);
182 if (client < 0) {
26604f9f 183 warning_errno("accept failed");
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184 return 1;
185 }
186 client2 = dup(client);
187 if (client2 < 0) {
26604f9f 188 warning_errno("dup failed");
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189 close(client);
190 return 1;
191 }
192
193 in = xfdopen(client, "r");
194 out = xfdopen(client2, "w");
195 serve_one_client(in, out);
196 fclose(in);
197 fclose(out);
198 }
199 return 1;
200}
201
f5e3c0b9 202static void serve_cache(const char *socket_path, int debug)
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203{
204 int fd;
205
206 fd = unix_stream_listen(socket_path);
207 if (fd < 0)
208 die_errno("unable to bind to '%s'", socket_path);
209
210 printf("ok\n");
211 fclose(stdout);
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212 if (!debug) {
213 if (!freopen("/dev/null", "w", stderr))
214 die_errno("unable to point stderr to /dev/null");
215 }
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216
217 while (serve_cache_loop(fd))
218 ; /* nothing */
219
220 close(fd);
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221}
222
af64f20b 223static const char permissions_advice[] = N_(
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224"The permissions on your socket directory are too loose; other\n"
225"users may be able to read your cached credentials. Consider running:\n"
226"\n"
af64f20b 227" chmod 0700 %s");
a6e5e286 228static void init_socket_directory(const char *path)
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229{
230 struct stat st;
231 char *path_copy = xstrdup(path);
232 char *dir = dirname(path_copy);
233
234 if (!stat(dir, &st)) {
235 if (st.st_mode & 077)
af64f20b 236 die(_(permissions_advice), dir);
a6e5e286
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237 } else {
238 /*
239 * We must be sure to create the directory with the correct mode,
240 * not just chmod it after the fact; otherwise, there is a race
241 * condition in which somebody can chdir to it, sleep, then try to open
242 * our protected socket.
243 */
244 if (safe_create_leading_directories_const(dir) < 0)
245 die_errno("unable to create directories for '%s'", dir);
246 if (mkdir(dir, 0700) < 0)
247 die_errno("unable to mkdir '%s'", dir);
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248 }
249
6e614490
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250 if (chdir(dir))
251 /*
252 * We don't actually care what our cwd is; we chdir here just to
253 * be a friendly daemon and avoid tying up our original cwd.
254 * If this fails, it's OK to just continue without that benefit.
255 */
256 ;
257
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258 free(path_copy);
259}
260
3f2e2297 261int cmd_main(int argc, const char **argv)
e2770979 262{
9e903316 263 const char *socket_path;
7f4d4746 264 int ignore_sighup = 0;
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265 static const char *usage[] = {
266 "git-credential-cache--daemon [opts] <socket_path>",
267 NULL
268 };
269 int debug = 0;
270 const struct option options[] = {
271 OPT_BOOL(0, "debug", &debug,
272 N_("print debugging messages to stderr")),
273 OPT_END()
274 };
275
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276 git_config_get_bool("credentialcache.ignoresighup", &ignore_sighup);
277
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278 argc = parse_options(argc, argv, NULL, options, usage, 0);
279 socket_path = argv[0];
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280
281 if (!socket_path)
f5e3c0b9 282 usage_with_options(usage, options);
e2770979 283
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284 if (!is_absolute_path(socket_path))
285 die("socket directory must be an absolute path");
286
a6e5e286 287 init_socket_directory(socket_path);
9e903316 288 register_tempfile(&socket_file, socket_path);
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289
290 if (ignore_sighup)
291 signal(SIGHUP, SIG_IGN);
292
f5e3c0b9 293 serve_cache(socket_path, debug);
9e903316 294 delete_tempfile(&socket_file);
18a3de42 295
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296 return 0;
297}