]>
Commit | Line | Data |
---|---|---|
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" | |
7 | ||
8 | struct credential_cache_entry { | |
9 | struct credential item; | |
10 | timestamp_t expiration; | |
11 | }; | |
12 | static struct credential_cache_entry *entries; | |
13 | static int entries_nr; | |
14 | static int entries_alloc; | |
15 | ||
16 | static void cache_credential(struct credential *c, int timeout) | |
17 | { | |
18 | struct credential_cache_entry *e; | |
19 | ||
20 | ALLOC_GROW(entries, entries_nr + 1, entries_alloc); | |
21 | e = &entries[entries_nr++]; | |
22 | ||
23 | /* take ownership of pointers */ | |
24 | memcpy(&e->item, c, sizeof(*c)); | |
25 | memset(c, 0, sizeof(*c)); | |
26 | e->expiration = time(NULL) + timeout; | |
27 | } | |
28 | ||
29 | static struct credential_cache_entry *lookup_credential(const struct credential *c) | |
30 | { | |
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]; | |
36 | } | |
37 | return NULL; | |
38 | } | |
39 | ||
40 | static void remove_credential(const struct credential *c) | |
41 | { | |
42 | struct credential_cache_entry *e; | |
43 | ||
44 | e = lookup_credential(c); | |
45 | if (e) | |
46 | e->expiration = 0; | |
47 | } | |
48 | ||
49 | static timestamp_t check_expirations(void) | |
50 | { | |
51 | static timestamp_t wait_for_entry_until; | |
52 | int i = 0; | |
53 | timestamp_t now = time(NULL); | |
54 | timestamp_t next = TIME_MAX; | |
55 | ||
56 | /* | |
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. | |
60 | */ | |
61 | if (!wait_for_entry_until) | |
62 | wait_for_entry_until = now + 30; | |
63 | ||
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)); | |
70 | /* | |
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). | |
74 | */ | |
75 | wait_for_entry_until = now + 30; | |
76 | } | |
77 | else { | |
78 | if (entries[i].expiration < next) | |
79 | next = entries[i].expiration; | |
80 | i++; | |
81 | } | |
82 | } | |
83 | ||
84 | if (!entries_nr) { | |
85 | if (wait_for_entry_until <= now) | |
86 | return 0; | |
87 | next = wait_for_entry_until; | |
88 | } | |
89 | ||
90 | return next - now; | |
91 | } | |
92 | ||
93 | static int read_request(FILE *fh, struct credential *c, | |
94 | struct strbuf *action, int *timeout) | |
95 | { | |
96 | static struct strbuf item = STRBUF_INIT; | |
97 | const char *p; | |
98 | ||
99 | strbuf_getline_lf(&item, fh); | |
100 | if (!skip_prefix(item.buf, "action=", &p)) | |
101 | return error("client sent bogus action line: %s", item.buf); | |
102 | strbuf_addstr(action, p); | |
103 | ||
104 | strbuf_getline_lf(&item, fh); | |
105 | if (!skip_prefix(item.buf, "timeout=", &p)) | |
106 | return error("client sent bogus timeout line: %s", item.buf); | |
107 | *timeout = atoi(p); | |
108 | ||
109 | if (credential_read(c, fh) < 0) | |
110 | return -1; | |
111 | return 0; | |
112 | } | |
113 | ||
114 | static void serve_one_client(FILE *in, FILE *out) | |
115 | { | |
116 | struct credential c = CREDENTIAL_INIT; | |
117 | struct strbuf action = STRBUF_INIT; | |
118 | int timeout = -1; | |
119 | ||
120 | if (read_request(in, &c, &action, &timeout) < 0) | |
121 | /* ignore error */ ; | |
122 | else if (!strcmp(action.buf, "get")) { | |
123 | struct credential_cache_entry *e = lookup_credential(&c); | |
124 | if (e) { | |
125 | fprintf(out, "username=%s\n", e->item.username); | |
126 | fprintf(out, "password=%s\n", e->item.password); | |
127 | } | |
128 | } | |
129 | else if (!strcmp(action.buf, "exit")) { | |
130 | /* | |
131 | * It's important that we clean up our socket first, and then | |
132 | * signal the client only once we have finished the cleanup. | |
133 | * Calling exit() directly does this, because we clean up in | |
134 | * our atexit() handler, and then signal the client when our | |
135 | * process actually ends, which closes the socket and gives | |
136 | * them EOF. | |
137 | */ | |
138 | exit(0); | |
139 | } | |
140 | else if (!strcmp(action.buf, "erase")) | |
141 | remove_credential(&c); | |
142 | else if (!strcmp(action.buf, "store")) { | |
143 | if (timeout < 0) | |
144 | warning("cache client didn't specify a timeout"); | |
145 | else if (!c.username || !c.password) | |
146 | warning("cache client gave us a partial credential"); | |
147 | else { | |
148 | remove_credential(&c); | |
149 | cache_credential(&c, timeout); | |
150 | } | |
151 | } | |
152 | else | |
153 | warning("cache client sent unknown action: %s", action.buf); | |
154 | ||
155 | credential_clear(&c); | |
156 | strbuf_release(&action); | |
157 | } | |
158 | ||
159 | static int serve_cache_loop(int fd) | |
160 | { | |
161 | struct pollfd pfd; | |
162 | timestamp_t wakeup; | |
163 | ||
164 | wakeup = check_expirations(); | |
165 | if (!wakeup) | |
166 | return 0; | |
167 | ||
168 | pfd.fd = fd; | |
169 | pfd.events = POLLIN; | |
170 | if (poll(&pfd, 1, 1000 * wakeup) < 0) { | |
171 | if (errno != EINTR) | |
172 | die_errno("poll failed"); | |
173 | return 1; | |
174 | } | |
175 | ||
176 | if (pfd.revents & POLLIN) { | |
177 | int client, client2; | |
178 | FILE *in, *out; | |
179 | ||
180 | client = accept(fd, NULL, NULL); | |
181 | if (client < 0) { | |
182 | warning_errno("accept failed"); | |
183 | return 1; | |
184 | } | |
185 | client2 = dup(client); | |
186 | if (client2 < 0) { | |
187 | warning_errno("dup failed"); | |
188 | close(client); | |
189 | return 1; | |
190 | } | |
191 | ||
192 | in = xfdopen(client, "r"); | |
193 | out = xfdopen(client2, "w"); | |
194 | serve_one_client(in, out); | |
195 | fclose(in); | |
196 | fclose(out); | |
197 | } | |
198 | return 1; | |
199 | } | |
200 | ||
201 | static void serve_cache(const char *socket_path, int debug) | |
202 | { | |
203 | int fd; | |
204 | ||
205 | fd = unix_stream_listen(socket_path); | |
206 | if (fd < 0) | |
207 | die_errno("unable to bind to '%s'", socket_path); | |
208 | ||
209 | printf("ok\n"); | |
210 | fclose(stdout); | |
211 | if (!debug) { | |
212 | if (!freopen("/dev/null", "w", stderr)) | |
213 | die_errno("unable to point stderr to /dev/null"); | |
214 | } | |
215 | ||
216 | while (serve_cache_loop(fd)) | |
217 | ; /* nothing */ | |
218 | ||
219 | close(fd); | |
220 | } | |
221 | ||
222 | static const char permissions_advice[] = N_( | |
223 | "The permissions on your socket directory are too loose; other\n" | |
224 | "users may be able to read your cached credentials. Consider running:\n" | |
225 | "\n" | |
226 | " chmod 0700 %s"); | |
227 | static void init_socket_directory(const char *path) | |
228 | { | |
229 | struct stat st; | |
230 | char *path_copy = xstrdup(path); | |
231 | char *dir = dirname(path_copy); | |
232 | ||
233 | if (!stat(dir, &st)) { | |
234 | if (st.st_mode & 077) | |
235 | die(_(permissions_advice), dir); | |
236 | } else { | |
237 | /* | |
238 | * We must be sure to create the directory with the correct mode, | |
239 | * not just chmod it after the fact; otherwise, there is a race | |
240 | * condition in which somebody can chdir to it, sleep, then try to open | |
241 | * our protected socket. | |
242 | */ | |
243 | if (safe_create_leading_directories_const(dir) < 0) | |
244 | die_errno("unable to create directories for '%s'", dir); | |
245 | if (mkdir(dir, 0700) < 0) | |
246 | die_errno("unable to mkdir '%s'", dir); | |
247 | } | |
248 | ||
249 | if (chdir(dir)) | |
250 | /* | |
251 | * We don't actually care what our cwd is; we chdir here just to | |
252 | * be a friendly daemon and avoid tying up our original cwd. | |
253 | * If this fails, it's OK to just continue without that benefit. | |
254 | */ | |
255 | ; | |
256 | ||
257 | free(path_copy); | |
258 | } | |
259 | ||
260 | int cmd_main(int argc, const char **argv) | |
261 | { | |
262 | struct tempfile *socket_file; | |
263 | const char *socket_path; | |
264 | int ignore_sighup = 0; | |
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 | ||
276 | git_config_get_bool("credentialcache.ignoresighup", &ignore_sighup); | |
277 | ||
278 | argc = parse_options(argc, argv, NULL, options, usage, 0); | |
279 | socket_path = argv[0]; | |
280 | ||
281 | if (!socket_path) | |
282 | usage_with_options(usage, options); | |
283 | ||
284 | if (!is_absolute_path(socket_path)) | |
285 | die("socket directory must be an absolute path"); | |
286 | ||
287 | init_socket_directory(socket_path); | |
288 | socket_file = register_tempfile(socket_path); | |
289 | ||
290 | if (ignore_sighup) | |
291 | signal(SIGHUP, SIG_IGN); | |
292 | ||
293 | serve_cache(socket_path, debug); | |
294 | delete_tempfile(&socket_file); | |
295 | ||
296 | return 0; | |
297 | } |