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Commit | Line | Data |
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e2770979 | 1 | #include "cache.h" |
9e903316 | 2 | #include "tempfile.h" |
e2770979 JK |
3 | #include "credential.h" |
4 | #include "unix-socket.h" | |
5 | #include "sigchain.h" | |
f5e3c0b9 | 6 | #include "parse-options.h" |
e2770979 | 7 | |
9e903316 | 8 | static struct tempfile socket_file; |
e2770979 JK |
9 | |
10 | struct credential_cache_entry { | |
11 | struct credential item; | |
12 | unsigned long expiration; | |
13 | }; | |
14 | static struct credential_cache_entry *entries; | |
15 | static int entries_nr; | |
16 | static int entries_alloc; | |
17 | ||
18 | static 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 | ||
31 | static 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 | ||
42 | static 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 | ||
51 | static int check_expirations(void) | |
52 | { | |
53 | static unsigned long wait_for_entry_until; | |
54 | int i = 0; | |
55 | unsigned long now = time(NULL); | |
56 | unsigned long next = (unsigned long)-1; | |
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 | ||
95 | static 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 | ||
100 | strbuf_getline(&item, fh, '\n'); | |
cf4fff57 | 101 | if (!skip_prefix(item.buf, "action=", &p)) |
e2770979 JK |
102 | return error("client sent bogus action line: %s", item.buf); |
103 | strbuf_addstr(action, p); | |
104 | ||
105 | strbuf_getline(&item, fh, '\n'); | |
cf4fff57 | 106 | if (!skip_prefix(item.buf, "timeout=", &p)) |
e2770979 JK |
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 | ||
115 | static 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 | } | |
130 | else if (!strcmp(action.buf, "exit")) | |
131 | exit(0); | |
132 | else if (!strcmp(action.buf, "erase")) | |
133 | remove_credential(&c); | |
134 | else if (!strcmp(action.buf, "store")) { | |
135 | if (timeout < 0) | |
136 | warning("cache client didn't specify a timeout"); | |
137 | else if (!c.username || !c.password) | |
138 | warning("cache client gave us a partial credential"); | |
139 | else { | |
140 | remove_credential(&c); | |
141 | cache_credential(&c, timeout); | |
142 | } | |
143 | } | |
144 | else | |
145 | warning("cache client sent unknown action: %s", action.buf); | |
146 | ||
147 | credential_clear(&c); | |
148 | strbuf_release(&action); | |
149 | } | |
150 | ||
151 | static int serve_cache_loop(int fd) | |
152 | { | |
153 | struct pollfd pfd; | |
154 | unsigned long wakeup; | |
155 | ||
156 | wakeup = check_expirations(); | |
157 | if (!wakeup) | |
158 | return 0; | |
159 | ||
160 | pfd.fd = fd; | |
161 | pfd.events = POLLIN; | |
162 | if (poll(&pfd, 1, 1000 * wakeup) < 0) { | |
163 | if (errno != EINTR) | |
164 | die_errno("poll failed"); | |
165 | return 1; | |
166 | } | |
167 | ||
168 | if (pfd.revents & POLLIN) { | |
169 | int client, client2; | |
170 | FILE *in, *out; | |
171 | ||
172 | client = accept(fd, NULL, NULL); | |
173 | if (client < 0) { | |
174 | warning("accept failed: %s", strerror(errno)); | |
175 | return 1; | |
176 | } | |
177 | client2 = dup(client); | |
178 | if (client2 < 0) { | |
179 | warning("dup failed: %s", strerror(errno)); | |
180 | close(client); | |
181 | return 1; | |
182 | } | |
183 | ||
184 | in = xfdopen(client, "r"); | |
185 | out = xfdopen(client2, "w"); | |
186 | serve_one_client(in, out); | |
187 | fclose(in); | |
188 | fclose(out); | |
189 | } | |
190 | return 1; | |
191 | } | |
192 | ||
f5e3c0b9 | 193 | static void serve_cache(const char *socket_path, int debug) |
e2770979 JK |
194 | { |
195 | int fd; | |
196 | ||
197 | fd = unix_stream_listen(socket_path); | |
198 | if (fd < 0) | |
199 | die_errno("unable to bind to '%s'", socket_path); | |
200 | ||
201 | printf("ok\n"); | |
202 | fclose(stdout); | |
f5e3c0b9 JK |
203 | if (!debug) { |
204 | if (!freopen("/dev/null", "w", stderr)) | |
205 | die_errno("unable to point stderr to /dev/null"); | |
206 | } | |
e2770979 JK |
207 | |
208 | while (serve_cache_loop(fd)) | |
209 | ; /* nothing */ | |
210 | ||
211 | close(fd); | |
e2770979 JK |
212 | } |
213 | ||
214 | static const char permissions_advice[] = | |
215 | "The permissions on your socket directory are too loose; other\n" | |
216 | "users may be able to read your cached credentials. Consider running:\n" | |
217 | "\n" | |
218 | " chmod 0700 %s"; | |
219 | static void check_socket_directory(const char *path) | |
220 | { | |
221 | struct stat st; | |
222 | char *path_copy = xstrdup(path); | |
223 | char *dir = dirname(path_copy); | |
224 | ||
225 | if (!stat(dir, &st)) { | |
226 | if (st.st_mode & 077) | |
227 | die(permissions_advice, dir); | |
228 | free(path_copy); | |
229 | return; | |
230 | } | |
231 | ||
232 | /* | |
233 | * We must be sure to create the directory with the correct mode, | |
234 | * not just chmod it after the fact; otherwise, there is a race | |
235 | * condition in which somebody can chdir to it, sleep, then try to open | |
236 | * our protected socket. | |
237 | */ | |
238 | if (safe_create_leading_directories_const(dir) < 0) | |
239 | die_errno("unable to create directories for '%s'", dir); | |
240 | if (mkdir(dir, 0700) < 0) | |
241 | die_errno("unable to mkdir '%s'", dir); | |
242 | free(path_copy); | |
243 | } | |
244 | ||
245 | int main(int argc, const char **argv) | |
246 | { | |
9e903316 | 247 | const char *socket_path; |
f5e3c0b9 JK |
248 | static const char *usage[] = { |
249 | "git-credential-cache--daemon [opts] <socket_path>", | |
250 | NULL | |
251 | }; | |
252 | int debug = 0; | |
253 | const struct option options[] = { | |
254 | OPT_BOOL(0, "debug", &debug, | |
255 | N_("print debugging messages to stderr")), | |
256 | OPT_END() | |
257 | }; | |
258 | ||
259 | argc = parse_options(argc, argv, NULL, options, usage, 0); | |
260 | socket_path = argv[0]; | |
e2770979 JK |
261 | |
262 | if (!socket_path) | |
f5e3c0b9 | 263 | usage_with_options(usage, options); |
e2770979 | 264 | |
9e903316 MH |
265 | check_socket_directory(socket_path); |
266 | register_tempfile(&socket_file, socket_path); | |
f5e3c0b9 | 267 | serve_cache(socket_path, debug); |
9e903316 | 268 | delete_tempfile(&socket_file); |
18a3de42 | 269 | |
e2770979 JK |
270 | return 0; |
271 | } |