Merge early part of branch 'jc/daemon'
[git] / receive-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "run-command.h"
5
6 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
7
8 static const char *unpacker[] = { "unpack-objects", NULL };
9
10 static int report_status;
11
12 static char capabilities[] = "report-status";
13 static int capabilities_sent;
14
15 static int show_ref(const char *path, const unsigned char *sha1)
16 {
17         if (capabilities_sent)
18                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
19         else
20                 packet_write(1, "%s %s%c%s\n",
21                              sha1_to_hex(sha1), path, 0, capabilities);
22         capabilities_sent = 1;
23         return 0;
24 }
25
26 static void write_head_info(void)
27 {
28         for_each_ref(show_ref);
29         if (!capabilities_sent)
30                 show_ref("capabilities^{}", null_sha1);
31
32 }
33
34 struct command {
35         struct command *next;
36         const char *error_string;
37         unsigned char old_sha1[20];
38         unsigned char new_sha1[20];
39         char ref_name[FLEX_ARRAY]; /* more */
40 };
41
42 static struct command *commands;
43
44 static int is_all_zeroes(const char *hex)
45 {
46         int i;
47         for (i = 0; i < 40; i++)
48                 if (*hex++ != '0')
49                         return 0;
50         return 1;
51 }
52
53 static int verify_old_ref(const char *name, char *hex_contents)
54 {
55         int fd, ret;
56         char buffer[60];
57
58         if (is_all_zeroes(hex_contents))
59                 return 0;
60         fd = open(name, O_RDONLY);
61         if (fd < 0)
62                 return -1;
63         ret = read(fd, buffer, 40);
64         close(fd);
65         if (ret != 40)
66                 return -1;
67         if (memcmp(buffer, hex_contents, 40))
68                 return -1;
69         return 0;
70 }
71
72 static char update_hook[] = "hooks/update";
73
74 static int run_update_hook(const char *refname,
75                            char *old_hex, char *new_hex)
76 {
77         int code;
78
79         if (access(update_hook, X_OK) < 0)
80                 return 0;
81         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
82         switch (code) {
83         case 0:
84                 return 0;
85         case -ERR_RUN_COMMAND_FORK:
86                 return error("hook fork failed");
87         case -ERR_RUN_COMMAND_EXEC:
88                 return error("hook execute failed");
89         case -ERR_RUN_COMMAND_WAITPID:
90                 return error("waitpid failed");
91         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
92                 return error("waitpid is confused");
93         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
94                 return error("%s died of signal", update_hook);
95         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
96                 return error("%s died strangely", update_hook);
97         default:
98                 error("%s exited with error code %d", update_hook, -code);
99                 return -code;
100         }
101 }
102
103 static int update(struct command *cmd)
104 {
105         const char *name = cmd->ref_name;
106         unsigned char *old_sha1 = cmd->old_sha1;
107         unsigned char *new_sha1 = cmd->new_sha1;
108         char new_hex[60], *old_hex, *lock_name;
109         int newfd, namelen, written;
110
111         cmd->error_string = NULL;
112         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
113                 cmd->error_string = "funny refname";
114                 return error("refusing to create funny ref '%s' locally",
115                              name);
116         }
117
118         namelen = strlen(name);
119         lock_name = xmalloc(namelen + 10);
120         memcpy(lock_name, name, namelen);
121         memcpy(lock_name + namelen, ".lock", 6);
122
123         strcpy(new_hex, sha1_to_hex(new_sha1));
124         old_hex = sha1_to_hex(old_sha1);
125         if (!has_sha1_file(new_sha1)) {
126                 cmd->error_string = "bad pack";
127                 return error("unpack should have generated %s, "
128                              "but I can't find it!", new_hex);
129         }
130         safe_create_leading_directories(lock_name);
131
132         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
133         if (newfd < 0) {
134                 cmd->error_string = "can't lock";
135                 return error("unable to create %s (%s)",
136                              lock_name, strerror(errno));
137         }
138
139         /* Write the ref with an ending '\n' */
140         new_hex[40] = '\n';
141         new_hex[41] = 0;
142         written = write(newfd, new_hex, 41);
143         /* Remove the '\n' again */
144         new_hex[40] = 0;
145
146         close(newfd);
147         if (written != 41) {
148                 unlink(lock_name);
149                 cmd->error_string = "can't write";
150                 return error("unable to write %s", lock_name);
151         }
152         if (verify_old_ref(name, old_hex) < 0) {
153                 unlink(lock_name);
154                 cmd->error_string = "raced";
155                 return error("%s changed during push", name);
156         }
157         if (run_update_hook(name, old_hex, new_hex)) {
158                 unlink(lock_name);
159                 cmd->error_string = "hook declined";
160                 return error("hook declined to update %s", name);
161         }
162         else if (rename(lock_name, name) < 0) {
163                 unlink(lock_name);
164                 cmd->error_string = "can't rename";
165                 return error("unable to replace %s", name);
166         }
167         else {
168                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
169                 return 0;
170         }
171 }
172
173 static char update_post_hook[] = "hooks/post-update";
174
175 static void run_update_post_hook(struct command *cmd)
176 {
177         struct command *cmd_p;
178         int argc;
179         const char **argv;
180
181         if (access(update_post_hook, X_OK) < 0)
182                 return;
183         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
184                 if (cmd_p->error_string)
185                         continue;
186                 argc++;
187         }
188         argv = xmalloc(sizeof(*argv) * (1 + argc));
189         argv[0] = update_post_hook;
190
191         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
192                 char *p;
193                 if (cmd_p->error_string)
194                         continue;
195                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
196                 strcpy(p, cmd_p->ref_name);
197                 argv[argc] = p;
198                 argc++;
199         }
200         argv[argc] = NULL;
201         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
202 }
203
204 /*
205  * This gets called after(if) we've successfully
206  * unpacked the data payload.
207  */
208 static void execute_commands(void)
209 {
210         struct command *cmd = commands;
211
212         while (cmd) {
213                 update(cmd);
214                 cmd = cmd->next;
215         }
216         run_update_post_hook(commands);
217 }
218
219 static void read_head_info(void)
220 {
221         struct command **p = &commands;
222         for (;;) {
223                 static char line[1000];
224                 unsigned char old_sha1[20], new_sha1[20];
225                 struct command *cmd;
226                 char *refname;
227                 int len, reflen;
228
229                 len = packet_read_line(0, line, sizeof(line));
230                 if (!len)
231                         break;
232                 if (line[len-1] == '\n')
233                         line[--len] = 0;
234                 if (len < 83 ||
235                     line[40] != ' ' ||
236                     line[81] != ' ' ||
237                     get_sha1_hex(line, old_sha1) ||
238                     get_sha1_hex(line + 41, new_sha1))
239                         die("protocol error: expected old/new/ref, got '%s'",
240                             line);
241
242                 refname = line + 82;
243                 reflen = strlen(refname);
244                 if (reflen + 82 < len) {
245                         if (strstr(refname + reflen + 1, "report-status"))
246                                 report_status = 1;
247                 }
248                 cmd = xmalloc(sizeof(struct command) + len - 80);
249                 hashcpy(cmd->old_sha1, old_sha1);
250                 hashcpy(cmd->new_sha1, new_sha1);
251                 memcpy(cmd->ref_name, line + 82, len - 81);
252                 cmd->error_string = "n/a (unpacker error)";
253                 cmd->next = NULL;
254                 *p = cmd;
255                 p = &cmd->next;
256         }
257 }
258
259 static const char *unpack(int *error_code)
260 {
261         int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
262
263         *error_code = 0;
264         switch (code) {
265         case 0:
266                 return NULL;
267         case -ERR_RUN_COMMAND_FORK:
268                 return "unpack fork failed";
269         case -ERR_RUN_COMMAND_EXEC:
270                 return "unpack execute failed";
271         case -ERR_RUN_COMMAND_WAITPID:
272                 return "waitpid failed";
273         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
274                 return "waitpid is confused";
275         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
276                 return "unpacker died of signal";
277         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
278                 return "unpacker died strangely";
279         default:
280                 *error_code = -code;
281                 return "unpacker exited with error code";
282         }
283 }
284
285 static void report(const char *unpack_status)
286 {
287         struct command *cmd;
288         packet_write(1, "unpack %s\n",
289                      unpack_status ? unpack_status : "ok");
290         for (cmd = commands; cmd; cmd = cmd->next) {
291                 if (!cmd->error_string)
292                         packet_write(1, "ok %s\n",
293                                      cmd->ref_name);
294                 else
295                         packet_write(1, "ng %s %s\n",
296                                      cmd->ref_name, cmd->error_string);
297         }
298         packet_flush(1);
299 }
300
301 int main(int argc, char **argv)
302 {
303         int i;
304         char *dir = NULL;
305
306         argv++;
307         for (i = 1; i < argc; i++) {
308                 char *arg = *argv++;
309
310                 if (*arg == '-') {
311                         /* Do flag handling here */
312                         usage(receive_pack_usage);
313                 }
314                 if (dir)
315                         usage(receive_pack_usage);
316                 dir = arg;
317         }
318         if (!dir)
319                 usage(receive_pack_usage);
320
321         if(!enter_repo(dir, 0))
322                 die("'%s': unable to chdir or not a git archive", dir);
323
324         write_head_info();
325
326         /* EOF */
327         packet_flush(1);
328
329         read_head_info();
330         if (commands) {
331                 int code;
332                 const char *unpack_status = unpack(&code);
333                 if (!unpack_status)
334                         execute_commands();
335                 if (report_status)
336                         report(unpack_status);
337         }
338         return 0;
339 }