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Junio C Hamano
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send-pack/receive-pack: allow errors to be reported back to pusher.
This updates the protocol between git-send-pack/git-receive-pack in a backward compatible way to allow failures at the receiving end to be propagated back to the sender. Most notably, versions of git-push before this could not notice if the update hook on the receiving end refused to update the ref for its own policy reasons. Signed-off-by: Junio C Hamano <junkio@cox.net>
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3 files changed

+148
-39
lines changed

3 files changed

+148
-39
lines changed

‎connect.c‎

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -34,17 +34,17 @@ struct ref **get_remote_heads(int in, struct ref **list,
3434
die("protocol error: expected sha/ref, got '%s'", buffer);
3535
name = buffer + 41;
3636

37-
if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
38-
check_ref_format(name + 5))
39-
continue;
40-
4137
name_len = strlen(name);
4238
if (len != name_len + 41) {
4339
if (server_capabilities)
4440
free(server_capabilities);
4541
server_capabilities = strdup(name + name_len + 1);
4642
}
4743

44+
if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
45+
check_ref_format(name + 5))
46+
continue;
47+
4848
if (nr_match && !path_match(name, nr_match, match))
4949
continue;
5050
ref = xcalloc(1, sizeof(*ref) + len - 40);

‎receive-pack.c‎

Lines changed: 88 additions & 32 deletions
Original file line numberDiff line numberDiff line change
@@ -8,20 +8,33 @@ static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
88

99
static const char unpacker[] = "git-unpack-objects";
1010

11+
static int report_status = 0;
12+
13+
static char capabilities[] = "report-status";
14+
static int capabilities_sent = 0;
15+
1116
static int show_ref(const char *path, const unsigned char *sha1)
1217
{
13-
packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
18+
if (capabilities_sent)
19+
packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
20+
else
21+
packet_write(1, "%s %s%c%s\n",
22+
sha1_to_hex(sha1), path, 0, capabilities);
23+
capabilities_sent = 1;
1424
return 0;
1525
}
1626

1727
static void write_head_info(void)
1828
{
1929
for_each_ref(show_ref);
30+
if (!capabilities_sent)
31+
show_ref("capabilities^{}", null_sha1);
32+
2033
}
2134

2235
struct command {
2336
struct command *next;
24-
unsigned char updated;
37+
const char *error_string;
2538
unsigned char old_sha1[20];
2639
unsigned char new_sha1[20];
2740
char ref_name[0];
@@ -71,33 +84,37 @@ static int run_update_hook(const char *refname,
7184
case 0:
7285
return 0;
7386
case -ERR_RUN_COMMAND_FORK:
74-
die("hook fork failed");
87+
return error("hook fork failed");
7588
case -ERR_RUN_COMMAND_EXEC:
76-
die("hook execute failed");
89+
return error("hook execute failed");
7790
case -ERR_RUN_COMMAND_WAITPID:
78-
die("waitpid failed");
91+
return error("waitpid failed");
7992
case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
80-
die("waitpid is confused");
93+
return error("waitpid is confused");
8194
case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
82-
fprintf(stderr, "%s died of signal\n", update_hook);
83-
return -1;
95+
return error("%s died of signal\n", update_hook);
8496
case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
85-
die("%s died strangely", update_hook);
97+
return error("%s died strangely", update_hook);
8698
default:
8799
error("%s exited with error code %d", update_hook, -code);
88100
return -code;
89101
}
90102
}
91103

92-
static int update(const char *name,
93-
unsigned char *old_sha1, unsigned char *new_sha1)
104+
static int update(struct command *cmd)
94105
{
106+
const char *name = cmd->ref_name;
107+
unsigned char *old_sha1 = cmd->old_sha1;
108+
unsigned char *new_sha1 = cmd->new_sha1;
95109
char new_hex[60], *old_hex, *lock_name;
96110
int newfd, namelen, written;
97111

98-
if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5))
112+
cmd->error_string = NULL;
113+
if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
114+
cmd->error_string = "funny refname";
99115
return error("refusing to create funny ref '%s' locally",
100116
name);
117+
}
101118

102119
namelen = strlen(name);
103120
lock_name = xmalloc(namelen + 10);
@@ -106,16 +123,19 @@ static int update(const char *name,
106123

107124
strcpy(new_hex, sha1_to_hex(new_sha1));
108125
old_hex = sha1_to_hex(old_sha1);
109-
if (!has_sha1_file(new_sha1))
126+
if (!has_sha1_file(new_sha1)) {
127+
cmd->error_string = "bad pack";
110128
return error("unpack should have generated %s, "
111129
"but I can't find it!", new_hex);
112-
130+
}
113131
safe_create_leading_directories(lock_name);
114132

115133
newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
116-
if (newfd < 0)
134+
if (newfd < 0) {
135+
cmd->error_string = "can't lock";
117136
return error("unable to create %s (%s)",
118137
lock_name, strerror(errno));
138+
}
119139

120140
/* Write the ref with an ending '\n' */
121141
new_hex[40] = '\n';
@@ -127,18 +147,22 @@ static int update(const char *name,
127147
close(newfd);
128148
if (written != 41) {
129149
unlink(lock_name);
150+
cmd->error_string = "can't write";
130151
return error("unable to write %s", lock_name);
131152
}
132153
if (verify_old_ref(name, old_hex) < 0) {
133154
unlink(lock_name);
155+
cmd->error_string = "raced";
134156
return error("%s changed during push", name);
135157
}
136158
if (run_update_hook(name, old_hex, new_hex)) {
137159
unlink(lock_name);
160+
cmd->error_string = "hook declined";
138161
return error("hook declined to update %s\n", name);
139162
}
140163
else if (rename(lock_name, name) < 0) {
141164
unlink(lock_name);
165+
cmd->error_string = "can't rename";
142166
return error("unable to replace %s", name);
143167
}
144168
else {
@@ -158,15 +182,15 @@ static void run_update_post_hook(struct command *cmd)
158182
if (access(update_post_hook, X_OK) < 0)
159183
return;
160184
for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
161-
if (!cmd_p->updated)
185+
if (cmd_p->error_string)
162186
continue;
163187
argc++;
164188
}
165189
argv = xmalloc(sizeof(*argv) * (1 + argc));
166190
argv[0] = update_post_hook;
167191

168192
for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
169-
if (!cmd_p->updated)
193+
if (cmd_p->error_string)
170194
continue;
171195
argv[argc] = xmalloc(strlen(cmd_p->ref_name) + 1);
172196
strcpy(argv[argc], cmd_p->ref_name);
@@ -185,8 +209,7 @@ static void execute_commands(void)
185209
struct command *cmd = commands;
186210

187211
while (cmd) {
188-
cmd->updated = !update(cmd->ref_name,
189-
cmd->old_sha1, cmd->new_sha1);
212+
update(cmd);
190213
cmd = cmd->next;
191214
}
192215
run_update_post_hook(commands);
@@ -199,7 +222,8 @@ static void read_head_info(void)
199222
static char line[1000];
200223
unsigned char old_sha1[20], new_sha1[20];
201224
struct command *cmd;
202-
int len;
225+
char *refname;
226+
int len, reflen;
203227

204228
len = packet_read_line(0, line, sizeof(line));
205229
if (!len)
@@ -211,38 +235,66 @@ static void read_head_info(void)
211235
line[81] != ' ' ||
212236
get_sha1_hex(line, old_sha1) ||
213237
get_sha1_hex(line + 41, new_sha1))
214-
die("protocol error: expected old/new/ref, got '%s'", line);
238+
die("protocol error: expected old/new/ref, got '%s'",
239+
line);
240+
241+
refname = line + 82;
242+
reflen = strlen(refname);
243+
if (reflen + 82 < len) {
244+
if (strstr(refname + reflen + 1, "report-status"))
245+
report_status = 1;
246+
}
215247
cmd = xmalloc(sizeof(struct command) + len - 80);
216248
memcpy(cmd->old_sha1, old_sha1, 20);
217249
memcpy(cmd->new_sha1, new_sha1, 20);
218250
memcpy(cmd->ref_name, line + 82, len - 81);
251+
cmd->error_string = "n/a (unpacker error)";
219252
cmd->next = NULL;
220253
*p = cmd;
221254
p = &cmd->next;
222255
}
223256
}
224257

225-
static void unpack(void)
258+
static const char *unpack(int *error_code)
226259
{
227260
int code = run_command(unpacker, NULL);
261+
262+
*error_code = 0;
228263
switch (code) {
229264
case 0:
230-
return;
265+
return NULL;
231266
case -ERR_RUN_COMMAND_FORK:
232-
die("unpack fork failed");
267+
return "unpack fork failed";
233268
case -ERR_RUN_COMMAND_EXEC:
234-
die("unpack execute failed");
269+
return "unpack execute failed";
235270
case -ERR_RUN_COMMAND_WAITPID:
236-
die("waitpid failed");
271+
return "waitpid failed";
237272
case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
238-
die("waitpid is confused");
273+
return "waitpid is confused";
239274
case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
240-
die("%s died of signal", unpacker);
275+
return "unpacker died of signal";
241276
case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
242-
die("%s died strangely", unpacker);
277+
return "unpacker died strangely";
243278
default:
244-
die("%s exited with error code %d", unpacker, -code);
279+
*error_code = -code;
280+
return "unpacker exited with error code";
281+
}
282+
}
283+
284+
static void report(const char *unpack_status)
285+
{
286+
struct command *cmd;
287+
packet_write(1, "unpack %s\n",
288+
unpack_status ? unpack_status : "ok");
289+
for (cmd = commands; cmd; cmd = cmd->next) {
290+
if (!cmd->error_string)
291+
packet_write(1, "ok %s\n",
292+
cmd->ref_name);
293+
else
294+
packet_write(1, "ng %s %s\n",
295+
cmd->ref_name, cmd->error_string);
245296
}
297+
packet_flush(1);
246298
}
247299

248300
int main(int argc, char **argv)
@@ -275,8 +327,12 @@ int main(int argc, char **argv)
275327

276328
read_head_info();
277329
if (commands) {
278-
unpack();
279-
execute_commands();
330+
int code;
331+
const char *unpack_status = unpack(&code);
332+
if (!unpack_status)
333+
execute_commands();
334+
if (report_status)
335+
report(unpack_status);
280336
}
281337
return 0;
282338
}

‎send-pack.c‎

Lines changed: 56 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -176,16 +176,53 @@ static void get_local_heads(void)
176176
for_each_ref(one_local_ref);
177177
}
178178

179+
static int receive_status(int in)
180+
{
181+
char line[1000];
182+
int ret = 0;
183+
int len = packet_read_line(in, line, sizeof(line));
184+
if (len < 10 || memcmp(line, "unpack ", 7)) {
185+
fprintf(stderr, "did not receive status back\n");
186+
return -1;
187+
}
188+
if (memcmp(line, "unpack ok\n", 10)) {
189+
fputs(line, stderr);
190+
ret = -1;
191+
}
192+
while (1) {
193+
len = packet_read_line(in, line, sizeof(line));
194+
if (!len)
195+
break;
196+
if (len < 3 ||
197+
(memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
198+
fprintf(stderr, "protocol error: %s\n", line);
199+
ret = -1;
200+
break;
201+
}
202+
if (!memcmp(line, "ok", 2))
203+
continue;
204+
fputs(line, stderr);
205+
ret = -1;
206+
}
207+
return ret;
208+
}
209+
179210
static int send_pack(int in, int out, int nr_refspec, char **refspec)
180211
{
181212
struct ref *ref;
182213
int new_refs;
183214
int ret = 0;
215+
int ask_for_status_report = 0;
216+
int expect_status_report = 0;
184217

185218
/* No funny business with the matcher */
186219
remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
187220
get_local_heads();
188221

222+
/* Does the other end support the reporting? */
223+
if (server_supports("report-status"))
224+
ask_for_status_report = 1;
225+
189226
/* match them up */
190227
if (!remote_tail)
191228
remote_tail = &remote_refs;
@@ -260,7 +297,17 @@ static int send_pack(int in, int out, int nr_refspec, char **refspec)
260297
new_refs++;
261298
strcpy(old_hex, sha1_to_hex(ref->old_sha1));
262299
new_hex = sha1_to_hex(ref->new_sha1);
263-
packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
300+
301+
if (ask_for_status_report) {
302+
packet_write(out, "%s %s %s%c%s",
303+
old_hex, new_hex, ref->name, 0,
304+
"report-status");
305+
ask_for_status_report = 0;
306+
expect_status_report = 1;
307+
}
308+
else
309+
packet_write(out, "%s %s %s",
310+
old_hex, new_hex, ref->name);
264311
fprintf(stderr, "updating '%s'", ref->name);
265312
if (strcmp(ref->name, ref->peer_ref->name))
266313
fprintf(stderr, " using '%s'", ref->peer_ref->name);
@@ -270,9 +317,15 @@ static int send_pack(int in, int out, int nr_refspec, char **refspec)
270317
packet_flush(out);
271318
if (new_refs)
272319
pack_objects(out, remote_refs);
273-
else if (ret == 0)
274-
fprintf(stderr, "Everything up-to-date\n");
275320
close(out);
321+
322+
if (expect_status_report) {
323+
if (receive_status(in))
324+
ret = -4;
325+
}
326+
327+
if (!new_refs && ret == 0)
328+
fprintf(stderr, "Everything up-to-date\n");
276329
return ret;
277330
}
278331

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