start_command: report child process setup errors to the parent's stderr
[git/dscho.git] / builtin-upload-archive.c
blob73f788ef247febabbabe9bc0d21a890afa198cff
1 /*
2 * Copyright (c) 2006 Franck Bui-Huu
3 */
4 #include "cache.h"
5 #include "builtin.h"
6 #include "archive.h"
7 #include "pkt-line.h"
8 #include "sideband.h"
10 static const char upload_archive_usage[] =
11 "git upload-archive <repo>";
13 static const char deadchild[] =
14 "git upload-archive: archiver died with error";
16 static const char lostchild[] =
17 "git upload-archive: archiver process was lost";
19 #define MAX_ARGS (64)
21 static int run_upload_archive(int argc, const char **argv, const char *prefix)
23 const char *sent_argv[MAX_ARGS];
24 const char *arg_cmd = "argument ";
25 char *p, buf[4096];
26 int sent_argc;
27 int len;
29 if (argc != 2)
30 usage(upload_archive_usage);
32 if (strlen(argv[1]) + 1 > sizeof(buf))
33 die("insanely long repository name");
35 strcpy(buf, argv[1]); /* enter-repo smudges its argument */
37 if (!enter_repo(buf, 0))
38 die("'%s' does not appear to be a git repository", buf);
40 /* put received options in sent_argv[] */
41 sent_argc = 1;
42 sent_argv[0] = "git-upload-archive";
43 for (p = buf;;) {
44 /* This will die if not enough free space in buf */
45 len = packet_read_line(0, p, (buf + sizeof buf) - p);
46 if (len == 0)
47 break; /* got a flush */
48 if (sent_argc > MAX_ARGS - 2)
49 die("Too many options (>%d)", MAX_ARGS - 2);
51 if (p[len-1] == '\n') {
52 p[--len] = 0;
54 if (len < strlen(arg_cmd) ||
55 strncmp(arg_cmd, p, strlen(arg_cmd)))
56 die("'argument' token or flush expected");
58 len -= strlen(arg_cmd);
59 memmove(p, p + strlen(arg_cmd), len);
60 sent_argv[sent_argc++] = p;
61 p += len;
62 *p++ = 0;
64 sent_argv[sent_argc] = NULL;
66 /* parse all options sent by the client */
67 return write_archive(sent_argc, sent_argv, prefix, 0);
70 __attribute__((format (printf, 1, 2)))
71 static void error_clnt(const char *fmt, ...)
73 char buf[1024];
74 va_list params;
75 int len;
77 va_start(params, fmt);
78 len = vsprintf(buf, fmt, params);
79 va_end(params);
80 send_sideband(1, 3, buf, len, LARGE_PACKET_MAX);
81 die("sent error to the client: %s", buf);
84 static ssize_t process_input(int child_fd, int band)
86 char buf[16384];
87 ssize_t sz = read(child_fd, buf, sizeof(buf));
88 if (sz < 0) {
89 if (errno != EAGAIN && errno != EINTR)
90 error_clnt("read error: %s\n", strerror(errno));
91 return sz;
93 send_sideband(1, band, buf, sz, LARGE_PACKET_MAX);
94 return sz;
97 int cmd_upload_archive(int argc, const char **argv, const char *prefix)
99 pid_t writer;
100 int fd1[2], fd2[2];
102 * Set up sideband subprocess.
104 * We (parent) monitor and read from child, sending its fd#1 and fd#2
105 * multiplexed out to our fd#1. If the child dies, we tell the other
106 * end over channel #3.
108 if (pipe(fd1) < 0 || pipe(fd2) < 0) {
109 int err = errno;
110 packet_write(1, "NACK pipe failed on the remote side\n");
111 die("upload-archive: %s", strerror(err));
113 writer = fork();
114 if (writer < 0) {
115 int err = errno;
116 packet_write(1, "NACK fork failed on the remote side\n");
117 die("upload-archive: %s", strerror(err));
119 if (!writer) {
120 /* child - connect fd#1 and fd#2 to the pipe */
121 dup2(fd1[1], 1);
122 dup2(fd2[1], 2);
123 close(fd1[1]); close(fd2[1]);
124 close(fd1[0]); close(fd2[0]); /* we do not read from pipe */
126 exit(run_upload_archive(argc, argv, prefix));
129 /* parent - read from child, multiplex and send out to fd#1 */
130 close(fd1[1]); close(fd2[1]); /* we do not write to pipe */
131 packet_write(1, "ACK\n");
132 packet_flush(1);
134 while (1) {
135 struct pollfd pfd[2];
136 int status;
138 pfd[0].fd = fd1[0];
139 pfd[0].events = POLLIN;
140 pfd[1].fd = fd2[0];
141 pfd[1].events = POLLIN;
142 if (poll(pfd, 2, -1) < 0) {
143 if (errno != EINTR) {
144 error("poll failed resuming: %s",
145 strerror(errno));
146 sleep(1);
148 continue;
150 if (pfd[1].revents & POLLIN)
151 /* Status stream ready */
152 if (process_input(pfd[1].fd, 2))
153 continue;
154 if (pfd[0].revents & POLLIN)
155 /* Data stream ready */
156 if (process_input(pfd[0].fd, 1))
157 continue;
159 if (waitpid(writer, &status, 0) < 0)
160 error_clnt("%s", lostchild);
161 else if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
162 error_clnt("%s", deadchild);
163 packet_flush(1);
164 break;
166 return 0;