send-pack.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include <sys/wait.h>
   4
   5 static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
   6
   7 static const char *exec = "git-receive-pack";
   8
   9 struct ref {
  10         struct ref *next;
  11         unsigned char old_sha1[20];
  12         unsigned char new_sha1[20];
  13         char name[0];
  14 };
  15
  16 static void exec_pack_objects(void)
  17 {
  18         static char *args[] = {
  19                 "git-pack-objects",
  20                 "--stdout",
  21                 NULL
  22         };
  23         execvp("git-pack-objects", args);
  24         die("git-pack-objects exec failed (%s)", strerror(errno));
  25 }
  26
  27 static void exec_rev_list(struct ref *refs)
  28 {
  29         static char *args[1000];
  30         int i = 0;
  31
  32         args[i++] = "git-rev-list";     /* 0 */
  33         args[i++] = "--objects";        /* 1 */
  34         while (refs) {
  35                 char *buf = malloc(100);
  36                 if (i > 900)
  37                         die("git-rev-list environment overflow");
  38                 args[i++] = buf;
  39                 snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  40                 buf += 50;
  41                 args[i++] = buf;
  42                 snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  43                 refs = refs->next;
  44         }
  45         args[i] = NULL;
  46         execvp("git-rev-list", args);
  47         die("git-rev-list exec failed (%s)", strerror(errno));
  48 }
  49
  50 static void rev_list(int fd, struct ref *refs)
  51 {
  52         int pipe_fd[2];
  53         pid_t pack_objects_pid;
  54
  55         if (pipe(pipe_fd) < 0)
  56                 die("rev-list setup: pipe failed");
  57         pack_objects_pid = fork();
  58         if (!pack_objects_pid) {
  59                 dup2(pipe_fd[0], 0);
  60                 dup2(fd, 1);
  61                 close(pipe_fd[0]);
  62                 close(pipe_fd[1]);
  63                 close(fd);
  64                 exec_pack_objects();
  65                 die("pack-objects setup failed");
  66         }
  67         if (pack_objects_pid < 0)
  68                 die("pack-objects fork failed");
  69         dup2(pipe_fd[1], 1);
  70         close(pipe_fd[0]);
  71         close(pipe_fd[1]);
  72         close(fd);
  73         exec_rev_list(refs);
  74 }
  75
  76 static int pack_objects(int fd, struct ref *refs)
  77 {
  78         pid_t rev_list_pid;
  79
  80         rev_list_pid = fork();
  81         if (!rev_list_pid) {
  82                 rev_list(fd, refs);
  83                 die("rev-list setup failed");
  84         }
  85         if (rev_list_pid < 0)
  86                 die("rev-list fork failed");
  87         /*
  88          * We don't wait for the rev-list pipeline in the parent:
  89          * we end up waiting for the other end instead
  90          */
  91 }
  92
  93 static int read_ref(const char *ref, unsigned char *sha1)
  94 {
  95         int fd, ret;
  96         static char pathname[PATH_MAX];
  97         char buffer[60];
  98         const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
  99
 100         snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, ref);
 101         fd = open(pathname, O_RDONLY);
 102         if (fd < 0)
 103                 return -1;
 104         ret = -1;
 105         if (read(fd, buffer, sizeof(buffer)) >= 40)
 106                 ret = get_sha1_hex(buffer, sha1);
 107         close(fd);
 108         return ret;
 109 }
 110
 111 static int send_pack(int in, int out)
 112 {
 113         struct ref *ref_list = NULL, **last_ref = &ref_list;
 114         struct ref *ref;
 115
 116         for (;;) {
 117                 unsigned char old_sha1[20];
 118                 unsigned char new_sha1[20];
 119                 static char buffer[1000];
 120                 char *name;
 121                 int len;
 122
 123                 len = packet_read_line(in, buffer, sizeof(buffer));
 124                 if (!len)
 125                         break;
 126                 if (buffer[len-1] == '\n')
 127                         buffer[--len] = 0;
 128
 129                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 130                         die("protocol error: expected sha/ref, got '%s'", buffer);
 131                 name = buffer + 41;
 132                 if (read_ref(name, new_sha1) < 0)
 133                         return error("no such local reference '%s'", name);
 134                 if (!has_sha1_file(old_sha1))
 135                         return error("remote '%s' points to object I don't have", name);
 136                 if (!memcmp(old_sha1, new_sha1, 20)) {
 137                         fprintf(stderr, "'%s' unchanged\n", name);
 138                         continue;
 139                 }
 140                 ref = xmalloc(sizeof(*ref) + len - 40);
 141                 memcpy(ref->old_sha1, old_sha1, 20);
 142                 memcpy(ref->new_sha1, new_sha1, 20);
 143                 memcpy(ref->name, buffer + 41, len - 40);
 144                 ref->next = NULL;
 145                 *last_ref = ref;
 146                 last_ref = &ref->next;
 147         }
 148
 149         for (ref = ref_list; ref; ref = ref->next) {
 150                 char old_hex[60], *new_hex;
 151                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 152                 new_hex = sha1_to_hex(ref->new_sha1);
 153                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 154                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 155         }
 156
 157         packet_flush(out);
 158         if (ref_list)
 159                 pack_objects(out, ref_list);
 160         close(out);
 161         return 0;
 162 }
 163
 164 /*
 165  * First, make it shell-safe.  We do this by just disallowing any
 166  * special characters. Somebody who cares can do escaping and let
 167  * through the rest. But since we're doing to feed this to ssh as
 168  * a command line, we're going to be pretty damn anal for now.
 169  */
 170 static char *shell_safe(char *url)
 171 {
 172         char *n = url;
 173         unsigned char c;
 174         static const char flags[256] = {
 175                 ['0'...'9'] = 1,
 176                 ['a'...'z'] = 1,
 177                 ['A'...'Z'] = 1,
 178                 ['.'] = 1, ['/'] = 1,
 179                 ['-'] = 1, ['+'] = 1,
 180                 [':'] = 1
 181         };
 182
 183         while ((c = *n++) != 0) {
 184                 if (flags[c] != 1)
 185                         die("I don't like '%c'. Sue me.", c);
 186         }
 187         return url;
 188 }
 189
 190 /*
 191  * Yeah, yeah, fixme. Need to pass in the heads etc.
 192  */
 193 static int setup_connection(int fd[2], char *url, char **heads)
 194 {
 195         char command[1024];
 196         const char *host, *path;
 197         char *colon;
 198         int pipefd[2][2];
 199         pid_t pid;
 200
 201         url = shell_safe(url);
 202         host = NULL;
 203         path = url;
 204         colon = strchr(url, ':');
 205         if (colon) {
 206                 *colon = 0;
 207                 host = url;
 208                 path = colon+1;
 209         }
 210         snprintf(command, sizeof(command), "%s %s", exec, path);
 211         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 212                 die("unable to create pipe pair for communication");
 213         pid = fork();
 214         if (!pid) {
 215                 dup2(pipefd[1][0], 0);
 216                 dup2(pipefd[0][1], 1);
 217                 close(pipefd[0][0]);
 218                 close(pipefd[0][1]);
 219                 close(pipefd[1][0]);
 220                 close(pipefd[1][1]);
 221                 if (host)
 222                         execlp("ssh", "ssh", host, command, NULL);
 223                 else
 224                         execlp("sh", "sh", "-c", command, NULL);
 225                 die("exec failed");
 226         }
 227         fd[0] = pipefd[0][0];
 228         fd[1] = pipefd[1][1];
 229         close(pipefd[0][1]);
 230         close(pipefd[1][0]);
 231         return pid;
 232 }
 233
 234 int main(int argc, char **argv)
 235 {
 236         int i, nr_heads = 0;
 237         char *dest = NULL;
 238         char **heads = NULL;
 239         int fd[2], ret;
 240         pid_t pid;
 241
 242         argv++;
 243         for (i = 1; i < argc; i++) {
 244                 char *arg = *argv++;
 245
 246                 if (*arg == '-') {
 247                         if (!strncmp(arg, "--exec=", 7)) {
 248                                 exec = arg + 7;
 249                                 continue;
 250                         }
 251                         usage(send_pack_usage);
 252                 }
 253                 dest = arg;
 254                 heads = argv;
 255                 nr_heads = argc - i -1;
 256                 break;
 257         }
 258         if (!dest)
 259                 usage(send_pack_usage);
 260         pid = setup_connection(fd, dest, heads);
 261         if (pid < 0)
 262                 return 1;
 263         ret = send_pack(fd[0], fd[1]);
 264         close(fd[0]);
 265         close(fd[1]);
 266         waitpid(pid, NULL, 0);
 267         return ret;
 268 }