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 struct ref *ref_list = NULL, **last_ref = &ref_list;
  17
  18 static int read_ref(const char *ref, unsigned char *sha1)
  19 {
  20         int fd, ret;
  21         static char pathname[PATH_MAX];
  22         char buffer[60];
  23         const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
  24
  25         snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, ref);
  26         fd = open(pathname, O_RDONLY);
  27         if (fd < 0)
  28                 return -1;
  29         ret = -1;
  30         if (read(fd, buffer, sizeof(buffer)) >= 40)
  31                 ret = get_sha1_hex(buffer, sha1);
  32         close(fd);
  33         return ret;
  34 }
  35
  36 static int send_pack(int in, int out)
  37 {
  38         struct ref *ref;
  39
  40         for (;;) {
  41                 unsigned char old_sha1[20];
  42                 unsigned char new_sha1[20];
  43                 static char buffer[1000];
  44                 char *name;
  45                 int len;
  46
  47                 len = packet_read_line(in, buffer, sizeof(buffer));
  48                 if (!len)
  49                         break;
  50                 if (buffer[len-1] == '\n')
  51                         buffer[--len] = 0;
  52
  53                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  54                         die("protocol error: expected sha/ref, got '%s'", buffer);
  55                 name = buffer + 41;
  56                 if (read_ref(name, new_sha1) < 0)
  57                         return error("no such local reference '%s'", name);
  58                 if (!has_sha1_file(old_sha1))
  59                         return error("remote '%s' points to object I don't have", name);
  60                 if (!memcmp(old_sha1, new_sha1, 20)) {
  61                         fprintf(stderr, "'%s' unchanged\n", name);
  62                         continue;
  63                 }
  64                 ref = xmalloc(sizeof(*ref) + len - 40);
  65                 memcpy(ref->old_sha1, old_sha1, 20);
  66                 memcpy(ref->new_sha1, new_sha1, 20);
  67                 memcpy(ref->name, buffer + 41, len - 40);
  68                 ref->next = NULL;
  69                 *last_ref = ref;
  70                 last_ref = &ref->next;
  71         }
  72
  73         for (ref = ref_list; ref; ref = ref->next) {
  74                 char old_hex[60], *new_hex;
  75                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
  76                 new_hex = sha1_to_hex(ref->new_sha1);
  77                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
  78                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
  79         }
  80
  81         packet_flush(out);
  82         close(out);
  83         return 0;
  84 }
  85
  86 /*
  87  * First, make it shell-safe.  We do this by just disallowing any
  88  * special characters. Somebody who cares can do escaping and let
  89  * through the rest. But since we're doing to feed this to ssh as
  90  * a command line, we're going to be pretty damn anal for now.
  91  */
  92 static char *shell_safe(char *url)
  93 {
  94         char *n = url;
  95         unsigned char c;
  96         static const char flags[256] = {
  97                 ['0'...'9'] = 1,
  98                 ['a'...'z'] = 1,
  99                 ['A'...'Z'] = 1,
 100                 ['.'] = 1, ['/'] = 1,
 101                 ['-'] = 1, ['+'] = 1,
 102                 [':'] = 1
 103         };
 104
 105         while ((c = *n++) != 0) {
 106                 if (flags[c] != 1)
 107                         die("I don't like '%c'. Sue me.", c);
 108         }
 109         return url;
 110 }
 111
 112 /*
 113  * Yeah, yeah, fixme. Need to pass in the heads etc.
 114  */
 115 static int setup_connection(int fd[2], char *url, char **heads)
 116 {
 117         char command[1024];
 118         const char *host, *path;
 119         char *colon;
 120         int pipefd[2][2];
 121         pid_t pid;
 122
 123         url = shell_safe(url);
 124         host = NULL;
 125         path = url;
 126         colon = strchr(url, ':');
 127         if (colon) {
 128                 *colon = 0;
 129                 host = url;
 130                 path = colon+1;
 131         }
 132         snprintf(command, sizeof(command), "%s %s", exec, path);
 133         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 134                 die("unable to create pipe pair for communication");
 135         pid = fork();
 136         if (!pid) {
 137                 dup2(pipefd[1][0], 0);
 138                 dup2(pipefd[0][1], 1);
 139                 close(pipefd[0][0]);
 140                 close(pipefd[0][1]);
 141                 close(pipefd[1][0]);
 142                 close(pipefd[1][1]);
 143                 if (host)
 144                         execlp("ssh", "ssh", host, command, NULL);
 145                 else
 146                         execlp("sh", "sh", "-c", command, NULL);
 147                 die("exec failed");
 148         }
 149         fd[0] = pipefd[0][0];
 150         fd[1] = pipefd[1][1];
 151         close(pipefd[0][1]);
 152         close(pipefd[1][0]);
 153         return pid;
 154 }
 155
 156 int main(int argc, char **argv)
 157 {
 158         int i, nr_heads = 0;
 159         char *dest = NULL;
 160         char **heads = NULL;
 161         int fd[2], ret;
 162         pid_t pid;
 163
 164         argv++;
 165         for (i = 1; i < argc; i++) {
 166                 char *arg = *argv++;
 167
 168                 if (*arg == '-') {
 169                         if (!strncmp(arg, "--exec=", 7)) {
 170                                 exec = arg + 7;
 171                                 continue;
 172                         }
 173                         usage(send_pack_usage);
 174                 }
 175                 dest = arg;
 176                 heads = argv;
 177                 nr_heads = argc - i -1;
 178                 break;
 179         }
 180         if (!dest)
 181                 usage(send_pack_usage);
 182         pid = setup_connection(fd, dest, heads);
 183         if (pid < 0)
 184                 return 1;
 185         ret = send_pack(fd[0], fd[1]);
 186         close(fd[0]);
 187         close(fd[1]);
 188         waitpid(pid, NULL, 0);
 189         return ret;
 190 }