send-pack.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3
   4 static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
   5
   6 static const char *exec = "git-receive-pack";
   7
   8 struct ref {
   9         struct ref *next;
  10         unsigned char old_sha1[20];
  11         unsigned char new_sha1[20];
  12         char name[0];
  13 };
  14
  15 static struct ref *ref_list = NULL;
  16
  17 static int read_ref(const char *ref, unsigned char *sha1)
  18 {
  19         int fd, ret;
  20         static char pathname[PATH_MAX];
  21         char buffer[60];
  22         const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
  23
  24         snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, ref);
  25         fd = open(pathname, O_RDONLY);
  26         if (fd < 0)
  27                 return -1;
  28         ret = -1;
  29         if (read(fd, buffer, sizeof(buffer)) >= 40)
  30                 ret = get_sha1_hex(buffer, sha1);
  31         close(fd);
  32         return ret;
  33 }
  34
  35 static int send_pack(int in, int out)
  36 {
  37         for (;;) {
  38                 unsigned char old_sha1[20];
  39                 unsigned char new_sha1[20];
  40                 static char buffer[1000];
  41                 char *name;
  42                 struct ref *n;
  43                 int len;
  44
  45                 len = packet_read_line(in, buffer, sizeof(buffer));
  46                 if (!len)
  47                         break;
  48                 if (buffer[len-1] == '\n')
  49                         buffer[--len] = 0;
  50
  51                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  52                         die("protocol error: expected sha/ref, got '%s'", buffer);
  53                 name = buffer + 41;
  54                 if (read_ref(name, new_sha1) < 0) {
  55                         fprintf(stderr, "no such local reference '%s'\n", name);
  56                         continue;
  57                 }
  58                 if (!has_sha1_file(old_sha1)) {
  59                         fprintf(stderr, "remote '%s' points to object I don't have\n", name);
  60                         continue;
  61                 }
  62                 if (!memcmp(old_sha1, new_sha1, 20)) {
  63                         fprintf(stderr, "'%s' unchanged\n", name);
  64                 } else {
  65                         char new_hex[60];
  66                         strcpy(new_hex, sha1_to_hex(new_sha1));
  67                         fprintf(stderr, "%s: updating from %s to %s\n", name, sha1_to_hex(old_sha1), new_hex);
  68                 }
  69                 n = xmalloc(sizeof(*n) + len - 40);
  70                 memcpy(n->old_sha1, old_sha1, 20);
  71                 memcpy(n->new_sha1, new_sha1, 20);
  72                 memcpy(n->name, buffer + 41, len - 40);
  73                 n->next = ref_list;
  74                 ref_list = n;
  75         }
  76         packet_flush(out);
  77         close(out);
  78         return 0;
  79 }
  80
  81 /*
  82  * First, make it shell-safe.  We do this by just disallowing any
  83  * special characters. Somebody who cares can do escaping and let
  84  * through the rest. But since we're doing to feed this to ssh as
  85  * a command line, we're going to be pretty damn anal for now.
  86  */
  87 static char *shell_safe(char *url)
  88 {
  89         char *n = url;
  90         unsigned char c;
  91         static const char flags[256] = {
  92                 ['0'...'9'] = 1,
  93                 ['a'...'z'] = 1,
  94                 ['A'...'Z'] = 1,
  95                 ['.'] = 1, ['/'] = 1,
  96                 ['-'] = 1, ['+'] = 1,
  97                 [':'] = 1
  98         };
  99
 100         while ((c = *n++) != 0) {
 101                 if (flags[c] != 1)
 102                         die("I don't like '%c'. Sue me.", c);
 103         }
 104         return url;
 105 }
 106
 107 /*
 108  * Yeah, yeah, fixme. Need to pass in the heads etc.
 109  */
 110 static int setup_connection(int fd[2], char *url, char **heads)
 111 {
 112         char command[1024];
 113         const char *host, *path;
 114         char *colon;
 115         int pipefd[2][2];
 116
 117         url = shell_safe(url);
 118         host = NULL;
 119         path = url;
 120         colon = strchr(url, ':');
 121         if (colon) {
 122                 *colon = 0;
 123                 host = url;
 124                 path = colon+1;
 125         }
 126         snprintf(command, sizeof(command), "%s %s", exec, path);
 127         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 128                 die("unable to create pipe pair for communication");
 129         if (!fork()) {
 130                 dup2(pipefd[1][0], 0);
 131                 dup2(pipefd[0][1], 1);
 132                 close(pipefd[0][0]);
 133                 close(pipefd[0][1]);
 134                 close(pipefd[1][0]);
 135                 close(pipefd[1][1]);
 136                 if (host)
 137                         execlp("ssh", "ssh", host, command, NULL);
 138                 else
 139                         execlp("sh", "sh", "-c", command, NULL);
 140                 die("exec failed");
 141         }
 142         fd[0] = pipefd[0][0];
 143         fd[1] = pipefd[1][1];
 144         close(pipefd[0][1]);
 145         close(pipefd[1][0]);
 146         return 0;
 147 }
 148
 149 int main(int argc, char **argv)
 150 {
 151         int i, nr_heads = 0;
 152         char *dest = NULL;
 153         char **heads = NULL;
 154         int fd[2];
 155
 156         argv++;
 157         for (i = 1; i < argc; i++) {
 158                 char *arg = *argv++;
 159
 160                 if (*arg == '-') {
 161                         if (!strncmp(arg, "--exec=", 7)) {
 162                                 exec = arg + 7;
 163                                 continue;
 164                         }
 165                         usage(send_pack_usage);
 166                 }
 167                 dest = arg;
 168                 heads = argv;
 169                 nr_heads = argc - i -1;
 170                 break;
 171         }
 172         if (!dest)
 173                 usage(send_pack_usage);
 174         if (setup_connection(fd, dest, heads))
 175                 return 1;
 176         return send_pack(fd[0], fd[1]);
 177 }