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 static const char *exec = "git-receive-pack";
   7
   8 static int path_match(const char *path, int nr, char **match)
   9 {
  10         int i;
  11         int pathlen = strlen(path);
  12
  13         for (i = 0; i < nr; i++) {
  14                 char *s = match[i];
  15                 int len = strlen(s);
  16
  17                 if (!len || len > pathlen)
  18                         continue;
  19                 if (memcmp(path + pathlen - len, s, len))
  20                         continue;
  21                 if (pathlen > len && path[pathlen - len - 1] != '/')
  22                         continue;
  23                 *s = 0;
  24                 return 1;
  25         }
  26         return 0;
  27 }
  28
  29 struct ref {
  30         struct ref *next;
  31         unsigned char old_sha1[20];
  32         unsigned char new_sha1[20];
  33         char name[0];
  34 };
  35
  36 static void exec_pack_objects(void)
  37 {
  38         static char *args[] = {
  39                 "git-pack-objects",
  40                 "--stdout",
  41                 NULL
  42         };
  43         execvp("git-pack-objects", args);
  44         die("git-pack-objects exec failed (%s)", strerror(errno));
  45 }
  46
  47 static void exec_rev_list(struct ref *refs)
  48 {
  49         static char *args[1000];
  50         int i = 0;
  51
  52         args[i++] = "git-rev-list";     /* 0 */
  53         args[i++] = "--objects";        /* 1 */
  54         while (refs) {
  55                 char *buf = malloc(100);
  56                 if (i > 900)
  57                         die("git-rev-list environment overflow");
  58                 args[i++] = buf;
  59                 snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  60                 buf += 50;
  61                 args[i++] = buf;
  62                 snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  63                 refs = refs->next;
  64         }
  65         args[i] = NULL;
  66         execvp("git-rev-list", args);
  67         die("git-rev-list exec failed (%s)", strerror(errno));
  68 }
  69
  70 static void rev_list(int fd, struct ref *refs)
  71 {
  72         int pipe_fd[2];
  73         pid_t pack_objects_pid;
  74
  75         if (pipe(pipe_fd) < 0)
  76                 die("rev-list setup: pipe failed");
  77         pack_objects_pid = fork();
  78         if (!pack_objects_pid) {
  79                 dup2(pipe_fd[0], 0);
  80                 dup2(fd, 1);
  81                 close(pipe_fd[0]);
  82                 close(pipe_fd[1]);
  83                 close(fd);
  84                 exec_pack_objects();
  85                 die("pack-objects setup failed");
  86         }
  87         if (pack_objects_pid < 0)
  88                 die("pack-objects fork failed");
  89         dup2(pipe_fd[1], 1);
  90         close(pipe_fd[0]);
  91         close(pipe_fd[1]);
  92         close(fd);
  93         exec_rev_list(refs);
  94 }
  95
  96 static int pack_objects(int fd, struct ref *refs)
  97 {
  98         pid_t rev_list_pid;
  99
 100         rev_list_pid = fork();
 101         if (!rev_list_pid) {
 102                 rev_list(fd, refs);
 103                 die("rev-list setup failed");
 104         }
 105         if (rev_list_pid < 0)
 106                 die("rev-list fork failed");
 107         /*
 108          * We don't wait for the rev-list pipeline in the parent:
 109          * we end up waiting for the other end instead
 110          */
 111 }
 112
 113 static int read_ref(const char *ref, unsigned char *sha1)
 114 {
 115         int fd, ret;
 116         static char pathname[PATH_MAX];
 117         char buffer[60];
 118         const char *git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
 119
 120         snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, ref);
 121         fd = open(pathname, O_RDONLY);
 122         if (fd < 0)
 123                 return -1;
 124         ret = -1;
 125         if (read(fd, buffer, sizeof(buffer)) >= 40)
 126                 ret = get_sha1_hex(buffer, sha1);
 127         close(fd);
 128         return ret;
 129 }
 130
 131 static int send_pack(int in, int out, int nr_match, char **match)
 132 {
 133         struct ref *ref_list = NULL, **last_ref = &ref_list;
 134         struct ref *ref;
 135
 136         for (;;) {
 137                 unsigned char old_sha1[20];
 138                 unsigned char new_sha1[20];
 139                 static char buffer[1000];
 140                 char *name;
 141                 int len;
 142
 143                 len = packet_read_line(in, buffer, sizeof(buffer));
 144                 if (!len)
 145                         break;
 146                 if (buffer[len-1] == '\n')
 147                         buffer[--len] = 0;
 148
 149                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 150                         die("protocol error: expected sha/ref, got '%s'", buffer);
 151                 name = buffer + 41;
 152                 if (nr_match && !path_match(name, nr_match, match))
 153                         continue;
 154                 if (read_ref(name, new_sha1) < 0)
 155                         return error("no such local reference '%s'", name);
 156                 if (!has_sha1_file(old_sha1))
 157                         return error("remote '%s' points to object I don't have", name);
 158                 if (!memcmp(old_sha1, new_sha1, 20)) {
 159                         fprintf(stderr, "'%s' unchanged\n", name);
 160                         continue;
 161                 }
 162                 ref = xmalloc(sizeof(*ref) + len - 40);
 163                 memcpy(ref->old_sha1, old_sha1, 20);
 164                 memcpy(ref->new_sha1, new_sha1, 20);
 165                 memcpy(ref->name, buffer + 41, len - 40);
 166                 ref->next = NULL;
 167                 *last_ref = ref;
 168                 last_ref = &ref->next;
 169         }
 170
 171         for (ref = ref_list; ref; ref = ref->next) {
 172                 char old_hex[60], *new_hex;
 173                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 174                 new_hex = sha1_to_hex(ref->new_sha1);
 175                 packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 176                 fprintf(stderr, "'%s': updating from %s to %s\n", ref->name, old_hex, new_hex);
 177         }
 178
 179         packet_flush(out);
 180         if (ref_list)
 181                 pack_objects(out, ref_list);
 182         close(out);
 183         return 0;
 184 }
 185
 186 /*
 187  * First, make it shell-safe.  We do this by just disallowing any
 188  * special characters. Somebody who cares can do escaping and let
 189  * through the rest. But since we're doing to feed this to ssh as
 190  * a command line, we're going to be pretty damn anal for now.
 191  */
 192 static char *shell_safe(char *url)
 193 {
 194         char *n = url;
 195         unsigned char c;
 196         static const char flags[256] = {
 197                 ['0'...'9'] = 1,
 198                 ['a'...'z'] = 1,
 199                 ['A'...'Z'] = 1,
 200                 ['.'] = 1, ['/'] = 1,
 201                 ['-'] = 1, ['+'] = 1,
 202                 [':'] = 1
 203         };
 204
 205         while ((c = *n++) != 0) {
 206                 if (flags[c] != 1)
 207                         die("I don't like '%c'. Sue me.", c);
 208         }
 209         return url;
 210 }
 211
 212 /*
 213  * Yeah, yeah, fixme. Need to pass in the heads etc.
 214  */
 215 static int setup_connection(int fd[2], char *url, char **heads)
 216 {
 217         char command[1024];
 218         const char *host, *path;
 219         char *colon;
 220         int pipefd[2][2];
 221         pid_t pid;
 222
 223         url = shell_safe(url);
 224         host = NULL;
 225         path = url;
 226         colon = strchr(url, ':');
 227         if (colon) {
 228                 *colon = 0;
 229                 host = url;
 230                 path = colon+1;
 231         }
 232         snprintf(command, sizeof(command), "%s %s", exec, path);
 233         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 234                 die("unable to create pipe pair for communication");
 235         pid = fork();
 236         if (!pid) {
 237                 dup2(pipefd[1][0], 0);
 238                 dup2(pipefd[0][1], 1);
 239                 close(pipefd[0][0]);
 240                 close(pipefd[0][1]);
 241                 close(pipefd[1][0]);
 242                 close(pipefd[1][1]);
 243                 if (host)
 244                         execlp("ssh", "ssh", host, command, NULL);
 245                 else
 246                         execlp("sh", "sh", "-c", command, NULL);
 247                 die("exec failed");
 248         }
 249         fd[0] = pipefd[0][0];
 250         fd[1] = pipefd[1][1];
 251         close(pipefd[0][1]);
 252         close(pipefd[1][0]);
 253         return pid;
 254 }
 255
 256 int main(int argc, char **argv)
 257 {
 258         int i, nr_heads = 0;
 259         char *dest = NULL;
 260         char **heads = NULL;
 261         int fd[2], ret;
 262         pid_t pid;
 263
 264         argv++;
 265         for (i = 1; i < argc; i++) {
 266                 char *arg = *argv++;
 267
 268                 if (*arg == '-') {
 269                         if (!strncmp(arg, "--exec=", 7)) {
 270                                 exec = arg + 7;
 271                                 continue;
 272                         }
 273                         usage(send_pack_usage);
 274                 }
 275                 dest = arg;
 276                 heads = argv;
 277                 nr_heads = argc - i -1;
 278                 break;
 279         }
 280         if (!dest)
 281                 usage(send_pack_usage);
 282         pid = setup_connection(fd, dest, heads);
 283         if (pid < 0)
 284                 return 1;
 285         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 286         close(fd[0]);
 287         close(fd[1]);
 288         waitpid(pid, NULL, 0);
 289         return ret;
 290 }