daemon.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include <sys/socket.h>
   4 #include <netinet/in.h>
   5
   6 static const char daemon_usage[] = "git-daemon [--port=n]";
   7
   8 static int upload(char *dir, int dirlen)
   9 {
  10         if (chdir(dir) < 0)
  11                 return -1;
  12         chdir(".git");
  13
  14         /*
  15          * Security on the cheap.
  16          *
  17          * We want a readable HEAD, usable "objects" directory, and
  18          * a "git-daemon-export-ok" flag that says that the other side
  19          * is ok with us doing this.
  20          */
  21         if (access("git-daemon-export-ok", F_OK) ||
  22             access("objects/00", X_OK) ||
  23             access("HEAD", R_OK))
  24                 return -1;
  25
  26         /* git-upload-pack only ever reads stuff, so this is safe */
  27         execlp("git-upload-pack", "git-upload-pack", ".", NULL);
  28         return -1;
  29 }
  30
  31 static int execute(char *line, int len)
  32 {
  33         if (!strncmp("git-upload-pack /", line, 17))
  34                 return upload(line + 16, len - 16);
  35
  36         fprintf(stderr, "got bad connection '%s'\n", line);
  37         return -1;
  38 }
  39
  40 static void handle(int incoming, struct sockaddr_in *addr, int addrlen)
  41 {
  42         static char line[1000];
  43         int len;
  44
  45         if (fork()) {
  46                 close(incoming);
  47                 return;
  48         }
  49
  50         dup2(incoming, 0);
  51         dup2(incoming, 1);
  52         close(incoming);
  53         len = packet_read_line(0, line, sizeof(line));
  54
  55         if (len && line[len-1] == '\n')
  56                 line[--len] = 0;
  57
  58         exit(execute(line, len));
  59 }
  60
  61 static int serve(int port)
  62 {
  63         int sockfd;
  64         struct sockaddr_in addr;
  65
  66         sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_IP);
  67         if (sockfd < 0)
  68                 die("unable to open socket (%s)", strerror(errno));
  69         memset(&addr, 0, sizeof(addr));
  70         addr.sin_port = htons(port);
  71         addr.sin_family = AF_INET;
  72         if (bind(sockfd, (void *)&addr, sizeof(addr)) < 0)
  73                 die("unable to bind to port %d (%s)", port, strerror(errno));
  74         if (listen(sockfd, 5) < 0)
  75                 die("unable to listen to port %d (%s)", port, strerror(errno));
  76
  77         for (;;) {
  78                 struct sockaddr_in in;
  79                 socklen_t addrlen = sizeof(in);
  80                 int incoming = accept(sockfd, (void *)&in, &addrlen);
  81
  82                 if (incoming < 0) {
  83                         switch (errno) {
  84                         case EAGAIN:
  85                         case EINTR:
  86                         case ECONNABORTED:
  87                                 continue;
  88                         default:
  89                                 die("accept returned %s", strerror(errno));
  90                         }
  91                 }
  92                 handle(incoming, &in, addrlen);
  93         }
  94 }
  95
  96 int main(int argc, char **argv)
  97 {
  98         int port = DEFAULT_GIT_PORT;
  99         int i;
 100
 101         for (i = 1; i < argc; i++) {
 102                 char *arg = argv[i];
 103
 104                 if (!strncmp(arg, "--port=", 7)) {
 105                         char *end;
 106                         unsigned long n;
 107                         n = strtoul(arg+7, &end, 0);
 108                         if (arg[7] && !*end) {
 109                                 port = n;
 110                                 continue;
 111                         }
 112                 }
 113                 usage(daemon_usage);
 114         }
 115
 116         return serve(port);
 117 }