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 [--inetd | --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(void)
  32 {
  33         static char line[1000];
  34         int len;
  35
  36         len = packet_read_line(0, line, sizeof(line));
  37
  38         if (len && line[len-1] == '\n')
  39                 line[--len] = 0;
  40
  41         if (!strncmp("git-upload-pack /", line, 17))
  42                 return upload(line + 16, len - 16);
  43
  44         fprintf(stderr, "got bad connection '%s'\n", line);
  45         return -1;
  46 }
  47
  48 static void handle(int incoming, struct sockaddr_in *addr, int addrlen)
  49 {
  50         if (fork()) {
  51                 close(incoming);
  52                 return;
  53         }
  54
  55         dup2(incoming, 0);
  56         dup2(incoming, 1);
  57         close(incoming);
  58         exit(execute());
  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 inetd_mode = 0;
 100         int i;
 101
 102         for (i = 1; i < argc; i++) {
 103                 char *arg = argv[i];
 104
 105                 if (!strncmp(arg, "--port=", 7)) {
 106                         char *end;
 107                         unsigned long n;
 108                         n = strtoul(arg+7, &end, 0);
 109                         if (arg[7] && !*end) {
 110                                 port = n;
 111                                 continue;
 112                         }
 113                 }
 114
 115                 if (!strcmp(arg, "--inetd")) {
 116                         inetd_mode = 1;
 117                         continue;
 118                 }
 119
 120                 usage(daemon_usage);
 121         }
 122
 123         if (inetd_mode)
 124                 return execute();
 125
 126         return serve(port);
 127 }