Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "unix-socket.h"
   3
   4static int unix_stream_socket(void)
   5{
   6        int fd = socket(AF_UNIX, SOCK_STREAM, 0);
   7        if (fd < 0)
   8                die_errno("unable to create socket");
   9        return fd;
  10}
  11
  12static int chdir_len(const char *orig, int len)
  13{
  14        char *path = xmemdupz(orig, len);
  15        int r = chdir(path);
  16        free(path);
  17        return r;
  18}
  19
  20struct unix_sockaddr_context {
  21        char *orig_dir;
  22};
  23
  24static void unix_sockaddr_cleanup(struct unix_sockaddr_context *ctx)
  25{
  26        if (!ctx->orig_dir)
  27                return;
  28        /*
  29         * If we fail, we can't just return an error, since we have
  30         * moved the cwd of the whole process, which could confuse calling
  31         * code.  We are better off to just die.
  32         */
  33        if (chdir(ctx->orig_dir) < 0)
  34                die("unable to restore original working directory");
  35        free(ctx->orig_dir);
  36}
  37
  38static int unix_sockaddr_init(struct sockaddr_un *sa, const char *path,
  39                              struct unix_sockaddr_context *ctx)
  40{
  41        int size = strlen(path) + 1;
  42
  43        ctx->orig_dir = NULL;
  44        if (size > sizeof(sa->sun_path)) {
  45                const char *slash = find_last_dir_sep(path);
  46                const char *dir;
  47                struct strbuf cwd = STRBUF_INIT;
  48
  49                if (!slash) {
  50                        errno = ENAMETOOLONG;
  51                        return -1;
  52                }
  53
  54                dir = path;
  55                path = slash + 1;
  56                size = strlen(path) + 1;
  57                if (size > sizeof(sa->sun_path)) {
  58                        errno = ENAMETOOLONG;
  59                        return -1;
  60                }
  61                if (strbuf_getcwd(&cwd))
  62                        return -1;
  63                ctx->orig_dir = strbuf_detach(&cwd, NULL);
  64                if (chdir_len(dir, slash - dir) < 0)
  65                        return -1;
  66        }
  67
  68        memset(sa, 0, sizeof(*sa));
  69        sa->sun_family = AF_UNIX;
  70        memcpy(sa->sun_path, path, size);
  71        return 0;
  72}
  73
  74int unix_stream_connect(const char *path)
  75{
  76        int fd, saved_errno;
  77        struct sockaddr_un sa;
  78        struct unix_sockaddr_context ctx;
  79
  80        if (unix_sockaddr_init(&sa, path, &ctx) < 0)
  81                return -1;
  82        fd = unix_stream_socket();
  83        if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
  84                goto fail;
  85        unix_sockaddr_cleanup(&ctx);
  86        return fd;
  87
  88fail:
  89        saved_errno = errno;
  90        unix_sockaddr_cleanup(&ctx);
  91        close(fd);
  92        errno = saved_errno;
  93        return -1;
  94}
  95
  96int unix_stream_listen(const char *path)
  97{
  98        int fd, saved_errno;
  99        struct sockaddr_un sa;
 100        struct unix_sockaddr_context ctx;
 101
 102        unlink(path);
 103
 104        if (unix_sockaddr_init(&sa, path, &ctx) < 0)
 105                return -1;
 106        fd = unix_stream_socket();
 107
 108        if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
 109                goto fail;
 110
 111        if (listen(fd, 5) < 0)
 112                goto fail;
 113
 114        unix_sockaddr_cleanup(&ctx);
 115        return fd;
 116
 117fail:
 118        saved_errno = errno;
 119        unix_sockaddr_cleanup(&ctx);
 120        close(fd);
 121        errno = saved_errno;
 122        return -1;
 123}