builtin/clone: allow remote helpers to detect repo
[alt-git.git] / unix-socket.c
blob79800d80636fc57fa8cc2696e33013c1c29e86b3
1 #include "git-compat-util.h"
2 #include "strbuf.h"
3 #include "unix-socket.h"
5 #define DEFAULT_UNIX_STREAM_LISTEN_BACKLOG (5)
7 static int chdir_len(const char *orig, int len)
9 char *path = xmemdupz(orig, len);
10 int r = chdir(path);
11 free(path);
12 return r;
15 struct unix_sockaddr_context {
16 char *orig_dir;
19 static void unix_sockaddr_cleanup(struct unix_sockaddr_context *ctx)
21 if (!ctx->orig_dir)
22 return;
24 * If we fail, we can't just return an error, since we have
25 * moved the cwd of the whole process, which could confuse calling
26 * code. We are better off to just die.
28 if (chdir(ctx->orig_dir) < 0)
29 die("unable to restore original working directory");
30 free(ctx->orig_dir);
33 static int unix_sockaddr_init(struct sockaddr_un *sa, const char *path,
34 struct unix_sockaddr_context *ctx,
35 int disallow_chdir)
37 int size = strlen(path) + 1;
39 ctx->orig_dir = NULL;
40 if (size > sizeof(sa->sun_path)) {
41 const char *slash;
42 const char *dir;
43 struct strbuf cwd = STRBUF_INIT;
45 if (disallow_chdir) {
46 errno = ENAMETOOLONG;
47 return -1;
50 slash = find_last_dir_sep(path);
51 if (!slash) {
52 errno = ENAMETOOLONG;
53 return -1;
56 dir = path;
57 path = slash + 1;
58 size = strlen(path) + 1;
59 if (size > sizeof(sa->sun_path)) {
60 errno = ENAMETOOLONG;
61 return -1;
63 if (strbuf_getcwd(&cwd))
64 return -1;
65 ctx->orig_dir = strbuf_detach(&cwd, NULL);
66 if (chdir_len(dir, slash - dir) < 0)
67 return -1;
70 memset(sa, 0, sizeof(*sa));
71 sa->sun_family = AF_UNIX;
72 memcpy(sa->sun_path, path, size);
73 return 0;
76 int unix_stream_connect(const char *path, int disallow_chdir)
78 int fd = -1, saved_errno;
79 struct sockaddr_un sa;
80 struct unix_sockaddr_context ctx;
82 if (unix_sockaddr_init(&sa, path, &ctx, disallow_chdir) < 0)
83 return -1;
84 fd = socket(AF_UNIX, SOCK_STREAM, 0);
85 if (fd < 0)
86 goto fail;
88 if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
89 goto fail;
90 unix_sockaddr_cleanup(&ctx);
91 return fd;
93 fail:
94 saved_errno = errno;
95 if (fd != -1)
96 close(fd);
97 unix_sockaddr_cleanup(&ctx);
98 errno = saved_errno;
99 return -1;
102 int unix_stream_listen(const char *path,
103 const struct unix_stream_listen_opts *opts)
105 int fd = -1, saved_errno;
106 int backlog;
107 struct sockaddr_un sa;
108 struct unix_sockaddr_context ctx;
110 unlink(path);
112 if (unix_sockaddr_init(&sa, path, &ctx, opts->disallow_chdir) < 0)
113 return -1;
114 fd = socket(AF_UNIX, SOCK_STREAM, 0);
115 if (fd < 0)
116 goto fail;
118 if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0)
119 goto fail;
121 backlog = opts->listen_backlog_size;
122 if (backlog <= 0)
123 backlog = DEFAULT_UNIX_STREAM_LISTEN_BACKLOG;
124 if (listen(fd, backlog) < 0)
125 goto fail;
127 unix_sockaddr_cleanup(&ctx);
128 return fd;
130 fail:
131 saved_errno = errno;
132 if (fd != -1)
133 close(fd);
134 unix_sockaddr_cleanup(&ctx);
135 errno = saved_errno;
136 return -1;