Blob


1 /*
2 * Copyright (c) 2023 Stefan Sperling <stsp@openbsd.org>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
17 /*
18 * Resolve path namespace conflicts for git-upload-pack and git-receive-pack.
19 */
21 #include <sys/queue.h>
22 #include <sys/types.h>
23 #include <sys/uio.h>
25 #include <err.h>
26 #include <errno.h>
27 #include <event.h>
28 #include <imsg.h>
29 #include <limits.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <sha1.h>
34 #include <sha2.h>
35 #include <syslog.h>
36 #include <util.h>
37 #include <unistd.h>
39 #include "got_error.h"
40 #include "got_path.h"
42 #include "got_lib_dial.h"
44 #include "gotd.h"
45 #include "log.h"
47 #ifndef GITWRAPPER_GIT_LIBEXEC_DIR
48 #define GITWRAPPER_GIT_LIBEXEC_DIR "/usr/local/libexec/git"
49 #endif
51 #ifndef GITWRAPPER_MY_SERVER_PROG
52 #define GITWRAPPER_MY_SERVER_PROG "gotsh"
53 #endif
56 __dead static void
57 usage(void)
58 {
59 fprintf(stderr, "usage: %s -c '%s|%s repository-path'\n",
60 getprogname(), GOT_DIAL_CMD_SEND, GOT_DIAL_CMD_FETCH);
61 exit(1);
62 }
64 /*
65 * Unveil the specific programs we want to start and hide everything else.
66 * This is important to limit the impact of our "exec" pledge.
67 */
68 static const struct got_error *
69 apply_unveil(const char *myserver)
70 {
71 const char *fetchcmd = GITWRAPPER_GIT_LIBEXEC_DIR "/" \
72 GOT_DIAL_CMD_FETCH;
73 const char *sendcmd = GITWRAPPER_GIT_LIBEXEC_DIR "/" \
74 GOT_DIAL_CMD_SEND;
76 #ifdef PROFILE
77 if (unveil("gmon.out", "rwc") != 0)
78 return got_error_from_errno2("unveil", "gmon.out");
79 #endif
80 if (unveil(fetchcmd, "x") != 0)
81 return got_error_from_errno2("unveil", fetchcmd);
83 if (unveil(sendcmd, "x") != 0)
84 return got_error_from_errno2("unveil", sendcmd);
86 if (myserver && unveil(myserver, "x") != 0)
87 return got_error_from_errno2("unveil", myserver);
89 if (unveil(NULL, NULL) != 0)
90 return got_error_from_errno("unveil");
92 return NULL;
93 }
95 int
96 main(int argc, char *argv[])
97 {
98 const struct got_error *error;
99 const char *confpath = NULL;
100 char *command = NULL, *repo_name = NULL; /* for matching gotd.conf */
101 char *myserver = NULL;
102 const char *repo_path = NULL; /* as passed on the command line */
103 const char *relpath;
104 char *gitcommand = NULL;
105 struct gotd gotd;
106 struct gotd_repo *repo = NULL;
108 log_init(1, LOG_USER); /* Log to stderr. */
110 #ifndef PROFILE
111 if (pledge("stdio rpath exec unveil", NULL) == -1)
112 err(1, "pledge");
113 #endif
115 /*
116 * Look up our own server program in PATH so we can unveil(2) it.
117 * This call only errors out upon memory allocation failure.
118 * If the program cannot be found then myserver will be set to NULL.
119 */
120 error = got_path_find_prog(&myserver, GITWRAPPER_MY_SERVER_PROG);
121 if (error)
122 goto done;
124 /*
125 * Run parse_config() before unveil(2) because parse_config()
126 * checks whether repository paths exist on disk.
127 * Parsing errors and warnings will be logged to stderr.
128 * Upon failure we will run Git's native tooling so do not
129 * bother checking for errors here.
130 */
131 confpath = getenv("GOTD_CONF_PATH");
132 if (confpath == NULL)
133 confpath = GOTD_CONF_PATH;
134 parse_config(confpath, PROC_GOTD, &gotd, 0);
136 error = apply_unveil(myserver);
137 if (error)
138 goto done;
140 #ifndef PROFILE
141 if (pledge("stdio exec", NULL) == -1)
142 err(1, "pledge");
143 #endif
145 if (strcmp(getprogname(), GOT_DIAL_CMD_SEND) == 0 ||
146 strcmp(getprogname(), GOT_DIAL_CMD_FETCH) == 0) {
147 if (argc != 2)
148 usage();
149 command = strdup(getprogname());
150 if (command == NULL) {
151 error = got_error_from_errno("strdup");
152 goto done;
154 repo_path = argv[1];
155 relpath = argv[1];
156 while (relpath[0] == '/')
157 relpath++;
158 repo_name = strdup(relpath);
159 if (repo_name == NULL) {
160 error = got_error_from_errno("strdup");
161 goto done;
163 } else {
164 if (argc != 3 || strcmp(argv[1], "-c") != 0)
165 usage();
166 repo_path = argv[2];
167 error = got_dial_parse_command(&command, &repo_name,
168 repo_path);
169 if (error && error->code == GOT_ERR_BAD_PACKET)
170 usage();
171 if (error)
172 goto done;
175 repo = gotd_find_repo_by_name(repo_name, &gotd);
177 /*
178 * Invoke our custom Git server if the repository was found
179 * in gotd.conf. Otherwise invoke native git(1) tooling.
180 */
181 if (repo) {
182 if (myserver == NULL) {
183 error = got_error_fmt(GOT_ERR_NO_PROG,
184 "cannot run '%s'",
185 GITWRAPPER_MY_SERVER_PROG);
186 goto done;
188 execl(myserver, command, repo_name, (char *)NULL);
189 error = got_error_from_errno2("execl", myserver);
190 } else {
191 if (asprintf(&gitcommand, "%s/%s",
192 GITWRAPPER_GIT_LIBEXEC_DIR, command) == -1) {
193 error = got_error_from_errno("asprintf");
194 goto done;
196 execl(gitcommand, gitcommand, repo_path, (char *)NULL);
197 error = got_error_from_errno2("execl", gitcommand);
200 done:
201 free(command);
202 free(repo_name);
203 free(myserver);
204 free(gitcommand);
205 if (error) {
206 fprintf(stderr, "%s: %s\n", getprogname(), error->msg);
207 return 1;
210 return 0;