2 * Copyright (c) 2018, 2019 Ori Bernstein <ori@openbsd.org>
3 * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 #include "got_compat.h"
20 #include <sys/queue.h>
21 #include <sys/types.h>
22 #include <sys/socket.h>
33 #include "got_error.h"
36 #include "got_compat.h"
38 #include "got_lib_dial.h"
42 #define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
46 #define ssizeof(_x) ((ssize_t)(sizeof(_x)))
50 #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
53 #ifndef GOT_DIAL_PATH_SSH
54 #define GOT_DIAL_PATH_SSH "/usr/bin/ssh"
58 #define GOT_DEFAULT_GIT_PORT 9418
59 #define GOT_DEFAULT_GIT_PORT_STR "9418"
61 const struct got_error *
62 got_dial_apply_unveil(const char *proto)
64 if (strcmp(proto, "git+ssh") == 0 || strcmp(proto, "ssh") == 0) {
65 if (unveil(GOT_DIAL_PATH_SSH, "x") != 0) {
66 return got_error_from_errno2("unveil",
75 hassuffix(const char *base, const char *suf)
81 if (ns <= nb && strcmp(base + (nb - ns), suf) == 0)
86 const struct got_error *
87 got_dial_parse_uri(char **proto, char **host, char **port,
88 char **server_path, char **repo_name, const char *uri)
90 const struct got_error *err = NULL;
93 *proto = *host = *port = *server_path = *repo_name = NULL;
95 p = strstr(uri, "://");
97 /* Try parsing Git's "scp" style URL syntax. */
98 *proto = strdup("ssh");
100 err = got_error_from_errno("strdup");
106 err = got_error(GOT_ERR_PARSE_URI);
109 /* No slashes allowed before first colon. */
112 err = got_error(GOT_ERR_PARSE_URI);
115 *host = strndup(s, q - s);
117 err = got_error_from_errno("strndup");
120 if ((*host)[0] == '\0') {
121 err = got_error(GOT_ERR_PARSE_URI);
126 *proto = strndup(uri, p - uri);
127 if (*proto == NULL) {
128 err = got_error_from_errno("strndup");
134 if (p == NULL || strlen(p) == 1) {
135 err = got_error(GOT_ERR_PARSE_URI);
139 q = memchr(s, ':', p - s);
141 *host = strndup(s, q - s);
143 err = got_error_from_errno("strndup");
146 if ((*host)[0] == '\0') {
147 err = got_error(GOT_ERR_PARSE_URI);
150 *port = strndup(q + 1, p - (q + 1));
152 err = got_error_from_errno("strndup");
155 if ((*port)[0] == '\0') {
156 err = got_error(GOT_ERR_PARSE_URI);
160 *host = strndup(s, p - s);
162 err = got_error_from_errno("strndup");
165 if ((*host)[0] == '\0') {
166 err = got_error(GOT_ERR_PARSE_URI);
172 while (p[0] == '/' && p[1] == '/')
174 *server_path = strdup(p);
175 if (*server_path == NULL) {
176 err = got_error_from_errno("strdup");
179 got_path_strip_trailing_slashes(*server_path);
180 if ((*server_path)[0] == '\0') {
181 err = got_error(GOT_ERR_PARSE_URI);
185 err = got_path_basename(repo_name, *server_path);
188 if (hassuffix(*repo_name, ".git"))
189 (*repo_name)[strlen(*repo_name) - 4] = '\0';
190 if ((*repo_name)[0] == '\0')
191 err = got_error(GOT_ERR_PARSE_URI);
209 * Escape a given path for the shell which will be started by sshd.
210 * In particular, git-shell is known to require single-quote characters
211 * around its repository path argument and will refuse to run otherwise.
213 static const struct got_error *
214 escape_path(char *buf, size_t bufsize, const char *path)
225 while (*p != '\0' && (q - buf < bufsize)) {
226 /* git escapes ! too */
227 if (*p != '\'' && *p != '!') {
232 if (q - buf + 4 >= bufsize)
240 if (*p == '\0' && (q - buf + 1 < bufsize)) {
246 return got_error_fmt(GOT_ERR_NO_SPACE, "overlong path: %s", path);
249 const struct got_error *
250 got_dial_ssh(pid_t *newpid, int *newfd, const char *host,
251 const char *port, const char *path, const char *command, int verbosity)
253 const struct got_error *error = NULL;
256 char escaped_path[PATH_MAX];
257 const char *argv[11];
263 error = escape_path(escaped_path, sizeof(escaped_path), path);
267 argv[i++] = GOT_DIAL_PATH_SSH;
270 argv[i++] = (char *)port;
272 if (verbosity == -1) {
275 /* ssh(1) allows up to 3 "-v" options. */
276 for (j = 0; j < MIN(3, verbosity); j++)
280 argv[i++] = (char *)host;
281 argv[i++] = (char *)cmd;
282 argv[i++] = (char *)escaped_path;
284 assert(i <= nitems(argv));
286 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pfd) == -1)
287 return got_error_from_errno("socketpair");
291 error = got_error_from_errno("fork");
295 } else if (pid == 0) {
296 if (close(pfd[1]) == -1)
298 if (dup2(pfd[0], 0) == -1)
300 if (dup2(pfd[0], 1) == -1)
302 if (strlcpy(cmd, command, sizeof(cmd)) >= sizeof(cmd))
304 if (execv(GOT_DIAL_PATH_SSH, (char *const *)argv) == -1)
306 abort(); /* not reached */
308 if (close(pfd[0]) == -1)
309 return got_error_from_errno("close");
316 const struct got_error *
317 got_dial_git(int *newfd, const char *host, const char *port,
318 const char *path, const char *command)
320 const struct got_error *err = NULL;
321 struct addrinfo hints, *servinfo, *p;
323 int fd = -1, len, r, eaicode;
328 port = GOT_DEFAULT_GIT_PORT_STR;
330 memset(&hints, 0, sizeof hints);
331 hints.ai_family = AF_UNSPEC;
332 hints.ai_socktype = SOCK_STREAM;
333 eaicode = getaddrinfo(host, port, &hints, &servinfo);
336 snprintf(msg, sizeof(msg), "%s: %s", host,
337 gai_strerror(eaicode));
338 return got_error_msg(GOT_ERR_ADDRINFO, msg);
341 for (p = servinfo; p != NULL; p = p->ai_next) {
342 if ((fd = socket(p->ai_family, p->ai_socktype,
343 p->ai_protocol)) == -1)
345 if (connect(fd, p->ai_addr, p->ai_addrlen) == 0) {
349 err = got_error_from_errno("connect");
352 freeaddrinfo(servinfo);
356 if (asprintf(&cmd, "%s %s", command, path) == -1) {
357 err = got_error_from_errno("asprintf");
360 len = 4 + strlen(cmd) + 1 + strlen("host=") + strlen(host) + 1;
361 r = dprintf(fd, "%04x%s%chost=%s%c", len, cmd, '\0', host, '\0');
363 err = got_error_from_errno("dprintf");
374 const struct got_error *
375 got_dial_parse_command(char **command, char **repo_path, const char *gitcmd)
377 const struct got_error *err = NULL;
378 size_t len, cmdlen, pathlen;
379 char *path0 = NULL, *path, *abspath = NULL, *canonpath = NULL;
385 len = strlen(gitcmd);
387 if (len >= strlen(GOT_DIAL_CMD_SEND) &&
388 strncmp(gitcmd, GOT_DIAL_CMD_SEND,
389 strlen(GOT_DIAL_CMD_SEND)) == 0)
390 cmdlen = strlen(GOT_DIAL_CMD_SEND);
391 else if (len >= strlen(GOT_DIAL_CMD_FETCH) &&
392 strncmp(gitcmd, GOT_DIAL_CMD_FETCH,
393 strlen(GOT_DIAL_CMD_FETCH)) == 0)
394 cmdlen = strlen(GOT_DIAL_CMD_FETCH);
396 return got_error(GOT_ERR_BAD_PACKET);
398 if (len <= cmdlen + 1 || gitcmd[cmdlen] != ' ')
399 return got_error(GOT_ERR_BAD_PACKET);
401 if (memchr(&gitcmd[cmdlen + 1], '\0', len - cmdlen) == NULL)
402 return got_error(GOT_ERR_BAD_PATH);
404 /* Forbid linefeeds in paths, like Git does. */
405 if (memchr(&gitcmd[cmdlen + 1], '\n', len - cmdlen) != NULL)
406 return got_error(GOT_ERR_BAD_PATH);
408 path0 = strdup(&gitcmd[cmdlen + 1]);
410 return got_error_from_errno("strdup");
412 pathlen = strlen(path);
415 * Git clients send a shell command.
416 * Trim spaces and quotes around the path.
418 while (path[0] == '\'' || path[0] == '\"' || path[0] == ' ') {
422 while (pathlen > 0 &&
423 (path[pathlen - 1] == '\'' || path[pathlen - 1] == '\"' ||
424 path[pathlen - 1] == ' ')) {
425 path[pathlen - 1] = '\0';
429 /* Deny an empty repository path. */
430 if (path[0] == '\0' || got_path_is_root_dir(path)) {
431 err = got_error(GOT_ERR_NOT_GIT_REPO);
435 if (asprintf(&abspath, "/%s", path) == -1) {
436 err = got_error_from_errno("asprintf");
439 pathlen = strlen(abspath);
440 canonpath = malloc(pathlen + 1);
441 if (canonpath == NULL) {
442 err = got_error_from_errno("malloc");
445 err = got_canonpath(abspath, canonpath, pathlen + 1);
450 while (relpath[0] == '/')
452 *repo_path = strdup(relpath);
453 if (*repo_path == NULL) {
454 err = got_error_from_errno("strdup");
457 *command = strndup(gitcmd, cmdlen);
458 if (*command == NULL)
459 err = got_error_from_errno("strndup");