1 5dcb3a43 2023-04-01 thomas /*
  2 5dcb3a43 2023-04-01 thomas  * Copyright (c) 2023 Stefan Sperling <stsp@openbsd.org>
  3 5dcb3a43 2023-04-01 thomas  *
  4 5dcb3a43 2023-04-01 thomas  * Permission to use, copy, modify, and distribute this software for any
  5 5dcb3a43 2023-04-01 thomas  * purpose with or without fee is hereby granted, provided that the above
  6 5dcb3a43 2023-04-01 thomas  * copyright notice and this permission notice appear in all copies.
  7 5dcb3a43 2023-04-01 thomas  *
  8 5dcb3a43 2023-04-01 thomas  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 5dcb3a43 2023-04-01 thomas  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 5dcb3a43 2023-04-01 thomas  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 5dcb3a43 2023-04-01 thomas  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 5dcb3a43 2023-04-01 thomas  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 5dcb3a43 2023-04-01 thomas  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 5dcb3a43 2023-04-01 thomas  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 5dcb3a43 2023-04-01 thomas  */
 16 5dcb3a43 2023-04-01 thomas 
 17 5dcb3a43 2023-04-01 thomas /*
 18 5dcb3a43 2023-04-01 thomas  * Resolve path namespace conflicts for git-upload-pack and git-receive-pack.
 19 5dcb3a43 2023-04-01 thomas  */
 20 5dcb3a43 2023-04-01 thomas 
 21 5dcb3a43 2023-04-01 thomas #include <sys/queue.h>
 22 5dcb3a43 2023-04-01 thomas #include <sys/types.h>
 23 5dcb3a43 2023-04-01 thomas #include <sys/uio.h>
 24 5dcb3a43 2023-04-01 thomas 
 25 5dcb3a43 2023-04-01 thomas #include <err.h>
 26 5dcb3a43 2023-04-01 thomas #include <errno.h>
 27 5dcb3a43 2023-04-01 thomas #include <event.h>
 28 5dcb3a43 2023-04-01 thomas #include <imsg.h>
 29 5dcb3a43 2023-04-01 thomas #include <limits.h>
 30 5dcb3a43 2023-04-01 thomas #include <stdio.h>
 31 5dcb3a43 2023-04-01 thomas #include <stdlib.h>
 32 5dcb3a43 2023-04-01 thomas #include <string.h>
 33 5dcb3a43 2023-04-01 thomas #include <sha1.h>
 34 5dcb3a43 2023-04-01 thomas #include <sha2.h>
 35 5dcb3a43 2023-04-01 thomas #include <syslog.h>
 36 5dcb3a43 2023-04-01 thomas #include <util.h>
 37 5dcb3a43 2023-04-01 thomas #include <unistd.h>
 38 5dcb3a43 2023-04-01 thomas 
 39 5dcb3a43 2023-04-01 thomas #include "got_error.h"
 40 5dcb3a43 2023-04-01 thomas #include "got_path.h"
 41 5dcb3a43 2023-04-01 thomas #include "got_serve.h"
 42 5dcb3a43 2023-04-01 thomas 
 43 5dcb3a43 2023-04-01 thomas #include "gotd.h"
 44 5dcb3a43 2023-04-01 thomas #include "log.h"
 45 5dcb3a43 2023-04-01 thomas 
 46 5dcb3a43 2023-04-01 thomas #ifndef GITWRAPPER_GIT_LIBEXEC_DIR
 47 5dcb3a43 2023-04-01 thomas #define GITWRAPPER_GIT_LIBEXEC_DIR "/usr/local/libexec/git"
 48 5dcb3a43 2023-04-01 thomas #endif
 49 5dcb3a43 2023-04-01 thomas 
 50 5dcb3a43 2023-04-01 thomas #ifndef GITWRAPPER_MY_SERVER_PROG
 51 5dcb3a43 2023-04-01 thomas #define GITWRAPPER_MY_SERVER_PROG "gotsh"
 52 5dcb3a43 2023-04-01 thomas #endif
 53 5dcb3a43 2023-04-01 thomas 
 54 5dcb3a43 2023-04-01 thomas 
 55 5dcb3a43 2023-04-01 thomas __dead static void
 56 5dcb3a43 2023-04-01 thomas usage(void)
 57 5dcb3a43 2023-04-01 thomas {
 58 5dcb3a43 2023-04-01 thomas 	fprintf(stderr, "usage: %s -c '%s|%s repository-path'\n",
 59 5dcb3a43 2023-04-01 thomas 	    getprogname(), GOT_SERVE_CMD_SEND, GOT_SERVE_CMD_FETCH);
 60 5dcb3a43 2023-04-01 thomas 	exit(1);
 61 5dcb3a43 2023-04-01 thomas }
 62 5dcb3a43 2023-04-01 thomas 
 63 5dcb3a43 2023-04-01 thomas /*
 64 5dcb3a43 2023-04-01 thomas  * Unveil the specific programs we want to start and hide everything else.
 65 5dcb3a43 2023-04-01 thomas  * This is important to limit the impact of our "exec" pledge.
 66 5dcb3a43 2023-04-01 thomas  */
 67 5dcb3a43 2023-04-01 thomas static const struct got_error *
 68 5dcb3a43 2023-04-01 thomas apply_unveil(const char *myserver)
 69 5dcb3a43 2023-04-01 thomas {
 70 5dcb3a43 2023-04-01 thomas 	const char *fetchcmd = GITWRAPPER_GIT_LIBEXEC_DIR "/" \
 71 5dcb3a43 2023-04-01 thomas 		GOT_SERVE_CMD_FETCH;
 72 5dcb3a43 2023-04-01 thomas 	const char *sendcmd = GITWRAPPER_GIT_LIBEXEC_DIR "/" \
 73 5dcb3a43 2023-04-01 thomas 		GOT_SERVE_CMD_SEND;
 74 5dcb3a43 2023-04-01 thomas 
 75 5dcb3a43 2023-04-01 thomas #ifdef PROFILE
 76 5dcb3a43 2023-04-01 thomas 	if (unveil("gmon.out", "rwc") != 0)
 77 5dcb3a43 2023-04-01 thomas 		return got_error_from_errno2("unveil", "gmon.out");
 78 5dcb3a43 2023-04-01 thomas #endif
 79 5dcb3a43 2023-04-01 thomas 	if (unveil(fetchcmd, "x") != 0)
 80 5dcb3a43 2023-04-01 thomas 		return got_error_from_errno2("unveil", fetchcmd);
 81 5dcb3a43 2023-04-01 thomas 
 82 5dcb3a43 2023-04-01 thomas 	if (unveil(sendcmd, "x") != 0)
 83 5dcb3a43 2023-04-01 thomas 		return got_error_from_errno2("unveil", sendcmd);
 84 5dcb3a43 2023-04-01 thomas 
 85 5dcb3a43 2023-04-01 thomas 	if (myserver && unveil(myserver, "x") != 0)
 86 5dcb3a43 2023-04-01 thomas 		return got_error_from_errno2("unveil", myserver);
 87 5dcb3a43 2023-04-01 thomas 
 88 5dcb3a43 2023-04-01 thomas 	if (unveil(NULL, NULL) != 0)
 89 5dcb3a43 2023-04-01 thomas 		return got_error_from_errno("unveil");
 90 5dcb3a43 2023-04-01 thomas 
 91 5dcb3a43 2023-04-01 thomas 	return NULL;
 92 5dcb3a43 2023-04-01 thomas }
 93 5dcb3a43 2023-04-01 thomas 
 94 5dcb3a43 2023-04-01 thomas int
 95 5dcb3a43 2023-04-01 thomas main(int argc, char *argv[])
 96 5dcb3a43 2023-04-01 thomas {
 97 5dcb3a43 2023-04-01 thomas 	const struct got_error *error;
 98 5dcb3a43 2023-04-01 thomas 	const char *confpath = NULL;
 99 5dcb3a43 2023-04-01 thomas 	char *command = NULL, *repo_name = NULL; /* for matching gotd.conf */
100 5dcb3a43 2023-04-01 thomas 	char *myserver = NULL;
101 5dcb3a43 2023-04-01 thomas 	const char *repo_path = NULL; /* as passed on the command line */
102 5dcb3a43 2023-04-01 thomas 	const char *relpath;
103 5dcb3a43 2023-04-01 thomas 	char *gitcommand = NULL;
104 5dcb3a43 2023-04-01 thomas 	struct gotd gotd;
105 5dcb3a43 2023-04-01 thomas 	struct gotd_repo *repo = NULL;
106 5dcb3a43 2023-04-01 thomas 
107 5dcb3a43 2023-04-01 thomas 	log_init(1, LOG_USER); /* Log to stderr. */
108 5dcb3a43 2023-04-01 thomas 
109 5dcb3a43 2023-04-01 thomas #ifndef PROFILE
110 44e35bfc 2023-04-01 thomas 	if (pledge("stdio rpath exec unveil", NULL) == -1)
111 5dcb3a43 2023-04-01 thomas 		err(1, "pledge");
112 5dcb3a43 2023-04-01 thomas #endif
113 5dcb3a43 2023-04-01 thomas 
114 5dcb3a43 2023-04-01 thomas 	/*
115 5dcb3a43 2023-04-01 thomas 	 * Look up our own server program in PATH so we can unveil(2) it.
116 5dcb3a43 2023-04-01 thomas 	 * This call only errors out upon memory allocation failure.
117 5dcb3a43 2023-04-01 thomas 	 * If the program cannot be found then myserver will be set to NULL.
118 5dcb3a43 2023-04-01 thomas 	 */
119 5dcb3a43 2023-04-01 thomas 	error = got_path_find_prog(&myserver, GITWRAPPER_MY_SERVER_PROG);
120 5dcb3a43 2023-04-01 thomas 	if (error)
121 5dcb3a43 2023-04-01 thomas 		goto done;
122 5dcb3a43 2023-04-01 thomas 
123 5dcb3a43 2023-04-01 thomas 	/*
124 5dcb3a43 2023-04-01 thomas 	 * Run parse_config() before unveil(2) because parse_config()
125 5dcb3a43 2023-04-01 thomas 	 * checks whether repository paths exist on disk.
126 5dcb3a43 2023-04-01 thomas 	 * Parsing errors and warnings will be logged to stderr.
127 5dcb3a43 2023-04-01 thomas 	 * Upon failure we will run Git's native tooling so do not
128 5dcb3a43 2023-04-01 thomas 	 * bother checking for errors here.
129 5dcb3a43 2023-04-01 thomas 	 */
130 5dcb3a43 2023-04-01 thomas 	confpath = getenv("GOTD_CONF_PATH");
131 5dcb3a43 2023-04-01 thomas 	if (confpath == NULL)
132 5dcb3a43 2023-04-01 thomas 		confpath = GOTD_CONF_PATH;
133 7554713a 2023-04-01 thomas 	parse_config(confpath, PROC_GOTD, &gotd, 0);
134 5dcb3a43 2023-04-01 thomas 
135 5dcb3a43 2023-04-01 thomas 	error = apply_unveil(myserver);
136 5dcb3a43 2023-04-01 thomas 	if (error)
137 5dcb3a43 2023-04-01 thomas 		goto done;
138 5dcb3a43 2023-04-01 thomas 
139 5dcb3a43 2023-04-01 thomas #ifndef PROFILE
140 44e35bfc 2023-04-01 thomas 	if (pledge("stdio exec", NULL) == -1)
141 5dcb3a43 2023-04-01 thomas 		err(1, "pledge");
142 5dcb3a43 2023-04-01 thomas #endif
143 5dcb3a43 2023-04-01 thomas 
144 5dcb3a43 2023-04-01 thomas 	if (strcmp(getprogname(), GOT_SERVE_CMD_SEND) == 0 ||
145 5dcb3a43 2023-04-01 thomas 	    strcmp(getprogname(), GOT_SERVE_CMD_FETCH) == 0) {
146 5dcb3a43 2023-04-01 thomas 		if (argc != 2)
147 5dcb3a43 2023-04-01 thomas 			usage();
148 5dcb3a43 2023-04-01 thomas 		command = strdup(getprogname());
149 5dcb3a43 2023-04-01 thomas 		if (command == NULL) {
150 5dcb3a43 2023-04-01 thomas 			error = got_error_from_errno("strdup");
151 5dcb3a43 2023-04-01 thomas 			goto done;
152 5dcb3a43 2023-04-01 thomas 		}
153 5dcb3a43 2023-04-01 thomas 		repo_path = argv[1];
154 5dcb3a43 2023-04-01 thomas 		relpath = argv[1];
155 5dcb3a43 2023-04-01 thomas 		while (relpath[0] == '/')
156 5dcb3a43 2023-04-01 thomas 			relpath++;
157 5dcb3a43 2023-04-01 thomas 		repo_name = strdup(relpath);
158 5dcb3a43 2023-04-01 thomas 		if (repo_name == NULL) {
159 5dcb3a43 2023-04-01 thomas 			error = got_error_from_errno("strdup");
160 5dcb3a43 2023-04-01 thomas 			goto done;
161 5dcb3a43 2023-04-01 thomas 		}
162 5dcb3a43 2023-04-01 thomas 	} else {
163 5dcb3a43 2023-04-01 thomas 		if (argc != 3 || strcmp(argv[1], "-c") != 0)
164 5dcb3a43 2023-04-01 thomas 			usage();
165 5dcb3a43 2023-04-01 thomas 		repo_path = argv[2];
166 5dcb3a43 2023-04-01 thomas 		error = got_serve_parse_command(&command, &repo_name,
167 5dcb3a43 2023-04-01 thomas 		    repo_path);
168 5dcb3a43 2023-04-01 thomas 		if (error && error->code == GOT_ERR_BAD_PACKET)
169 5dcb3a43 2023-04-01 thomas 			usage();
170 5dcb3a43 2023-04-01 thomas 		if (error)
171 5dcb3a43 2023-04-01 thomas 			goto done;
172 5dcb3a43 2023-04-01 thomas 	}
173 5dcb3a43 2023-04-01 thomas 
174 5dcb3a43 2023-04-01 thomas 	repo = gotd_find_repo_by_name(repo_name, &gotd);
175 5dcb3a43 2023-04-01 thomas 
176 5dcb3a43 2023-04-01 thomas 	/*
177 9c9f0ee1 2023-04-01 thomas 	 * Invoke our custom Git server if the repository was found
178 9c9f0ee1 2023-04-01 thomas 	 * in gotd.conf. Otherwise invoke native git(1) tooling.
179 5dcb3a43 2023-04-01 thomas 	 */
180 44e35bfc 2023-04-01 thomas 	if (repo) {
181 44e35bfc 2023-04-01 thomas 		if (myserver == NULL) {
182 44e35bfc 2023-04-01 thomas 			error = got_error_fmt(GOT_ERR_NO_PROG,
183 44e35bfc 2023-04-01 thomas 			    "cannot run '%s'",
184 44e35bfc 2023-04-01 thomas 			    GITWRAPPER_MY_SERVER_PROG);
185 44e35bfc 2023-04-01 thomas 			goto done;
186 5dcb3a43 2023-04-01 thomas 		}
187 44e35bfc 2023-04-01 thomas 		execl(myserver, command, repo_name, (char *)NULL);
188 44e35bfc 2023-04-01 thomas 		error = got_error_from_errno2("execl", myserver);
189 44e35bfc 2023-04-01 thomas 	} else {
190 44e35bfc 2023-04-01 thomas 		if (asprintf(&gitcommand, "%s/%s",
191 44e35bfc 2023-04-01 thomas 		    GITWRAPPER_GIT_LIBEXEC_DIR, command) == -1) {
192 44e35bfc 2023-04-01 thomas 			error = got_error_from_errno("asprintf");
193 44e35bfc 2023-04-01 thomas 			goto done;
194 44e35bfc 2023-04-01 thomas 		}
195 44e35bfc 2023-04-01 thomas 		execl(gitcommand, gitcommand, repo_path, (char *)NULL);
196 44e35bfc 2023-04-01 thomas 		error = got_error_from_errno2("execl", gitcommand);
197 5dcb3a43 2023-04-01 thomas 	}
198 5dcb3a43 2023-04-01 thomas 
199 5dcb3a43 2023-04-01 thomas done:
200 5dcb3a43 2023-04-01 thomas 	free(command);
201 5dcb3a43 2023-04-01 thomas 	free(repo_name);
202 5dcb3a43 2023-04-01 thomas 	free(myserver);
203 5dcb3a43 2023-04-01 thomas 	free(gitcommand);
204 5dcb3a43 2023-04-01 thomas 	if (error) {
205 5dcb3a43 2023-04-01 thomas 		fprintf(stderr, "%s: %s\n", getprogname(), error->msg);
206 5dcb3a43 2023-04-01 thomas 		return 1;
207 5dcb3a43 2023-04-01 thomas 	}
208 5dcb3a43 2023-04-01 thomas 
209 5dcb3a43 2023-04-01 thomas 	return 0;
210 5dcb3a43 2023-04-01 thomas }