freshlybakedca.ke
Git fork
1#include "git-compat-util.h"
2#include "quote.h"
3#include "exec-cmd.h"
4#include "strbuf.h"
5#include "run-command.h"
6#include "alias.h"
7
8#define COMMAND_DIR "git-shell-commands"
9#define HELP_COMMAND COMMAND_DIR "/help"
10#define NOLOGIN_COMMAND COMMAND_DIR "/no-interactive-login"
11
12static int do_generic_cmd(const char *me, char *arg)
13{
14 const char *my_argv[4];
15
16 setup_path();
17 if (!arg || !(arg = sq_dequote(arg)) || *arg == '-')
18 die("bad argument");
19 if (!skip_prefix(me, "git-", &me))
20 die("bad command");
21
22 my_argv[0] = me;
23 my_argv[1] = arg;
24 my_argv[2] = NULL;
25
26 return execv_git_cmd(my_argv);
27}
28
29static int is_valid_cmd_name(const char *cmd)
30{
31 /* Test command contains no . or / characters */
32 return cmd[strcspn(cmd, "./")] == '\0';
33}
34
35static char *make_cmd(const char *prog)
36{
37 return xstrfmt("%s/%s", COMMAND_DIR, prog);
38}
39
40static void cd_to_homedir(void)
41{
42 const char *home = getenv("HOME");
43 if (!home)
44 die("could not determine user's home directory; HOME is unset");
45 if (chdir(home) == -1)
46 die("could not chdir to user's home directory");
47}
48
49#define MAX_INTERACTIVE_COMMAND (4*1024*1024)
50
51static void run_shell(void)
52{
53 int done = 0;
54 struct child_process help_cmd = CHILD_PROCESS_INIT;
55
56 if (!access(NOLOGIN_COMMAND, F_OK)) {
57 /* Interactive login disabled. */
58 struct child_process nologin_cmd = CHILD_PROCESS_INIT;
59 int status;
60
61 strvec_push(&nologin_cmd.args, NOLOGIN_COMMAND);
62 status = run_command(&nologin_cmd);
63 if (status < 0)
64 exit(127);
65 exit(status);
66 }
67
68 /* Print help if enabled */
69 help_cmd.silent_exec_failure = 1;
70 strvec_push(&help_cmd.args, HELP_COMMAND);
71 run_command(&help_cmd);
72
73 do {
74 const char *prog;
75 char *full_cmd;
76 char *rawargs;
77 size_t len;
78 char *split_args;
79 const char **argv;
80 int code;
81 int count;
82
83 fprintf(stderr, "git> ");
84
85 /*
86 * Avoid using a strbuf or git_read_line_interactively() here.
87 * We don't want to allocate arbitrary amounts of memory on
88 * behalf of a possibly untrusted client, and we're subject to
89 * OS limits on command length anyway.
90 */
91 fflush(stdout);
92 rawargs = xmalloc(MAX_INTERACTIVE_COMMAND);
93 if (!fgets(rawargs, MAX_INTERACTIVE_COMMAND, stdin)) {
94 fprintf(stderr, "\n");
95 free(rawargs);
96 break;
97 }
98 len = strlen(rawargs);
99
100 /*
101 * If we truncated due to our input buffer size, reject the
102 * command. That's better than running bogus input, and
103 * there's a good chance it's just malicious garbage anyway.
104 */
105 if (len >= MAX_INTERACTIVE_COMMAND - 1)
106 die("invalid command format: input too long");
107
108 if (len > 0 && rawargs[len - 1] == '\n') {
109 if (--len > 0 && rawargs[len - 1] == '\r')
110 --len;
111 rawargs[len] = '\0';
112 }
113
114 split_args = xstrdup(rawargs);
115 count = split_cmdline(split_args, &argv);
116 if (count < 0) {
117 fprintf(stderr, "invalid command format '%s': %s\n", rawargs,
118 split_cmdline_strerror(count));
119 free(split_args);
120 free(rawargs);
121 continue;
122 }
123
124 prog = argv[0];
125 if (!strcmp(prog, "")) {
126 } else if (!strcmp(prog, "quit") || !strcmp(prog, "logout") ||
127 !strcmp(prog, "exit") || !strcmp(prog, "bye")) {
128 done = 1;
129 } else if (is_valid_cmd_name(prog)) {
130 struct child_process cmd = CHILD_PROCESS_INIT;
131
132 full_cmd = make_cmd(prog);
133 argv[0] = full_cmd;
134 cmd.silent_exec_failure = 1;
135 strvec_pushv(&cmd.args, argv);
136 code = run_command(&cmd);
137 if (code == -1 && errno == ENOENT) {
138 fprintf(stderr, "unrecognized command '%s'\n", prog);
139 }
140 free(full_cmd);
141 } else {
142 fprintf(stderr, "invalid command format '%s'\n", prog);
143 }
144
145 free(argv);
146 free(split_args);
147 free(rawargs);
148 } while (!done);
149}
150
151static struct commands {
152 const char *name;
153 int (*exec)(const char *me, char *arg);
154} cmd_list[] = {
155 { "git-receive-pack", do_generic_cmd },
156 { "git-upload-pack", do_generic_cmd },
157 { "git-upload-archive", do_generic_cmd },
158 { NULL },
159};
160
161int cmd_main(int argc, const char **argv)
162{
163 char *prog;
164 const char **user_argv;
165 struct commands *cmd;
166 int count;
167
168 /*
169 * Special hack to pretend to be a CVS server
170 */
171 if (argc == 2 && !strcmp(argv[1], "cvs server")) {
172 argv--;
173 } else if (argc == 1) {
174 /* Allow the user to run an interactive shell */
175 cd_to_homedir();
176 if (access(COMMAND_DIR, R_OK | X_OK) == -1) {
177 die("Interactive git shell is not enabled.\n"
178 "hint: ~/" COMMAND_DIR " should exist "
179 "and have read and execute access.");
180 }
181 run_shell();
182 exit(0);
183 } else if (argc != 3 || strcmp(argv[1], "-c")) {
184 /*
185 * We do not accept any other modes except "-c" followed by
186 * "cmd arg", where "cmd" is a very limited subset of git
187 * commands or a command in the COMMAND_DIR
188 */
189 die("Run with no arguments or with -c cmd");
190 }
191
192 prog = xstrdup(argv[2]);
193 if (!strncmp(prog, "git", 3) && isspace(prog[3]))
194 /* Accept "git foo" as if the caller said "git-foo". */
195 prog[3] = '-';
196
197 for (cmd = cmd_list ; cmd->name ; cmd++) {
198 int len = strlen(cmd->name);
199 char *arg;
200 if (strncmp(cmd->name, prog, len))
201 continue;
202 arg = NULL;
203 switch (prog[len]) {
204 case '\0':
205 arg = NULL;
206 break;
207 case ' ':
208 arg = prog + len + 1;
209 break;
210 default:
211 continue;
212 }
213 return cmd->exec(cmd->name, arg);
214 }
215
216 cd_to_homedir();
217 count = split_cmdline(prog, &user_argv);
218 if (count >= 0) {
219 if (is_valid_cmd_name(user_argv[0])) {
220 char *cmd = make_cmd(user_argv[0]);
221 execv(cmd, (char *const *) user_argv);
222 }
223 free(prog);
224 free(user_argv);
225 die("unrecognized command '%s'", argv[2]);
226 } else {
227 free(prog);
228 die("invalid command format '%s': %s", argv[2],
229 split_cmdline_strerror(count));
230 }
231}