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-rw-r--r--shell.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/shell.c b/shell.c
new file mode 100644
index 0000000000..5c0d47a5cc
--- /dev/null
+++ b/shell.c
@@ -0,0 +1,227 @@
+#include "cache.h"
+#include "quote.h"
+#include "exec_cmd.h"
+#include "strbuf.h"
+#include "run-command.h"
+
+#define COMMAND_DIR "git-shell-commands"
+#define HELP_COMMAND COMMAND_DIR "/help"
+#define NOLOGIN_COMMAND COMMAND_DIR "/no-interactive-login"
+
+static int do_generic_cmd(const char *me, char *arg)
+{
+ const char *my_argv[4];
+
+ setup_path();
+ if (!arg || !(arg = sq_dequote(arg)))
+ die("bad argument");
+ if (!starts_with(me, "git-"))
+ die("bad command");
+
+ my_argv[0] = me + 4;
+ my_argv[1] = arg;
+ my_argv[2] = NULL;
+
+ return execv_git_cmd(my_argv);
+}
+
+static int do_cvs_cmd(const char *me, char *arg)
+{
+ const char *cvsserver_argv[3] = {
+ "cvsserver", "server", NULL
+ };
+
+ if (!arg || strcmp(arg, "server"))
+ die("git-cvsserver only handles server: %s", arg);
+
+ setup_path();
+ return execv_git_cmd(cvsserver_argv);
+}
+
+static int is_valid_cmd_name(const char *cmd)
+{
+ /* Test command contains no . or / characters */
+ return cmd[strcspn(cmd, "./")] == '\0';
+}
+
+static char *make_cmd(const char *prog)
+{
+ char *prefix = xmalloc((strlen(prog) + strlen(COMMAND_DIR) + 2));
+ strcpy(prefix, COMMAND_DIR);
+ strcat(prefix, "/");
+ strcat(prefix, prog);
+ return prefix;
+}
+
+static void cd_to_homedir(void)
+{
+ const char *home = getenv("HOME");
+ if (!home)
+ die("could not determine user's home directory; HOME is unset");
+ if (chdir(home) == -1)
+ die("could not chdir to user's home directory");
+}
+
+static void run_shell(void)
+{
+ int done = 0;
+ static const char *help_argv[] = { HELP_COMMAND, NULL };
+
+ if (!access(NOLOGIN_COMMAND, F_OK)) {
+ /* Interactive login disabled. */
+ const char *argv[] = { NOLOGIN_COMMAND, NULL };
+ int status;
+
+ status = run_command_v_opt(argv, 0);
+ if (status < 0)
+ exit(127);
+ exit(status);
+ }
+
+ /* Print help if enabled */
+ run_command_v_opt(help_argv, RUN_SILENT_EXEC_FAILURE);
+
+ do {
+ struct strbuf line = STRBUF_INIT;
+ const char *prog;
+ char *full_cmd;
+ char *rawargs;
+ char *split_args;
+ const char **argv;
+ int code;
+ int count;
+
+ fprintf(stderr, "git> ");
+ if (strbuf_getline(&line, stdin, '\n') == EOF) {
+ fprintf(stderr, "\n");
+ strbuf_release(&line);
+ break;
+ }
+ strbuf_trim(&line);
+ rawargs = strbuf_detach(&line, NULL);
+ split_args = xstrdup(rawargs);
+ count = split_cmdline(split_args, &argv);
+ if (count < 0) {
+ fprintf(stderr, "invalid command format '%s': %s\n", rawargs,
+ split_cmdline_strerror(count));
+ free(split_args);
+ free(rawargs);
+ continue;
+ }
+
+ prog = argv[0];
+ if (!strcmp(prog, "")) {
+ } else if (!strcmp(prog, "quit") || !strcmp(prog, "logout") ||
+ !strcmp(prog, "exit") || !strcmp(prog, "bye")) {
+ done = 1;
+ } else if (is_valid_cmd_name(prog)) {
+ full_cmd = make_cmd(prog);
+ argv[0] = full_cmd;
+ code = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
+ if (code == -1 && errno == ENOENT) {
+ fprintf(stderr, "unrecognized command '%s'\n", prog);
+ }
+ free(full_cmd);
+ } else {
+ fprintf(stderr, "invalid command format '%s'\n", prog);
+ }
+
+ free(argv);
+ free(rawargs);
+ } while (!done);
+}
+
+static struct commands {
+ const char *name;
+ int (*exec)(const char *me, char *arg);
+} cmd_list[] = {
+ { "git-receive-pack", do_generic_cmd },
+ { "git-upload-pack", do_generic_cmd },
+ { "git-upload-archive", do_generic_cmd },
+ { "cvs", do_cvs_cmd },
+ { NULL },
+};
+
+int main(int argc, char **argv)
+{
+ char *prog;
+ const char **user_argv;
+ struct commands *cmd;
+ int count;
+
+ git_setup_gettext();
+
+ git_extract_argv0_path(argv[0]);
+
+ /*
+ * Always open file descriptors 0/1/2 to avoid clobbering files
+ * in die(). It also avoids messing up when the pipes are dup'ed
+ * onto stdin/stdout/stderr in the child processes we spawn.
+ */
+ sanitize_stdfds();
+
+ /*
+ * Special hack to pretend to be a CVS server
+ */
+ if (argc == 2 && !strcmp(argv[1], "cvs server")) {
+ argv--;
+ } else if (argc == 1) {
+ /* Allow the user to run an interactive shell */
+ cd_to_homedir();
+ if (access(COMMAND_DIR, R_OK | X_OK) == -1) {
+ die("Interactive git shell is not enabled.\n"
+ "hint: ~/" COMMAND_DIR " should exist "
+ "and have read and execute access.");
+ }
+ run_shell();
+ exit(0);
+ } else if (argc != 3 || strcmp(argv[1], "-c")) {
+ /*
+ * We do not accept any other modes except "-c" followed by
+ * "cmd arg", where "cmd" is a very limited subset of git
+ * commands or a command in the COMMAND_DIR
+ */
+ die("Run with no arguments or with -c cmd");
+ }
+
+ prog = xstrdup(argv[2]);
+ if (!strncmp(prog, "git", 3) && isspace(prog[3]))
+ /* Accept "git foo" as if the caller said "git-foo". */
+ prog[3] = '-';
+
+ for (cmd = cmd_list ; cmd->name ; cmd++) {
+ int len = strlen(cmd->name);
+ char *arg;
+ if (strncmp(cmd->name, prog, len))
+ continue;
+ arg = NULL;
+ switch (prog[len]) {
+ case '\0':
+ arg = NULL;
+ break;
+ case ' ':
+ arg = prog + len + 1;
+ break;
+ default:
+ continue;
+ }
+ exit(cmd->exec(cmd->name, arg));
+ }
+
+ cd_to_homedir();
+ count = split_cmdline(prog, &user_argv);
+ if (count >= 0) {
+ if (is_valid_cmd_name(user_argv[0])) {
+ prog = make_cmd(user_argv[0]);
+ user_argv[0] = prog;
+ execv(user_argv[0], (char *const *) user_argv);
+ }
+ free(prog);
+ free(user_argv);
+ die("unrecognized command '%s'", argv[2]);
+ } else {
+ free(prog);
+ die("invalid command format '%s': %s", argv[2],
+ split_cmdline_strerror(count));
+ }
+}