diff options
Diffstat (limited to 'shell.c')
| -rw-r--r-- | shell.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/shell.c b/shell.c new file mode 100644 index 0000000000..abb862246e --- /dev/null +++ b/shell.c @@ -0,0 +1,218 @@ +#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" + +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 (prefixcmp(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 }; + /* 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 devnull_fd; + int count; + + git_extract_argv0_path(argv[0]); + + /* + * Always open file descriptors 0/1/2 to avoid clobbering files + * in die(). It also avoids not messing up when the pipes are + * dup'ed onto stdin/stdout/stderr in the child processes we spawn. + */ + devnull_fd = open("/dev/null", O_RDWR); + while (devnull_fd >= 0 && devnull_fd <= 2) + devnull_fd = dup(devnull_fd); + if (devnull_fd == -1) + die_errno("opening /dev/null failed"); + close (devnull_fd); + + /* + * 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)); + } +} |