From c95ca2a228ba4ccb7085f481341c7b4a9e8cdc5e Mon Sep 17 00:00:00 2001 From: Wayne Davison Date: Mon, 24 Oct 2005 21:03:50 +0000 Subject: [PATCH] Enhanced the "pre-xfer exec" handling so that it gets the user's request info and puts that into the environment as RSYNC_REQUEST. --- clientserver.c | 107 ++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 83 insertions(+), 24 deletions(-) diff --git a/clientserver.c b/clientserver.c index e0692678..c0ace0c5 100644 --- a/clientserver.c +++ b/clientserver.c @@ -59,6 +59,8 @@ int module_id = -1; /* Length of lp_path() string when in daemon mode & not chrooted, else 0. */ unsigned int module_dirlen = 0; +#define MAX_REQ_LEN (MAXPATHLEN + 255) + /** * Run a client connected to an rsyncd. The alternative to this * function for remote-shell connections is do_cmd(). @@ -216,7 +218,27 @@ int start_inband_exchange(char *user, char *path, int f_in, int f_out, return 0; } +static char *finish_pre_exec(pid_t pid, int fd, char *request) +{ + int status = -1; + if (request) { + int len = strlen(request); + if (len > MAX_REQ_LEN) + len = MAX_REQ_LEN; + write(fd, request, len); + } + close(fd); + + if (wait_process(pid, &status, 0) < 0 + || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { + char *e; + if (asprintf(&e, "pre-xfer exec returned failure (%d)\n", status) < 0) + out_of_memory("finish_pre_exec"); + return e; + } + return NULL; +} static int rsync_module(int f_in, int f_out, int i) { @@ -226,16 +248,14 @@ static int rsync_module(int f_in, int f_out, int i) char line[BIGPATHBUFLEN]; uid_t uid = (uid_t)-2; /* canonically "nobody" */ gid_t gid = (gid_t)-2; - char *p; -#ifdef HAVE_PUTENV - char *s; -#endif + char *p, *err_msg = NULL; char *addr = client_addr(f_in); char *host = client_name(f_in); char *name = lp_name(i); int use_chroot = lp_use_chroot(i); int start_glob = 0; - int ret; + int ret, pre_exec_fd = -1; + pid_t pre_exec_pid = 0; char *request = NULL; if (!allow_access(addr, host, lp_hosts_allow(i), lp_hosts_deny(i))) { @@ -351,9 +371,7 @@ static int rsync_module(int f_in, int f_out, int i) log_init(); #ifdef HAVE_PUTENV - s = lp_prexfer_exec(i); - p = lp_postxfer_exec(i); - if ((s && *s) || (p && *p)) { + if (*lp_prexfer_exec(i) || *lp_postxfer_exec(i)) { char *modname, *modpath, *hostaddr, *hostname, *username; int status; if (asprintf(&modname, "RSYNC_MODULE_NAME=%s", name) < 0 @@ -368,15 +386,10 @@ static int rsync_module(int f_in, int f_out, int i) putenv(hostname); putenv(username); umask(orig_umask); - if (s && *s) { - status = system(s); - if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { - rprintf(FLOG, "prexfer-exec failed\n"); - io_printf(f_out, "@ERROR: prexfer-exec failed\n"); - return -1; - } - } - if (p && *p) { + /* For post-xfer exec, fork a new process to run the rsync + * daemon while this process waits for the exit status and + * runs the indicated command at that point. */ + if (*lp_postxfer_exec(i)) { pid_t pid = fork(); if (pid < 0) { rsyserr(FLOG, errno, "fork failed"); @@ -385,7 +398,8 @@ static int rsync_module(int f_in, int f_out, int i) } if (pid) { char *ret1, *ret2; - waitpid(pid, &status, 0); + if (wait_process(pid, &status, 0) < 0) + status = -1; if (asprintf(&ret1, "RSYNC_RAW_STATUS=%d", status) > 0) putenv(ret1); if (WIFEXITED(status)) @@ -394,10 +408,44 @@ static int rsync_module(int f_in, int f_out, int i) status = -1; if (asprintf(&ret2, "RSYNC_EXIT_STATUS=%d", status) > 0) putenv(ret2); - system(p); + system(lp_postxfer_exec(i)); _exit(status); } } + /* For pre-xfer exec, fork a child process to run the indicated + * command, though it first waits for the parent process to + * send us the user's request via a pipe. */ + if (*lp_prexfer_exec(i)) { + int fds[2]; + if (pipe(fds) < 0 || (pre_exec_pid = fork()) < 0) { + rsyserr(FLOG, errno, "pre-xfer exec preparation failed"); + io_printf(f_out, "@ERROR: pre-xfer exec preparation failed\n"); + return -1; + } + if (pre_exec_pid == 0) { + char buf[MAX_REQ_LEN+1]; + int len; + close(fds[1]); + set_blocking(fds[0]); + len = read(fds[0], buf, MAX_REQ_LEN); + close(fds[0]); + if (len <= 0) + _exit(1); + buf[len] = '\0'; + if (asprintf(&p, "RSYNC_REQUEST=%s", buf) < 0) + out_of_memory("rsync_module"); + putenv(p); + close(STDIN_FILENO); + close(STDOUT_FILENO); + status = system(lp_prexfer_exec(i)); + if (!WIFEXITED(status)) + _exit(1); + _exit(WEXITSTATUS(status)); + } + close(fds[0]); + set_blocking(fds[1]); + pre_exec_fd = fds[1]; + } umask(0); } #endif @@ -515,15 +563,24 @@ static int rsync_module(int f_in, int f_out, int i) start_glob = 1; break; case 1: + if (pre_exec_pid) { + err_msg = finish_pre_exec(pre_exec_pid, + pre_exec_fd, p); + pre_exec_pid = 0; + } request = strdup(p); start_glob = 2; /* FALL THROUGH */ default: - glob_expand(name, &argv, &argc, &maxargs); + if (!err_msg) + glob_expand(name, &argv, &argc, &maxargs); break; } } + if (pre_exec_pid) + err_msg = finish_pre_exec(pre_exec_pid, pre_exec_fd, request); + verbose = 0; /* future verbosity is controlled by client options */ ret = parse_arguments(&argc, (const char ***) &argv, 0); @@ -552,7 +609,7 @@ static int rsync_module(int f_in, int f_out, int i) if (protocol_version < 23 && (protocol_version == 22 || am_sender)) io_start_multiplex_out(); - else if (!ret) { + else if (!ret || err_msg) { /* We have to get I/O multiplexing started so that we can * get the error back to the client. This means getting * the protocol setup finished first in later versions. */ @@ -578,8 +635,11 @@ static int rsync_module(int f_in, int f_out, int i) io_start_multiplex_out(); } - if (!ret) { - option_error(); + if (!ret || err_msg) { + if (err_msg) + rprintf(FERROR, err_msg); + else + option_error(); msleep(400); exit_cleanup(RERR_UNSUPPORTED); } @@ -684,7 +744,6 @@ int start_daemon(int f_in, int f_out) return rsync_module(f_in, f_out, i); } - int daemon_main(void) { char *pid_file; -- 2.34.1