diff options
| -rw-r--r-- | networking/ftpd.c | 79 |
1 files changed, 57 insertions, 22 deletions
diff --git a/networking/ftpd.c b/networking/ftpd.c index b295ddf4f..0a4b185a1 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -87,7 +87,9 @@ enum { struct globals { int pasv_listen_fd; - int proc_self_fd; +#if !BB_MMU + int root_fd; +#endif int local_file_fd; unsigned end_time; unsigned timeout; @@ -615,7 +617,13 @@ static int popen_ls(const char *opt) { char *cwd; - const char *argv[5] = { "ftpd", opt, NULL, G.ftp_arg, NULL }; + const char *argv[] = { + "ftpd", + opt, + BB_MMU ? "--" : NULL, + G.ftp_arg, + NULL + }; struct fd_pair outfd; pid_t pid; @@ -623,25 +631,40 @@ popen_ls(const char *opt) xpiped_pair(outfd); /*fflush(NULL); - so far we dont use stdio on output */ - pid = vfork(); - switch (pid) { - case -1: /* failure */ - bb_perror_msg_and_die("vfork"); - case 0: /* child */ - /* NB: close _first_, then move fds! */ + pid = BB_MMU ? fork() : vfork(); + if (pid < 0) + bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork"); + + if (pid == 0) { + /* child */ +#if !BB_MMU + if (fchdir(G.root_fd) != 0) + _exit(127); + close(G.root_fd); +#endif + /* NB: close _first_, then move fd! */ close(outfd.rd); xmove_fd(outfd.wr, STDOUT_FILENO); + /* Opening /dev/null in chroot is hard. + * Just making sure STDIN_FILENO is opened + * to something harmless. Paranoia, + * ls won't read it anyway */ close(STDIN_FILENO); - /* xopen("/dev/null", O_RDONLY); - chroot may lack it! */ - if (fchdir(G.proc_self_fd) == 0) { - close(G.proc_self_fd); - argv[2] = cwd; - /* ftpd ls helper chdirs to argv[2], - * preventing peer from seeing /proc/self - */ - execv("exe", (char**) argv); - } + dup(STDOUT_FILENO); /* copy will become STDIN_FILENO */ +#if !BB_MMU + /* ftpd ls helper chdirs to argv[2], + * preventing peer from seeing real root we are in now + */ + argv[2] = cwd; + /* + 1: we must use relative path here if in chroot. + * For example, execv("/proc/self/exe") will fail, since + * it looks for "/proc/self/exe" _relative to chroot!_ */ + execv(CONFIG_BUSYBOX_EXEC_PATH + 1, (char**) argv); _exit(127); +#else + memset(&G, 0, sizeof(G)); + exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv)); +#endif } /* parent */ @@ -1006,15 +1029,21 @@ enum { const_TYPE = mk_const4('T', 'Y', 'P', 'E'), const_USER = mk_const4('U', 'S', 'E', 'R'), +#if !BB_MMU OPT_l = (1 << 0), OPT_1 = (1 << 1), - OPT_v = (1 << 2), - OPT_S = (1 << 3), - OPT_w = (1 << 4), +#endif + OPT_v = (1 << ((!BB_MMU) * 2 + 0)), + OPT_S = (1 << ((!BB_MMU) * 2 + 1)), + OPT_w = (1 << ((!BB_MMU) * 2 + 2)) * ENABLE_FEATURE_FTP_WRITE, }; int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +#if !BB_MMU int ftpd_main(int argc, char **argv) +#else +int ftpd_main(int argc UNUSED_PARAM, char **argv) +#endif { unsigned abs_timeout; smallint opts; @@ -1024,16 +1053,20 @@ int ftpd_main(int argc, char **argv) abs_timeout = 1 * 60 * 60; G.timeout = 2 * 60; opt_complementary = "t+:T+:vv"; +#if BB_MMU + opts = getopt32(argv, "vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose); +#else opts = getopt32(argv, "l1vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose); if (opts & (OPT_l|OPT_1)) { /* Our secret backdoor to ls */ - memset(&G, 0, sizeof(G)); /* TODO: pass -n too? */ /* --group-directories-first would be nice, but ls don't do that yet */ xchdir(argv[2]); argv[2] = (char*)"--"; + memset(&G, 0, sizeof(G)); return ls_main(argc, argv); } +#endif if (abs_timeout | G.timeout) { if (abs_timeout == 0) abs_timeout = INT_MAX; @@ -1065,7 +1098,9 @@ int ftpd_main(int argc, char **argv) if (logmode) applet_name = xasprintf("%s[%u]", applet_name, (int)getpid()); - G.proc_self_fd = xopen("/proc/self", O_RDONLY | O_DIRECTORY); +#if !BB_MMU + G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); +#endif if (argv[optind]) { xchdir(argv[optind]); |