From c41cba5a578b278dc7d57ef97234a2a67e076d20 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Mon, 9 Mar 2009 15:46:07 +0000 Subject: [PATCH] ftpd: reuse ls applet for LIST/NLST/STAT generation function old new delta popen_ls - 211 +211 ftpd_main 1760 1826 +66 handle_dir_common 199 228 +29 get_remote_transfer_fd 89 104 +15 replace_char 30 34 +4 handle_upload_common 263 265 +2 bind_for_passive_mode 129 121 -8 cmdio_write 84 62 -22 escape_text 166 136 -30 init_data_sock_params 81 - -81 ftpdataio_dispose_transfer_fd 87 - -87 write_dirstats 149 - -149 write_filestats 603 - -603 ------------------------------------------------------------------------------ (add/remove: 1/4 grow/shrink: 11/5 up/down: 384/-986) Total: -602 bytes text data bss dec hex filename 808804 476 7864 817144 c77f8 busybox_old 808156 476 7864 816496 c7570 busybox_unstripped --- coreutils/Kbuild | 1 + coreutils/ls.c | 1 - include/libbb.h | 2 + networking/ftpd.c | 400 ++++++++++++++++++---------------------------- 4 files changed, 157 insertions(+), 247 deletions(-) diff --git a/coreutils/Kbuild b/coreutils/Kbuild index 67c56588a..57100a9cf 100644 --- a/coreutils/Kbuild +++ b/coreutils/Kbuild @@ -44,6 +44,7 @@ lib-$(CONFIG_LENGTH) += length.o lib-$(CONFIG_LN) += ln.o lib-$(CONFIG_LOGNAME) += logname.o lib-$(CONFIG_LS) += ls.o +lib-$(CONFIG_FTPD) += ls.o lib-$(CONFIG_MD5SUM) += md5_sha1_sum.o lib-$(CONFIG_MKDIR) += mkdir.o lib-$(CONFIG_MKFIFO) += mkfifo.o diff --git a/coreutils/ls.c b/coreutils/ls.c index 7b65d049e..f4f2724c5 100644 --- a/coreutils/ls.c +++ b/coreutils/ls.c @@ -864,7 +864,6 @@ static const char ls_color_opt[] ALIGN1 = #endif -int ls_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int ls_main(int argc UNUSED_PARAM, char **argv) { struct dnode **dnd; diff --git a/include/libbb.h b/include/libbb.h index 7d6ea9029..80a1c912c 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -917,6 +917,8 @@ int test_main(int argc, char **argv) USE_TEST(MAIN_EXTERNALLY_VISIBLE); int kill_main(int argc, char **argv) USE_KILL(MAIN_EXTERNALLY_VISIBLE); /* Similar, but used by chgrp, not shell */ int chown_main(int argc, char **argv) USE_CHOWN(MAIN_EXTERNALLY_VISIBLE); +/* Used by ftpd */ +int ls_main(int argc, char **argv) USE_LS(MAIN_EXTERNALLY_VISIBLE); /* Don't need USE_xxx() guard for these */ int gunzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int bunzip2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; diff --git a/networking/ftpd.c b/networking/ftpd.c index e83066032..2a7d8006b 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -63,9 +63,24 @@ #define STR1(s) #s #define STR(s) STR1(s) +/* Convert a constant to 3-digit string, packed into uint32_t */ enum { - OPT_v = (1 << 0), - OPT_w = (1 << 1), + /* Shift for Nth decimal digit */ + SHIFT0 = 16 * BB_LITTLE_ENDIAN + 8 * BB_BIG_ENDIAN, + SHIFT1 = 8 * BB_LITTLE_ENDIAN + 16 * BB_BIG_ENDIAN, + SHIFT2 = 0 * BB_LITTLE_ENDIAN + 24 * BB_BIG_ENDIAN, +}; +#define STRNUM32(s) (uint32_t)(0 \ + | (('0' + ((s) / 1 % 10)) << SHIFT0) \ + | (('0' + ((s) / 10 % 10)) << SHIFT1) \ + | (('0' + ((s) / 100 % 10)) << SHIFT2) \ +) + +enum { + OPT_l = (1 << 0), + OPT_1 = (1 << 1), + OPT_v = (1 << 2), + OPT_w = (1 << 3), #define mk_const4(a,b,c,d) (((a * 0x100 + b) * 0x100 + c) * 0x100 + d) #define mk_const3(a,b,c) ((a * 0x100 + b) * 0x100 + c) @@ -106,78 +121,84 @@ struct globals { len_and_sockaddr *local_addr; len_and_sockaddr *port_addr; int pasv_listen_fd; - int data_fd; + int proc_self_fd; off_t restart_pos; char *ftp_cmd; char *ftp_arg; #if ENABLE_FEATURE_FTP_WRITE char *rnfr_filename; #endif - smallint opts; }; #define G (*(struct globals*)&bb_common_bufsiz1) #define INIT_G() do { } while (0) static char * -escape_text(const char *prepend, const char *str, char from, const char *to, char append) +escape_text(const char *prepend, const char *str, unsigned escapee) { - size_t retlen, remainlen, chunklen, tolen; - const char *remain; + unsigned retlen, remainlen, chunklen; char *ret, *found; + char append; - remain = str; - remainlen = strlen(str); - tolen = strlen(to); + append = (char)escapee; + escapee >>= 8; - /* Simply alloc strlen(str)*strlen(to). "to" is max 2 so it's ok */ + remainlen = strlen(str); retlen = strlen(prepend); - ret = xmalloc(retlen + remainlen * tolen + 1 + 1); + ret = xmalloc(retlen + remainlen * 2 + 1 + 1); strcpy(ret, prepend); for (;;) { - found = strchrnul(remain, from); - chunklen = found - remain; + found = strchrnul(str, escapee); + chunklen = found - str + 1; - /* Copy chunk which doesn't contain 'from' to ret */ - memcpy(&ret[retlen], remain, chunklen); + /* Copy chunk up to and including escapee (or NUL) to ret */ + memcpy(ret + retlen, str, chunklen); retlen += chunklen; - if (*found != '\0') { - /* Now copy 'to' instead of 'from' */ - memcpy(&ret[retlen], to, tolen); - retlen += tolen; - - remain = found + 1; - } else { - ret[retlen] = append; - ret[retlen+1] = '\0'; + if (*found == '\0') { + /* It wasn't escapee, it was NUL! */ + ret[retlen - 1] = append; /* replace NUL */ + ret[retlen] = '\0'; /* add NUL */ break; } + ret[retlen++] = escapee; /* duplicate escapee */ + str = found + 1; } return ret; } -static void +/* Returns strlen as a bonus */ +static unsigned replace_char(char *str, char from, char to) { - while ((str = strchr(str, from)) != NULL) - *str++ = to; + char *p = str; + while (*p) { + if (*p == from) + *p = to; + p++; + } + return p - str; } static void -cmdio_write(unsigned status, const char *str) +cmdio_write(uint32_t status_str, const char *str) { + union { + char buf[4]; + uint32_t v32; + } u; char *response; int len; + u.v32 = status_str; + /* FTP allegedly uses telnet protocol for command link. * In telnet, 0xff is an escape char, and needs to be escaped: */ - response = escape_text(utoa(status), str, '\xff', "\xff\xff", '\r'); + response = escape_text(u.buf, str, (0xff << 8) + '\r'); /* ?! does FTP send embedded LFs as NULs? wow */ - len = strlen(response); - replace_char(response, '\n', '\0'); + len = replace_char(response, '\n', '\0'); response[len++] = '\n'; /* tack on trailing '\n' */ xwrite(STDOUT_FILENO, response, len); @@ -215,9 +236,9 @@ handle_pwd(void) cwd = xstrdup(""); /* We have to promote each " to "" */ - response = escape_text(" \"", cwd, '\"', "\"\"", '\"'); + response = escape_text(" \"", cwd, ('"' << 8) + '"'); free(cwd); - cmdio_write(FTP_PWDOK, response); + cmdio_write(STRNUM32(FTP_PWDOK), response); free(response); } @@ -261,21 +282,6 @@ handle_help(void) /* Download commands */ -static void -init_data_sock_params(int sock_fd) -{ - struct linger linger; - - G.data_fd = sock_fd; - - memset(&linger, 0, sizeof(linger)); - linger.l_onoff = 1; - linger.l_linger = 32767; - - setsockopt(sock_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); - setsockopt(sock_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); -} - static int ftpdataio_get_pasv_fd(void) { @@ -288,39 +294,10 @@ ftpdataio_get_pasv_fd(void) return remote_fd; } - init_data_sock_params(remote_fd); - return remote_fd; -} - -static int -ftpdataio_get_port_fd(void) -{ - int remote_fd; - - /* Do we want to die or print error to client? */ - remote_fd = xconnect_stream(G.port_addr); - - init_data_sock_params(remote_fd); + setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); return remote_fd; } -static void -ftpdataio_dispose_transfer_fd(void) -{ - /* This close() blocks because we set SO_LINGER */ - if (G.data_fd > STDOUT_FILENO) { - if (close(G.data_fd) < 0) { - /* Do it again without blocking. */ - struct linger linger; - - memset(&linger, 0, sizeof(linger)); - setsockopt(G.data_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); - close(G.data_fd); - } - } - G.data_fd = -1; -} - static inline int port_active(void) { @@ -341,12 +318,12 @@ get_remote_transfer_fd(const char *p_status_msg) if (pasv_active()) remote_fd = ftpdataio_get_pasv_fd(); else - remote_fd = ftpdataio_get_port_fd(); + remote_fd = xconnect_stream(G.port_addr); if (remote_fd < 0) return remote_fd; - cmdio_write(FTP_DATACONN, p_status_msg); + cmdio_write(STRNUM32(FTP_DATACONN), p_status_msg); return remote_fd; } @@ -374,21 +351,21 @@ port_pasv_cleanup(void) static unsigned bind_for_passive_mode(void) { + int fd; unsigned port; port_pasv_cleanup(); - G.pasv_listen_fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0); - setsockopt_reuseaddr(G.pasv_listen_fd); + G.pasv_listen_fd = fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0); + setsockopt_reuseaddr(fd); set_nport(G.local_addr, 0); - xbind(G.pasv_listen_fd, &G.local_addr->u.sa, G.local_addr->len); - xlisten(G.pasv_listen_fd, 1); - getsockname(G.pasv_listen_fd, &G.local_addr->u.sa, &G.local_addr->len); + xbind(fd, &G.local_addr->u.sa, G.local_addr->len); + xlisten(fd, 1); + getsockname(fd, &G.local_addr->u.sa, &G.local_addr->len); port = get_nport(&G.local_addr->u.sa); port = ntohs(port); - return port; } @@ -487,7 +464,7 @@ handle_retr(void) G.restart_pos = 0; if (!data_transfer_checks_ok()) - return; + return; /* data_transfer_checks_ok emitted error response */ /* O_NONBLOCK is useful if file happens to be a device node */ opened_file = G.ftp_arg ? open(G.ftp_arg, O_RDONLY | O_NONBLOCK) : -1; @@ -520,7 +497,7 @@ handle_retr(void) goto port_pasv_cleanup_out; trans_ret = bb_copyfd_eof(opened_file, remote_fd); - ftpdataio_dispose_transfer_fd(); + close(remote_fd); if (trans_ret < 0) cmdio_write_error(FTP_BADSENDFILE); else @@ -535,185 +512,105 @@ handle_retr(void) /* List commands */ -static char * -statbuf_getperms(const struct stat *statbuf) -{ - char *perms; - enum { r = 'r', w = 'w', x = 'x', s = 's', S = 'S' }; - - perms = xmalloc(11); - memset(perms, '-', 10); - - perms[0] = '?'; - switch (statbuf->st_mode & S_IFMT) { - case S_IFREG: perms[0] = '-'; break; - case S_IFDIR: perms[0] = 'd'; break; - case S_IFLNK: perms[0] = 'l'; break; - case S_IFIFO: perms[0] = 'p'; break; - case S_IFSOCK: perms[0] = s; break; - case S_IFCHR: perms[0] = 'c'; break; - case S_IFBLK: perms[0] = 'b'; break; - } - - if (statbuf->st_mode & S_IRUSR) perms[1] = r; - if (statbuf->st_mode & S_IWUSR) perms[2] = w; - if (statbuf->st_mode & S_IXUSR) perms[3] = x; - if (statbuf->st_mode & S_IRGRP) perms[4] = r; - if (statbuf->st_mode & S_IWGRP) perms[5] = w; - if (statbuf->st_mode & S_IXGRP) perms[6] = x; - if (statbuf->st_mode & S_IROTH) perms[7] = r; - if (statbuf->st_mode & S_IWOTH) perms[8] = w; - if (statbuf->st_mode & S_IXOTH) perms[9] = x; - if (statbuf->st_mode & S_ISUID) perms[3] = (perms[3] == x) ? s : S; - if (statbuf->st_mode & S_ISGID) perms[6] = (perms[6] == x) ? s : S; - if (statbuf->st_mode & S_ISVTX) perms[9] = (perms[9] == x) ? 't' : 'T'; - - perms[10] = '\0'; - - return perms; -} - -static void -write_filestats(int fd, const char *filename, - const struct stat *statbuf) -{ - off_t size; - char *stats, *lnkname = NULL, *perms; - const char *name; - char timestr[32]; - struct tm *tm; - - name = bb_get_last_path_component_nostrip(filename); - - if (statbuf != NULL) { - size = statbuf->st_size; - - if (S_ISLNK(statbuf->st_mode)) - /* Damn symlink... */ - lnkname = xmalloc_readlink(filename); - - tm = gmtime(&statbuf->st_mtime); - if (strftime(timestr, sizeof(timestr), "%b %d %H:%M", tm) == 0) - bb_error_msg_and_die("strftime"); - - timestr[sizeof(timestr) - 1] = '\0'; - - perms = statbuf_getperms(statbuf); - - stats = xasprintf("%s %u\tftp ftp %"OFF_FMT"u\t%s %s", - perms, (int) statbuf->st_nlink, - size, timestr, name); - - free(perms); - } else - stats = xstrdup(name); - - xwrite_str(fd, stats); - free(stats); - if (lnkname != NULL) { - xwrite_str(fd, " -> "); - xwrite_str(fd, lnkname); - free(lnkname); - } - xwrite_str(fd, "\r\n"); -} - -static void -write_dirstats(int fd, const char *dname, int details) +static int +popen_ls(const char *opt) { - DIR *dir; - struct dirent *dirent; - struct stat statbuf; - char *filename; - - dir = xopendir(dname); + char *cwd; + const char *argv[5] = { "ftpd", opt, NULL, G.ftp_arg, NULL }; + struct fd_pair outfd; + pid_t pid; - for (;;) { - dirent = readdir(dir); - if (dirent == NULL) - break; + cwd = xrealloc_getcwd_or_warn(NULL); - /* Ignore . and .. */ - if (dirent->d_name[0] == '.') { - if (dirent->d_name[1] == '\0' - || (dirent->d_name[1] == '.' && dirent->d_name[2] == '\0') - ) { - continue; - } + xpiped_pair(outfd); + + fflush(NULL); + pid = vfork(); + + switch (pid) { + case -1: /* failure */ + bb_perror_msg_and_die("vfork"); + case 0: /* child */ + /* NB: close _first_, then move fds! */ + close(outfd.rd); + xmove_fd(outfd.wr, STDOUT_FILENO); + 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); } - - if (details) { - filename = xasprintf("%s/%s", dname, dirent->d_name); - if (lstat(filename, &statbuf) != 0) { - free(filename); - break; - } - } else - filename = xstrdup(dirent->d_name); - - write_filestats(fd, filename, details ? &statbuf : NULL); - free(filename); + _exit(127); } - - closedir(dir); + /* parent */ + close(outfd.wr); + free(cwd); + return outfd.rd; } static void -handle_dir_common(int full_details, int stat_cmd) +handle_dir_common(int opts) { - int fd; - struct stat statbuf; + FILE *ls_fp; + char *line; + int ls_fd; - if (!stat_cmd && !data_transfer_checks_ok()) - return; + if (!(opts & 1) && !data_transfer_checks_ok()) + return; /* data_transfer_checks_ok emitted error response */ + + ls_fd = popen_ls((opts & 2) ? "-l" : "-1"); + ls_fp = fdopen(ls_fd, "r"); + if (!ls_fp) /* never happens. paranoia */ + bb_perror_msg_and_die("fdopen"); - if (stat_cmd) { - fd = STDIN_FILENO; + if (opts & 1) { + /* STAT */ cmdio_write_raw(STR(FTP_STATFILE_OK)"-Status follows:\r\n"); + while (1) { + line = xmalloc_fgetline(ls_fp); + if (!line) + break; + cmdio_write(0, line); /* hack: 0 results in no status at all */ + free(line); + } + cmdio_write_ok(FTP_STATFILE_OK); } else { - fd = get_remote_transfer_fd(" Here comes the directory listing"); - if (fd < 0) - goto bail; - } - - if (G.ftp_arg) { - if (lstat(G.ftp_arg, &statbuf) != 0) { - /* Dir doesn't exist => return ok to client */ - goto bail; + /* LIST/NLST [] */ + int remote_fd = get_remote_transfer_fd(" Here comes the directory listing"); + if (remote_fd >= 0) { + while (1) { + line = xmalloc_fgetline(ls_fp); + if (!line) + break; + xwrite_str(remote_fd, line); + xwrite(remote_fd, "\r\n", 2); + free(line); + } } - if (S_ISREG(statbuf.st_mode) || S_ISLNK(statbuf.st_mode)) - write_filestats(fd, G.ftp_arg, &statbuf); - else if (S_ISDIR(statbuf.st_mode)) - write_dirstats(fd, G.ftp_arg, full_details); - } else - write_dirstats(fd, ".", full_details); - - bail: - /* Well, if we can't open directory/file it doesn't matter */ - if (!stat_cmd) { - ftpdataio_dispose_transfer_fd(); + close(remote_fd); port_pasv_cleanup(); cmdio_write_ok(FTP_TRANSFEROK); - } else - cmdio_write_ok(FTP_STATFILE_OK); + } + fclose(ls_fp); /* closes ls_fd too */ } - static void handle_list(void) { - handle_dir_common(1, 0); + handle_dir_common(2); } - static void handle_nlst(void) { - handle_dir_common(0, 0); + handle_dir_common(0); } - static void handle_stat_file(void) { - handle_dir_common(1, 1); + handle_dir_common(3); } static void @@ -840,7 +737,7 @@ handle_upload_common(int is_append, int is_unique) goto bail; trans_ret = bb_copyfd_eof(remote_fd, local_file_fd); - ftpdataio_dispose_transfer_fd(); + close(remote_fd); if (trans_ret < 0) cmdio_write_error(FTP_BADSENDFILE); @@ -905,8 +802,19 @@ cmdio_get_cmd_and_arg(void) } int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int ftpd_main(int argc UNUSED_PARAM, char **argv) +int ftpd_main(int argc, char **argv) { + smallint opts; + + opts = getopt32(argv, "l1v" USE_FEATURE_FTP_WRITE("w")); + + if (opts & (OPT_l|OPT_1)) { + /* Our secret backdoor to ls */ + xchdir(argv[2]); + argv[2] = (char*)"--"; + return ls_main(argc, argv); + } + INIT_G(); G.local_addr = get_sock_lsa(STDIN_FILENO); @@ -920,13 +828,13 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) * failure */ } - G.opts = getopt32(argv, "v" USE_FEATURE_FTP_WRITE("w")); - openlog(applet_name, LOG_PID, LOG_DAEMON); logmode |= LOGMODE_SYSLOG; - if (!(G.opts & OPT_v)) + if (!(opts & OPT_v)) logmode = LOGMODE_SYSLOG; + G.proc_self_fd = xopen("/proc/self", O_RDONLY | O_DIRECTORY); + if (argv[optind]) { xchdir(argv[optind]); chroot("."); @@ -1064,7 +972,7 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) else if (cmdval == const_REST) handle_rest(); #if ENABLE_FEATURE_FTP_WRITE - else if (G.opts & OPT_w) { + else if (opts & OPT_w) { if (cmdval == const_STOR) handle_stor(); else if (cmdval == const_MKD) -- 2.25.1