X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fftpd.c;h=e38138c0a85b1b4d8ef0e753597ab323c5113ae9;hb=1f56e51ca1d96b70635eb1b9df1d1ab0edd98a72;hp=ab7308be9a00122eb79512487a92f286414ae4e6;hpb=bf9d17949ee8b5ba8bbfdcd9a78b9a12fb122b63;p=oweals%2Fbusybox.git diff --git a/networking/ftpd.c b/networking/ftpd.c index ab7308be9..e38138c0a 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -4,975 +4,1154 @@ * * Author: Adam Tkac * + * Licensed under GPLv2, see file LICENSE in this source tree. + * * Only subset of FTP protocol is implemented but vast majority of clients - * should not have any problem. You have to run this daemon via inetd. + * should not have any problem. * - * Options: - * -w - enable FTP write commands + * You have to run this daemon via inetd. */ +//usage:#define ftpd_trivial_usage +//usage: "[-wvS] [-t N] [-T N] [DIR]" +//usage:#define ftpd_full_usage "\n\n" +//usage: "Anonymous FTP server\n" +//usage: "\n" +//usage: "ftpd should be used as an inetd service.\n" +//usage: "ftpd's line for inetd.conf:\n" +//usage: " 21 stream tcp nowait root ftpd ftpd /files/to/serve\n" +//usage: "It also can be ran from tcpsvd:\n" +//usage: " tcpsvd -vE 0.0.0.0 21 ftpd /files/to/serve\n" +//usage: "\n -w Allow upload" +//usage: "\n -v Log errors to stderr. -vv: verbose log" +//usage: "\n -S Log errors to syslog. -SS: verbose log" +//usage: "\n -t,-T Idle and absolute timeouts" +//usage: "\n DIR Change root to this directory" + #include "libbb.h" +#include #include +#define FTP_DATACONN 150 +#define FTP_NOOPOK 200 +#define FTP_TYPEOK 200 +#define FTP_PORTOK 200 +#define FTP_STRUOK 200 +#define FTP_MODEOK 200 +#define FTP_ALLOOK 202 +#define FTP_STATOK 211 +#define FTP_STATFILE_OK 213 +#define FTP_HELP 214 +#define FTP_SYSTOK 215 +#define FTP_GREET 220 +#define FTP_GOODBYE 221 +#define FTP_TRANSFEROK 226 +#define FTP_PASVOK 227 +/*#define FTP_EPRTOK 228*/ +#define FTP_EPSVOK 229 +#define FTP_LOGINOK 230 +#define FTP_CWDOK 250 +#define FTP_RMDIROK 250 +#define FTP_DELEOK 250 +#define FTP_RENAMEOK 250 +#define FTP_PWDOK 257 +#define FTP_MKDIROK 257 +#define FTP_GIVEPWORD 331 +#define FTP_RESTOK 350 +#define FTP_RNFROK 350 +#define FTP_TIMEOUT 421 +#define FTP_BADSENDCONN 425 +#define FTP_BADSENDNET 426 +#define FTP_BADSENDFILE 451 +#define FTP_BADCMD 500 +#define FTP_COMMANDNOTIMPL 502 +#define FTP_NEEDUSER 503 +#define FTP_NEEDRNFR 503 +#define FTP_BADSTRU 504 +#define FTP_BADMODE 504 +#define FTP_LOGINERR 530 +#define FTP_FILEFAIL 550 +#define FTP_NOPERM 550 +#define FTP_UPLOADFAIL 553 + +#define STR1(s) #s +#define STR(s) STR1(s) + +/* Convert a constant to 3-digit string, packed into uint32_t */ enum { - FTP_DATACONN = 150, - FTP_NOOPOK = 200, - FTP_TYPEOK = 200, - FTP_PORTOK = 200, - FTP_STRUOK = 200, - FTP_MODEOK = 200, - FTP_ALLOOK = 202, - FTP_STATOK = 211, - FTP_STATFILE_OK = 213, - FTP_HELP = 214, - FTP_SYSTOK = 215, - FTP_GREET = 220, - FTP_GOODBYE = 221, - FTP_TRANSFEROK = 226, - FTP_PASVOK = 227, - FTP_LOGINOK = 230, - FTP_CWDOK = 250, -#if ENABLE_FEATURE_FTP_WRITE - FTP_RMDIROK = 250, - FTP_DELEOK = 250, - FTP_RENAMEOK = 250, -#endif - FTP_PWDOK = 257, -#if ENABLE_FEATURE_FTP_WRITE - FTP_MKDIROK = 257, -#endif - FTP_GIVEPWORD = 331, - FTP_RESTOK = 350, -#if ENABLE_FEATURE_FTP_WRITE - FTP_RNFROK = 350, -#endif - FTP_BADSENDCONN = 425, - FTP_BADSENDNET = 426, - FTP_BADSENDFILE = 451, - FTP_BADCMD = 500, - FTP_COMMANDNOTIMPL = 502, - FTP_NEEDUSER = 503, - FTP_NEEDRNFR = 503, - FTP_BADSTRU = 504, - FTP_BADMODE = 504, - FTP_LOGINERR = 530, - FTP_FILEFAIL = 550, - FTP_NOPERM = 550, - FTP_UPLOADFAIL = 553, - -#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) - const_ALLO = mk_const4('A', 'L', 'L', 'O'), - const_APPE = mk_const4('A', 'P', 'P', 'E'), - const_CDUP = mk_const4('C', 'D', 'U', 'P'), - const_CWD = mk_const3('C', 'W', 'D'), - const_DELE = mk_const4('D', 'E', 'L', 'E'), - const_HELP = mk_const4('H', 'E', 'L', 'P'), - const_LIST = mk_const4('L', 'I', 'S', 'T'), - const_MKD = mk_const3('M', 'K', 'D'), - const_MODE = mk_const4('M', 'O', 'D', 'E'), - const_NLST = mk_const4('N', 'L', 'S', 'T'), - const_NOOP = mk_const4('N', 'O', 'O', 'P'), - const_PASS = mk_const4('P', 'A', 'S', 'S'), - const_PASV = mk_const4('P', 'A', 'S', 'V'), - const_PORT = mk_const4('P', 'O', 'R', 'T'), - const_PWD = mk_const3('P', 'W', 'D'), - const_QUIT = mk_const4('Q', 'U', 'I', 'T'), - const_REST = mk_const4('R', 'E', 'S', 'T'), - const_RETR = mk_const4('R', 'E', 'T', 'R'), - const_RMD = mk_const3('R', 'M', 'D'), - const_RNFR = mk_const4('R', 'N', 'F', 'R'), - const_RNTO = mk_const4('R', 'N', 'T', 'O'), - const_STAT = mk_const4('S', 'T', 'A', 'T'), - const_STOR = mk_const4('S', 'T', 'O', 'R'), - const_STOU = mk_const4('S', 'T', 'O', 'U'), - const_STRU = mk_const4('S', 'T', 'R', 'U'), - const_SYST = mk_const4('S', 'Y', 'S', 'T'), - const_TYPE = mk_const4('T', 'Y', 'P', 'E'), - const_USER = mk_const4('U', 'S', 'E', 'R'), + /* Shift for Nth decimal digit */ + SHIFT2 = 0 * BB_LITTLE_ENDIAN + 24 * BB_BIG_ENDIAN, + SHIFT1 = 8 * BB_LITTLE_ENDIAN + 16 * BB_BIG_ENDIAN, + SHIFT0 = 16 * BB_LITTLE_ENDIAN + 8 * BB_BIG_ENDIAN, + /* And for 4th position (space) */ + SHIFTsp = 24 * BB_LITTLE_ENDIAN + 0 * BB_BIG_ENDIAN, }; +#define STRNUM32(s) (uint32_t)(0 \ + | (('0' + ((s) / 1 % 10)) << SHIFT0) \ + | (('0' + ((s) / 10 % 10)) << SHIFT1) \ + | (('0' + ((s) / 100 % 10)) << SHIFT2) \ +) +#define STRNUM32sp(s) (uint32_t)(0 \ + | (' ' << SHIFTsp) \ + | (('0' + ((s) / 1 % 10)) << SHIFT0) \ + | (('0' + ((s) / 10 % 10)) << SHIFT1) \ + | (('0' + ((s) / 100 % 10)) << SHIFT2) \ +) + +#define MSG_OK "Operation successful\r\n" +#define MSG_ERR "Error\r\n" struct globals { - char *p_control_line_buf; - len_and_sockaddr *local_addr; - len_and_sockaddr *port_addr; int pasv_listen_fd; - int data_fd; +#if !BB_MMU + int root_fd; +#endif + int local_file_fd; + unsigned end_time; + unsigned timeout; + unsigned verbose; + off_t local_file_pos; off_t restart_pos; - char *ftp_cmp; + len_and_sockaddr *local_addr; + len_and_sockaddr *port_addr; + char *ftp_cmd; char *ftp_arg; #if ENABLE_FEATURE_FTP_WRITE char *rnfr_filename; - smallint write_enable; #endif -}; + /* We need these aligned to uint32_t */ + char msg_ok [(sizeof("NNN " MSG_OK ) + 3) & 0xfffc]; + char msg_err[(sizeof("NNN " MSG_ERR) + 3) & 0xfffc]; +} FIX_ALIASING; #define G (*(struct globals*)&bb_common_bufsiz1) -#define INIT_G() do { } while (0) +#define INIT_G() do { \ + /* Moved to main */ \ + /*strcpy(G.msg_ok + 4, MSG_OK );*/ \ + /*strcpy(G.msg_err + 4, MSG_ERR);*/ \ +} while (0) static char * -replace_text(const char *str, const char from, const char *to) +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; + + append = (char)escapee; + escapee >>= 8; - remain = str; remainlen = strlen(str); + retlen = strlen(prepend); + ret = xmalloc(retlen + remainlen * 2 + 1 + 1); + strcpy(ret, prepend); - tolen = strlen(to); + for (;;) { + found = strchrnul(str, escapee); + chunklen = found - str + 1; - /* simply alloc strlen(str)*strlen(to). To is max 2 so it's allowed */ - ret = xmalloc(remainlen * strlen(to) + 1); - retlen = 0; + /* Copy chunk up to and including escapee (or NUL) to ret */ + memcpy(ret + retlen, str, chunklen); + retlen += chunklen; - for (;;) { - found = strchr(remain, from); - if (found != NULL) { - chunklen = found - remain; - - /* Copy chunk which doesn't contain 'from' to ret */ - memcpy(&ret[retlen], remain, chunklen); - retlen += chunklen; - - /* Now copy 'to' instead of 'from' */ - memcpy(&ret[retlen], to, tolen); - retlen += tolen; - - remain = found + 1; - } else { - /* - * The last chunk. We are already sure that we have enough space - * so we can use strcpy. - */ - strcpy(&ret[retlen], remain); + 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) { - char *ptr; - - /* Don't use strchr here...*/ - while ((ptr = strchr(str, from)) != NULL) { - *ptr = to; - str = ptr + 1; + char *p = str; + while (*p) { + if (*p == from) + *p = to; + p++; } + return p - str; } static void -str_netfd_write(const char *str, int fd) +verbose_log(const char *str) { - xwrite(fd, str, strlen(str)); + bb_error_msg("%.*s", (int)strcspn(str, "\r\n"), str); } +/* NB: status_str is char[4] packed into uint32_t */ static void -ftp_write_str_common(unsigned int status, const char *str, char sep) +cmdio_write(uint32_t status_str, const char *str) { - char *escaped_str, *response; - size_t len; - - escaped_str = replace_text(str, '\377', "\377\377"); + char *response; + int len; - response = xasprintf("%u%c%s\r\n", status, sep, escaped_str); - free(escaped_str); + /* FTP uses telnet protocol for command link. + * In telnet, 0xff is an escape char, and needs to be escaped: */ + response = escape_text((char *) &status_str, str, (0xff << 8) + '\r'); - len = strlen(response); - replace_char(escaped_str, '\n', '\0'); + /* FTP sends embedded LFs as NULs */ + len = replace_char(response, '\n', '\0'); - /* Change trailing '\0' back to '\n' */ - response[len - 1] = '\n'; - xwrite(STDIN_FILENO, response, len); + response[len++] = '\n'; /* tack on trailing '\n' */ + xwrite(STDOUT_FILENO, response, len); + if (G.verbose > 1) + verbose_log(response); + free(response); } static void -cmdio_write(int status, const char *p_text) +cmdio_write_ok(unsigned status) { - ftp_write_str_common(status, p_text, ' '); + *(uint32_t *) G.msg_ok = status; + xwrite(STDOUT_FILENO, G.msg_ok, sizeof("NNN " MSG_OK) - 1); + if (G.verbose > 1) + verbose_log(G.msg_ok); } +#define WRITE_OK(a) cmdio_write_ok(STRNUM32sp(a)) +/* TODO: output strerr(errno) if errno != 0? */ static void -cmdio_write_hyphen(int status, const char *p_text) +cmdio_write_error(unsigned status) { - ftp_write_str_common(status, p_text, '-'); + *(uint32_t *) G.msg_err = status; + xwrite(STDOUT_FILENO, G.msg_err, sizeof("NNN " MSG_ERR) - 1); + if (G.verbose > 0) + verbose_log(G.msg_err); } +#define WRITE_ERR(a) cmdio_write_error(STRNUM32sp(a)) static void cmdio_write_raw(const char *p_text) { - str_netfd_write(p_text, STDIN_FILENO); + xwrite_str(STDOUT_FILENO, p_text); + if (G.verbose > 1) + verbose_log(p_text); } -static uint32_t -cmdio_get_cmd_and_arg(void) +static void +timeout_handler(int sig UNUSED_PARAM) { - int len; - uint32_t cmdval; - char *cmd; + off_t pos; + int sv_errno = errno; - free(G.ftp_cmp); - G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, NULL); -/* - * TODO: - * - * now we should change all '\0' to '\n' - xmalloc_reads will be improved, - * probably - */ - len = strlen(cmd) - 1; - while (len >= 0 && cmd[len] == '\r') { - cmd[len] = '\0'; - len--; - } + if ((int)(monotonic_sec() - G.end_time) >= 0) + goto timed_out; - G.ftp_arg = strchr(cmd, ' '); - if (G.ftp_arg != NULL) { - *G.ftp_arg = '\0'; - G.ftp_arg++; - } - cmdval = 0; - while (*cmd) - cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20); + if (!G.local_file_fd) + goto timed_out; - return cmdval; + pos = xlseek(G.local_file_fd, 0, SEEK_CUR); + if (pos == G.local_file_pos) + goto timed_out; + G.local_file_pos = pos; + + alarm(G.timeout); + errno = sv_errno; + return; + + timed_out: + cmdio_write_raw(STR(FTP_TIMEOUT)" Timeout\r\n"); +/* TODO: do we need to abort (as opposed to usual shutdown) data transfer? */ + exit(1); } +/* Simple commands */ + static void -init_data_sock_params(int sock_fd) +handle_pwd(void) { - struct linger linger; + char *cwd, *response; - G.data_fd = sock_fd; - - memset(&linger, 0, sizeof(linger)); - linger.l_onoff = 1; - linger.l_linger = 32767; + cwd = xrealloc_getcwd_or_warn(NULL); + if (cwd == NULL) + cwd = xstrdup(""); - setsockopt(sock_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); - setsockopt(sock_fd, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); + /* We have to promote each " to "" */ + response = escape_text(" \"", cwd, ('"' << 8) + '"'); + free(cwd); + cmdio_write(STRNUM32(FTP_PWDOK), response); + free(response); } -static int -ftpdataio_get_pasv_fd(void) +static void +handle_cwd(void) { - int remote_fd; - - remote_fd = accept(G.pasv_listen_fd, NULL, 0); - - if (remote_fd < 0) { - cmdio_write(FTP_BADSENDCONN, "Can't establish connection"); - return remote_fd; + if (!G.ftp_arg || chdir(G.ftp_arg) != 0) { + WRITE_ERR(FTP_FILEFAIL); + return; } - - init_data_sock_params(remote_fd); - return remote_fd; + WRITE_OK(FTP_CWDOK); } -static int -ftpdataio_get_port_fd(void) +static void +handle_cdup(void) { - int remote_fd; - - /* Do we want die or print error to client? */ - remote_fd = xconnect_stream(G.port_addr); + G.ftp_arg = (char*)".."; + handle_cwd(); +} - init_data_sock_params(remote_fd); - return remote_fd; +static void +handle_stat(void) +{ + cmdio_write_raw(STR(FTP_STATOK)"-Server status:\r\n" + " TYPE: BINARY\r\n" + STR(FTP_STATOK)" Ok\r\n"); } +/* Examples of HELP and FEAT: +# nc -vvv ftp.kernel.org 21 +ftp.kernel.org (130.239.17.4:21) open +220 Welcome to ftp.kernel.org. +FEAT +211-Features: + EPRT + EPSV + MDTM + PASV + REST STREAM + SIZE + TVFS + UTF8 +211 End +HELP +214-The following commands are recognized. + ABOR ACCT ALLO APPE CDUP CWD DELE EPRT EPSV FEAT HELP LIST MDTM MKD + MODE NLST NOOP OPTS PASS PASV PORT PWD QUIT REIN REST RETR RMD RNFR + RNTO SITE SIZE SMNT STAT STOR STOU STRU SYST TYPE USER XCUP XCWD XMKD + XPWD XRMD +214 Help OK. +*/ static void -ftpdataio_dispose_transfer_fd(void) +handle_feat(unsigned status) { - /* 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; + cmdio_write(status, "-Features:"); + cmdio_write_raw(" EPSV\r\n" + " PASV\r\n" + " REST STREAM\r\n" + " MDTM\r\n" + " SIZE\r\n"); + cmdio_write(status, " Ok"); } -static int +/* Download commands */ + +static inline int port_active(void) { - return (G.port_addr != NULL) ? 1: 0; + return (G.port_addr != NULL); } -static int +static inline int pasv_active(void) { - return (G.pasv_listen_fd != -1) ? 1 : 0; + return (G.pasv_listen_fd > STDOUT_FILENO); } +static void +port_pasv_cleanup(void) +{ + free(G.port_addr); + G.port_addr = NULL; + if (G.pasv_listen_fd > STDOUT_FILENO) + close(G.pasv_listen_fd); + G.pasv_listen_fd = -1; +} + +/* On error, emits error code to the peer */ static int -get_remote_transfer_fd(const char *p_status_msg) +ftpdataio_get_pasv_fd(void) { int remote_fd; - if (pasv_active()) - remote_fd = ftpdataio_get_pasv_fd(); - else - remote_fd = ftpdataio_get_port_fd(); + remote_fd = accept(G.pasv_listen_fd, NULL, 0); - if (remote_fd < 0) + if (remote_fd < 0) { + WRITE_ERR(FTP_BADSENDCONN); return remote_fd; + } - cmdio_write(FTP_DATACONN, p_status_msg); + setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); return remote_fd; } -static void -handle_pwd(void) +/* Clears port/pasv data. + * This means we dont waste resources, for example, keeping + * PASV listening socket open when it is no longer needed. + * On error, emits error code to the peer (or exits). + * On success, emits p_status_msg to the peer. + */ +static int +get_remote_transfer_fd(const char *p_status_msg) { - char *cwd, *promoted_cwd, *response; - - cwd = xrealloc_getcwd_or_warn(NULL); - if (cwd == NULL) - cwd = xstrdup(""); + int remote_fd; - /* We _have to_ promote each " to "" */ - promoted_cwd = replace_text(cwd, '\"', "\"\""); - free(cwd); - response = xasprintf("\"%s\"", promoted_cwd); - free(promoted_cwd); - cmdio_write(FTP_PWDOK, response); - free(response); -} + if (pasv_active()) + /* On error, emits error code to the peer */ + remote_fd = ftpdataio_get_pasv_fd(); + else + /* Exits on error */ + remote_fd = xconnect_stream(G.port_addr); -static void -handle_cwd(void) -{ - int retval; + port_pasv_cleanup(); - /* XXX Do we need check ftp_arg != NULL? */ - retval = chdir(G.ftp_arg); - if (retval == 0) - cmdio_write(FTP_CWDOK, "Directory changed"); - else - cmdio_write(FTP_FILEFAIL, "Can't change directory"); -} + if (remote_fd < 0) + return remote_fd; -static void -handle_cdup(void) -{ - G.ftp_arg = xstrdup(".."); - handle_cwd(); - free(G.ftp_arg); + cmdio_write(STRNUM32(FTP_DATACONN), p_status_msg); + return remote_fd; } +/* If there were neither PASV nor PORT, emits error code to the peer */ static int -data_transfer_checks_ok(void) +port_or_pasv_was_seen(void) { if (!pasv_active() && !port_active()) { - cmdio_write(FTP_BADSENDCONN, "Use PORT or PASV first"); + cmdio_write_raw(STR(FTP_BADSENDCONN)" Use PORT/PASV first\r\n"); return 0; } return 1; } -static void -port_cleanup(void) +/* Exits on error */ +static unsigned +bind_for_passive_mode(void) { - if (G.port_addr != NULL) - free(G.port_addr); + int fd; + unsigned port; - G.port_addr = NULL; -} + port_pasv_cleanup(); -static void -pasv_cleanup(void) -{ - if (G.pasv_listen_fd > STDOUT_FILENO) - close(G.pasv_listen_fd); - G.pasv_listen_fd = -1; -} + G.pasv_listen_fd = fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0); + setsockopt_reuseaddr(fd); -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; - } + set_nport(&G.local_addr->u.sa, 0); + 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); - 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; + port = get_nport(&G.local_addr->u.sa); + port = ntohs(port); + return port; } +/* Exits on error */ static void -write_filestats(int fd, const char *filename, - const struct stat *statbuf) +handle_pasv(void) { - off_t size; - char *stats, *lnkname = NULL, *perms; - const char *name; - int retval; - char timestr[32]; - struct tm *tm; - const char *format = "%b %d %H:%M"; - - 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); - retval = strftime(timestr, sizeof(timestr), format, tm); - if (retval == 0) - bb_error_msg_and_die("strftime"); - - timestr[sizeof(timestr) - 1] = '\0'; + unsigned port; + char *addr, *response; - perms = statbuf_getperms(statbuf); + port = bind_for_passive_mode(); - stats = xasprintf("%s %u\tftp ftp %"OFF_FMT"u\t%s %s", - perms, (int) statbuf->st_nlink, - size, timestr, name); + if (G.local_addr->u.sa.sa_family == AF_INET) + addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa); + else /* seen this in the wild done by other ftp servers: */ + addr = xstrdup("0.0.0.0"); + replace_char(addr, '.', ','); - free(perms); - } else - stats = xstrdup(name); - - str_netfd_write(stats, fd); - free(stats); - if (lnkname != NULL) { - str_netfd_write(" -> ", fd); - str_netfd_write(lnkname, fd); - free(lnkname); - } - str_netfd_write("\r\n", fd); + response = xasprintf(STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n", + addr, (int)(port >> 8), (int)(port & 255)); + free(addr); + cmdio_write_raw(response); + free(response); } +/* Exits on error */ static void -write_dirstats(int fd, const char *dname, int details) +handle_epsv(void) { - DIR *dir; - struct dirent *dirent; - struct stat statbuf; - char *filename; + unsigned port; + char *response; - dir = xopendir(dname); + port = bind_for_passive_mode(); + response = xasprintf(STR(FTP_EPSVOK)" EPSV ok (|||%u|)\r\n", port); + cmdio_write_raw(response); + free(response); +} - for (;;) { - dirent = readdir(dir); - if (dirent == NULL) - break; +static void +handle_port(void) +{ + unsigned port, port_hi; + char *raw, *comma; +#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES + socklen_t peer_ipv4_len; + struct sockaddr_in peer_ipv4; + struct in_addr port_ipv4_sin_addr; +#endif - /* Ignore . and .. */ - if (dirent->d_name[0] == '.') { - if (dirent->d_name[1] == '\0' - || (dirent->d_name[1] == '.' && dirent->d_name[2] == '\0') - ) { - continue; - } - } + port_pasv_cleanup(); - if (details) { - filename = xasprintf("%s/%s", dname, dirent->d_name); - if (lstat(filename, &statbuf) != 0) { - free(filename); - goto bail; - } - } else - filename = xstrdup(dirent->d_name); + raw = G.ftp_arg; - write_filestats(fd, filename, details ? &statbuf : NULL); - free(filename); + /* PORT command format makes sense only over IPv4 */ + if (!raw +#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES + || G.local_addr->u.sa.sa_family != AF_INET +#endif + ) { + bail: + WRITE_ERR(FTP_BADCMD); + return; } -bail: - closedir(dir); -} - -static void -handle_pasv(void) -{ - int bind_retries = 10; - unsigned short port; - enum { min_port = 1024, max_port = 65535 }; - char *addr, *wire_addr, *response; - - pasv_cleanup(); - port_cleanup(); - G.pasv_listen_fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0); - setsockopt_reuseaddr(G.pasv_listen_fd); - - /* TODO bind() with port == 0 and then call getsockname */ - while (--bind_retries) { - port = rand() % max_port; - if (port < min_port) { - port += min_port; - } + comma = strrchr(raw, ','); + if (comma == NULL) + goto bail; + *comma = '\0'; + port = bb_strtou(&comma[1], NULL, 10); + if (errno || port > 0xff) + goto bail; - set_nport(G.local_addr, htons(port)); - /* We don't want to use xbind, it'll die if port is in use */ - if (bind(G.pasv_listen_fd, &G.local_addr->u.sa, G.local_addr->len) != 0) { - /* do we want check if errno == EADDRINUSE ? */ - continue; - } - xlisten(G.pasv_listen_fd, 1); - break; - } + comma = strrchr(raw, ','); + if (comma == NULL) + goto bail; + *comma = '\0'; + port_hi = bb_strtou(&comma[1], NULL, 10); + if (errno || port_hi > 0xff) + goto bail; + port |= port_hi << 8; - if (!bind_retries) - bb_error_msg_and_die("can't create pasv socket"); +#ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES + replace_char(raw, ',', '.'); - addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa); - wire_addr = replace_text(addr, '.', ","); - free(addr); + /* We are verifying that PORT's IP matches getpeername(). + * Otherwise peer can make us open data connections + * to other hosts (security problem!) + * This code would be too simplistic: + * lsa = xdotted2sockaddr(raw, port); + * if (lsa == NULL) goto bail; + */ + if (!inet_aton(raw, &port_ipv4_sin_addr)) + goto bail; + peer_ipv4_len = sizeof(peer_ipv4); + if (getpeername(STDIN_FILENO, &peer_ipv4, &peer_ipv4_len) != 0) + goto bail; + if (memcmp(&port_ipv4_sin_addr, &peer_ipv4.sin_addr, sizeof(struct in_addr)) != 0) + goto bail; - response = xasprintf("Entering Passive Mode (%s,%u,%u)", - wire_addr, (int)(port >> 8), (int)(port & 255)); + G.port_addr = xdotted2sockaddr(raw, port); +#else + G.port_addr = get_peer_lsa(STDIN_FILENO); + set_nport(&G.port_addr->u.sa, htons(port)); +#endif + WRITE_OK(FTP_PORTOK); +} - cmdio_write(FTP_PASVOK, response); - free(wire_addr); - free(response); +static void +handle_rest(void) +{ + /* When ftp_arg == NULL simply restart from beginning */ + G.restart_pos = G.ftp_arg ? xatoi_positive(G.ftp_arg) : 0; + WRITE_OK(FTP_RESTOK); } static void handle_retr(void) { struct stat statbuf; - int trans_ret, retval; + off_t bytes_transferred; int remote_fd; - int opened_file; + int local_file_fd; off_t offset = G.restart_pos; char *response; G.restart_pos = 0; - if (!data_transfer_checks_ok()) - return; + if (!port_or_pasv_was_seen()) + return; /* port_or_pasv_was_seen emitted error response */ - /* XXX Do we need check if ftp_arg != NULL? */ - opened_file = open(G.ftp_arg, O_RDONLY | O_NONBLOCK); - if (opened_file < 0) { - cmdio_write(FTP_FILEFAIL, "Can't open file"); + /* O_NONBLOCK is useful if file happens to be a device node */ + local_file_fd = G.ftp_arg ? open(G.ftp_arg, O_RDONLY | O_NONBLOCK) : -1; + if (local_file_fd < 0) { + WRITE_ERR(FTP_FILEFAIL); return; } - retval = fstat(opened_file, &statbuf); - if (retval < 0 || !S_ISREG(statbuf.st_mode)) { + if (fstat(local_file_fd, &statbuf) != 0 || !S_ISREG(statbuf.st_mode)) { /* Note - pretend open failed */ - cmdio_write(FTP_FILEFAIL, "Can't open file"); + WRITE_ERR(FTP_FILEFAIL); goto file_close_out; } + G.local_file_fd = local_file_fd; - /* Now deactive O_NONBLOCK, otherwise we have a problem on DMAPI filesystems - * such as XFS DMAPI. + /* Now deactive O_NONBLOCK, otherwise we have a problem + * on DMAPI filesystems such as XFS DMAPI. */ - ndelay_off(opened_file); + ndelay_off(local_file_fd); /* Set the download offset (from REST) if any */ if (offset != 0) - xlseek(opened_file, offset, SEEK_SET); + xlseek(local_file_fd, offset, SEEK_SET); response = xasprintf( - "Opening BINARY mode data connection for (%s %"OFF_FMT"u bytes).", + " Opening BINARY connection for %s (%"OFF_FMT"u bytes)", G.ftp_arg, statbuf.st_size); - remote_fd = get_remote_transfer_fd(response); free(response); if (remote_fd < 0) - goto port_pasv_cleanup_out; + goto file_close_out; - trans_ret = bb_copyfd_eof(opened_file, remote_fd); - ftpdataio_dispose_transfer_fd(); - if (trans_ret < 0) - cmdio_write(FTP_BADSENDFILE, "Error sending local file"); + bytes_transferred = bb_copyfd_eof(local_file_fd, remote_fd); + close(remote_fd); + if (bytes_transferred < 0) + WRITE_ERR(FTP_BADSENDFILE); else - cmdio_write(FTP_TRANSFEROK, "File sent OK"); + WRITE_OK(FTP_TRANSFEROK); -port_pasv_cleanup_out: - port_cleanup(); - pasv_cleanup(); -file_close_out: - close(opened_file); + file_close_out: + close(local_file_fd); + G.local_file_fd = 0; } -static void -handle_dir_common(int full_details, int stat_cmd) -{ - int fd; - struct stat statbuf; +/* List commands */ - if (!stat_cmd && !data_transfer_checks_ok()) - return; +static int +popen_ls(const char *opt) +{ + const char *argv[5]; + struct fd_pair outfd; + pid_t pid; + + argv[0] = "ftpd"; + argv[1] = opt; /* "-l" or "-1" */ +#if BB_MMU + argv[2] = "--"; +#else + /* NOMMU ftpd ls helper chdirs to argv[2], + * preventing peer from seeing real root. */ + argv[2] = xrealloc_getcwd_or_warn(NULL); +#endif + argv[3] = G.ftp_arg; + argv[4] = NULL; + + /* Improve compatibility with non-RFC conforming FTP clients + * which send e.g. "LIST -l", "LIST -la", "LIST -aL". + * See https://bugs.kde.org/show_bug.cgi?id=195578 */ + if (ENABLE_FEATURE_FTPD_ACCEPT_BROKEN_LIST + && G.ftp_arg && G.ftp_arg[0] == '-' + ) { + const char *tmp = strchr(G.ftp_arg, ' '); + if (tmp) /* skip the space */ + tmp++; + argv[3] = tmp; + } - if (stat_cmd) { - fd = STDIN_FILENO; - cmdio_write_hyphen(FTP_STATFILE_OK, "Status follows:"); - } else { - fd = get_remote_transfer_fd("Here comes the directory listing"); - if (fd < 0) - goto bail; + xpiped_pair(outfd); + + /*fflush_all(); - so far we dont use stdio on output */ + pid = BB_MMU ? xfork() : xvfork(); + if (pid == 0) { + /* child */ +#if !BB_MMU + /* On NOMMU, we want to execute a child - copy of ourself. + * In chroot we usually can't do it. Thus we chdir + * out of the chroot back to original root, + * and (see later below) execute bb_busybox_exec_path + * relative to current directory */ + if (fchdir(G.root_fd) != 0) + _exit(127); + /*close(G.root_fd); - close_on_exec_on() took care of this */ +#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); + dup(STDOUT_FILENO); /* copy will become STDIN_FILENO */ +#if BB_MMU + /* memset(&G, 0, sizeof(G)); - ls_main does it */ + exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv)); +#else + /* + 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(bb_busybox_exec_path + 1, (char**) argv); + _exit(127); +#endif } - if (G.ftp_arg != NULL) { - if (lstat(G.ftp_arg, &statbuf) != 0) { - /* Dir doesn't exist => return ok to client */ - goto bail; - } - 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(); - pasv_cleanup(); - port_cleanup(); - cmdio_write(FTP_TRANSFEROK, "OK"); - } else - cmdio_write(FTP_STATFILE_OK, "End of status"); + /* parent */ + close(outfd.wr); +#if !BB_MMU + free((char*)argv[2]); +#endif + return outfd.rd; } +enum { + USE_CTRL_CONN = 1, + LONG_LISTING = 2, +}; + +static void +handle_dir_common(int opts) +{ + FILE *ls_fp; + char *line; + int ls_fd; + + if (!(opts & USE_CTRL_CONN) && !port_or_pasv_was_seen()) + return; /* port_or_pasv_was_seen emitted error response */ + + /* -n prevents user/groupname display, + * which can be problematic in chroot */ + ls_fd = popen_ls((opts & LONG_LISTING) ? "-l" : "-1"); + ls_fp = xfdopen_for_read(ls_fd); + + if (opts & USE_CTRL_CONN) { + /* STAT */ + cmdio_write_raw(STR(FTP_STATFILE_OK)"-File status:\r\n"); + while (1) { + line = xmalloc_fgetline(ls_fp); + if (!line) + break; + /* Hack: 0 results in no status at all */ + /* Note: it's ok that we don't prepend space, + * ftp.kernel.org doesn't do that too */ + cmdio_write(0, line); + free(line); + } + WRITE_OK(FTP_STATFILE_OK); + } else { + /* LIST/NLST [] */ + int remote_fd = get_remote_transfer_fd(" Directory listing"); + if (remote_fd >= 0) { + while (1) { + line = xmalloc_fgetline(ls_fp); + if (!line) + break; + /* I've seen clients complaining when they + * are fed with ls output with bare '\n'. + * Pity... that would be much simpler. + */ +/* TODO: need to s/LF/NUL/g here */ + xwrite_str(remote_fd, line); + xwrite(remote_fd, "\r\n", 2); + free(line); + } + } + close(remote_fd); + WRITE_OK(FTP_TRANSFEROK); + } + fclose(ls_fp); /* closes ls_fd too */ +} static void handle_list(void) { - handle_dir_common(1, 0); + handle_dir_common(LONG_LISTING); } - static void -handle_type(void) +handle_nlst(void) { - if (G.ftp_arg - && ( ((G.ftp_arg[0] | 0x20) == 'i' && G.ftp_arg[1] == '\0') - || !strcasecmp(G.ftp_arg, "L8") - || !strcasecmp(G.ftp_arg, "L 8") - ) - ) { - cmdio_write(FTP_TYPEOK, "Switching to Binary mode"); - } else { - cmdio_write(FTP_BADCMD, "Unrecognised TYPE command"); - } + /* NLST returns list of names, "\r\n" terminated without regard + * to the current binary flag. Names may start with "/", + * then they represent full names (we don't produce such names), + * otherwise names are relative to current directory. + * Embedded "\n" are replaced by NULs. This is safe since names + * can never contain NUL. + */ + handle_dir_common(0); } - static void -handle_port(void) +handle_stat_file(void) { - unsigned short port; - char *raw = NULL, *port_part; - len_and_sockaddr *lsa = NULL; - - pasv_cleanup(); - port_cleanup(); - - if (G.ftp_arg == NULL) - goto bail; - - raw = replace_text(G.ftp_arg, ',', "."); - - port_part = strrchr(raw, '.'); - if (port_part == NULL) - goto bail; - - port = xatou16(&port_part[1]); - *port_part = '\0'; - - port_part = strrchr(raw, '.'); - if (port_part == NULL) - goto bail; - - port |= xatou16(&port_part[1]) << 8; - *port_part = '\0'; - - lsa = xdotted2sockaddr(raw, port); - -bail: - free(raw); - - if (lsa == NULL) { - cmdio_write(FTP_BADCMD, "Illegal PORT command"); - return; - } - - G.port_addr = lsa; - cmdio_write(FTP_PORTOK, "PORT command successful. Consider using PASV"); + handle_dir_common(LONG_LISTING + USE_CTRL_CONN); } -#if ENABLE_FEATURE_FTP_WRITE +/* This can be extended to handle MLST, as all info is available + * in struct stat for that: + * MLST file_name + * 250-Listing file_name + * type=file;size=4161;modify=19970214165800; /dir/dir/file_name + * 250 End + * Nano-doc: + * MLST [] + * Returned name should be either the same as requested, or fully qualified. + * If there was no parameter, return "" or (preferred) fully-qualified name. + * Returned "facts" (case is not important): + * size - size in octets + * modify - last modification time + * type - entry type (file,dir,OS.unix=block) + * (+ cdir and pdir types for MLSD) + * unique - unique id of file/directory (inode#) + * perm - + * a: can be appended to (APPE) + * d: can be deleted (RMD/DELE) + * f: can be renamed (RNFR) + * r: can be read (RETR) + * w: can be written (STOR) + * e: can CWD into this dir + * l: this dir can be listed (dir only!) + * c: can create files in this dir + * m: can create dirs in this dir (MKD) + * p: can delete files in this dir + * UNIX.mode - unix file mode + */ static void -handle_upload_common(int is_append, int is_unique) +handle_size_or_mdtm(int need_size) { - char *template = NULL; - int trans_ret; - int new_file_fd; - int remote_fd; - - enum { - fileflags = O_CREAT | O_WRONLY | O_APPEND, - }; - - off_t offset = G.restart_pos; - - G.restart_pos = 0; - if (!data_transfer_checks_ok()) - return; - - if (is_unique) { - template = xstrdup("uniq.XXXXXX"); - /* - * XXX Use mkostemp here? vsftpd opens file with O_CREAT, O_WRONLY, - * O_APPEND and O_EXCL flags... - */ - new_file_fd = mkstemp(template); - } else { - /* XXX Do we need check if ftp_arg != NULL? */ - if (!is_append && offset == 0) - new_file_fd = open(G.ftp_arg, O_CREAT | O_WRONLY | O_APPEND | O_NONBLOCK | O_TRUNC, 0666); - else - new_file_fd = open(G.ftp_arg, O_CREAT | O_WRONLY | O_APPEND | O_NONBLOCK, 0666); - } - - if (new_file_fd < 0) { - cmdio_write(FTP_UPLOADFAIL, "Can't create file"); + struct stat statbuf; + struct tm broken_out; + char buf[(sizeof("NNN %"OFF_FMT"u\r\n") + sizeof(off_t) * 3) + | sizeof("NNN YYYYMMDDhhmmss\r\n") + ]; + + if (!G.ftp_arg + || stat(G.ftp_arg, &statbuf) != 0 + || !S_ISREG(statbuf.st_mode) + ) { + WRITE_ERR(FTP_FILEFAIL); return; } - - if (!is_append && offset != 0) { - /* warning, allows seek past end of file! Check for seek > size? */ - xlseek(new_file_fd, offset, SEEK_SET); + if (need_size) { + sprintf(buf, STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n", statbuf.st_size); + } else { + gmtime_r(&statbuf.st_mtime, &broken_out); + sprintf(buf, STR(FTP_STATFILE_OK)" %04u%02u%02u%02u%02u%02u\r\n", + broken_out.tm_year + 1900, + broken_out.tm_mon, + broken_out.tm_mday, + broken_out.tm_hour, + broken_out.tm_min, + broken_out.tm_sec); } - - if (is_unique) { - char *resp = xasprintf("FILE: %s", template); - remote_fd = get_remote_transfer_fd(resp); - free(resp); - free(template); - } else - remote_fd = get_remote_transfer_fd("Ok to send data"); - - if (remote_fd < 0) - goto bail; - - trans_ret = bb_copyfd_eof(remote_fd, new_file_fd); - ftpdataio_dispose_transfer_fd(); - - if (trans_ret < 0) - cmdio_write(FTP_BADSENDFILE, "Failure writing to local file"); - else - cmdio_write(FTP_TRANSFEROK, "File receive OK"); - -bail: - port_cleanup(); - pasv_cleanup(); - close(new_file_fd); + cmdio_write_raw(buf); } -static void -handle_stor(void) -{ - handle_upload_common(0, 0); -} +/* Upload commands */ +#if ENABLE_FEATURE_FTP_WRITE static void handle_mkd(void) { - int retval; - - /* Do we need check if ftp_arg != NULL? */ - retval = mkdir(G.ftp_arg, 0770); - if (retval != 0) { - cmdio_write(FTP_FILEFAIL, "Create directory operation failed"); + if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) { + WRITE_ERR(FTP_FILEFAIL); return; } - - cmdio_write(FTP_MKDIROK, "created"); + WRITE_OK(FTP_MKDIROK); } static void handle_rmd(void) { - int retval; - - /* Do we need check if ftp_arg != NULL? */ - retval = rmdir(G.ftp_arg); - if (retval != 0) - cmdio_write(FTP_FILEFAIL, "rmdir failed"); - else - cmdio_write(FTP_RMDIROK, "rmdir successful"); + if (!G.ftp_arg || rmdir(G.ftp_arg) != 0) { + WRITE_ERR(FTP_FILEFAIL); + return; + } + WRITE_OK(FTP_RMDIROK); } static void handle_dele(void) { - int retval; - - /* Do we need check if ftp_arg != NULL? */ - retval = unlink(G.ftp_arg); - if (retval != 0) - cmdio_write(FTP_FILEFAIL, "Delete failed"); - else - cmdio_write(FTP_DELEOK, "Delete successful"); + if (!G.ftp_arg || unlink(G.ftp_arg) != 0) { + WRITE_ERR(FTP_FILEFAIL); + return; + } + WRITE_OK(FTP_DELEOK); } -#endif /* ENABLE_FEATURE_FTP_WRITE */ static void -handle_rest(void) +handle_rnfr(void) { - /* When ftp_arg == NULL simply restart from beginning */ - G.restart_pos = xatoi_u(G.ftp_arg); - cmdio_write(FTP_RESTOK, "Restart OK"); + free(G.rnfr_filename); + G.rnfr_filename = xstrdup(G.ftp_arg); + WRITE_OK(FTP_RNFROK); } -#if ENABLE_FEATURE_FTP_WRITE static void -handle_rnfr(void) +handle_rnto(void) { - struct stat statbuf; int retval; - /* Clear old value */ + /* If we didn't get a RNFR, throw a wobbly */ + if (G.rnfr_filename == NULL || G.ftp_arg == NULL) { + cmdio_write_raw(STR(FTP_NEEDRNFR)" Use RNFR first\r\n"); + return; + } + + retval = rename(G.rnfr_filename, G.ftp_arg); free(G.rnfr_filename); + G.rnfr_filename = NULL; - /* Does it exist? Do we need check if ftp_arg != NULL? */ - retval = stat(G.ftp_arg, &statbuf); - if (retval == 0) { - /* Yes */ - G.rnfr_filename = xstrdup(G.ftp_arg); - cmdio_write(FTP_RNFROK, "Ready for RNTO"); - } else - cmdio_write(FTP_FILEFAIL, "RNFR command failed"); + if (retval) { + WRITE_ERR(FTP_FILEFAIL); + return; + } + WRITE_OK(FTP_RENAMEOK); } static void -handle_rnto(void) +handle_upload_common(int is_append, int is_unique) { - int retval; + struct stat statbuf; + char *tempname; + off_t bytes_transferred; + off_t offset; + int local_file_fd; + int remote_fd; - /* If we didn't get a RNFR, throw a wobbly */ - if (G.rnfr_filename == NULL) { - cmdio_write(FTP_NEEDRNFR, "RNFR required first"); + offset = G.restart_pos; + G.restart_pos = 0; + + if (!port_or_pasv_was_seen()) + return; /* port_or_pasv_was_seen emitted error response */ + + tempname = NULL; + local_file_fd = -1; + if (is_unique) { + tempname = xstrdup(" FILE: uniq.XXXXXX"); + local_file_fd = mkstemp(tempname + 7); + } else if (G.ftp_arg) { + int flags = O_WRONLY | O_CREAT | O_TRUNC; + if (is_append) + flags = O_WRONLY | O_CREAT | O_APPEND; + if (offset) + flags = O_WRONLY | O_CREAT; + local_file_fd = open(G.ftp_arg, flags, 0666); + } + + if (local_file_fd < 0 + || fstat(local_file_fd, &statbuf) != 0 + || !S_ISREG(statbuf.st_mode) + ) { + WRITE_ERR(FTP_UPLOADFAIL); + if (local_file_fd >= 0) + goto close_local_and_bail; return; } + G.local_file_fd = local_file_fd; - /* XXX Do we need check if ftp_arg != NULL? */ - retval = rename(G.rnfr_filename, G.ftp_arg); + if (offset) + xlseek(local_file_fd, offset, SEEK_SET); - free(G.rnfr_filename); + remote_fd = get_remote_transfer_fd(tempname ? tempname : " Ok to send data"); + free(tempname); - if (retval == 0) - cmdio_write(FTP_RENAMEOK, "Rename successful"); + if (remote_fd < 0) + goto close_local_and_bail; + + bytes_transferred = bb_copyfd_eof(remote_fd, local_file_fd); + close(remote_fd); + if (bytes_transferred < 0) + WRITE_ERR(FTP_BADSENDFILE); else - cmdio_write(FTP_FILEFAIL, "Rename failed"); + WRITE_OK(FTP_TRANSFEROK); + + close_local_and_bail: + close(local_file_fd); + G.local_file_fd = 0; } -#endif /* ENABLE_FEATURE_FTP_WRITE */ static void -handle_nlst(void) +handle_stor(void) { - handle_dir_common(0, 0); + handle_upload_common(0, 0); } -#if ENABLE_FEATURE_FTP_WRITE static void handle_appe(void) { + G.restart_pos = 0; handle_upload_common(1, 0); } -#endif - -static void -handle_help(void) -{ - cmdio_write_hyphen(FTP_HELP, "Recognized commands:"); - cmdio_write_raw(" ALLO CDUP CWD HELP LIST\r\n" - " MODE NLST NOOP PASS PASV PORT PWD QUIT\r\n" - " REST RETR STAT STRU SYST TYPE USER\r\n" -#if ENABLE_FEATURE_FTP_WRITE - " APPE DELE MKD RMD RNFR RNTO STOR STOU\r\n" -#endif - ); - cmdio_write(FTP_HELP, "Help OK"); -} -#if ENABLE_FEATURE_FTP_WRITE static void handle_stou(void) { + G.restart_pos = 0; handle_upload_common(0, 1); } -#endif +#endif /* ENABLE_FEATURE_FTP_WRITE */ -static void -handle_stat(void) +static uint32_t +cmdio_get_cmd_and_arg(void) { - cmdio_write_hyphen(FTP_STATOK, "FTP server status:"); - cmdio_write_raw(" TYPE: BINARY\r\n"); - cmdio_write(FTP_STATOK, "End of status"); -} + int len; + uint32_t cmdval; + char *cmd; -static void -handle_stat_file(void) -{ - handle_dir_common(1, 1); -} + alarm(G.timeout); + + free(G.ftp_cmd); + { + /* Paranoia. Peer may send 1 gigabyte long cmd... */ + /* Using separate len_on_stk instead of len optimizes + * code size (allows len to be in CPU register) */ + size_t len_on_stk = 8 * 1024; + G.ftp_cmd = cmd = xmalloc_fgets_str_len(stdin, "\r\n", &len_on_stk); + if (!cmd) + exit(0); + len = len_on_stk; + } -/* TODO: libbb candidate (tftp has another copy) */ -static len_and_sockaddr *get_sock_lsa(int s) -{ - len_and_sockaddr *lsa; - socklen_t len = 0; - - if (getsockname(s, NULL, &len) != 0) - return NULL; - lsa = xzalloc(LSA_LEN_SIZE + len); - lsa->len = len; - getsockname(s, &lsa->u.sa, &lsa->len); - return lsa; + /* De-escape telnet: 0xff,0xff => 0xff */ + /* RFC959 says that ABOR, STAT, QUIT may be sent even during + * data transfer, and may be preceded by telnet's "Interrupt Process" + * code (two-byte sequence 255,244) and then by telnet "Synch" code + * 255,242 (byte 242 is sent with TCP URG bit using send(MSG_OOB) + * and may generate SIGURG on our side. See RFC854). + * So far we don't support that (may install SIGURG handler if we'd want to), + * but we need to at least remove 255,xxx pairs. lftp sends those. */ + /* Then de-escape FTP: NUL => '\n' */ + /* Testing for \xff: + * Create file named '\xff': echo Hello >`echo -ne "\xff"` + * Try to get it: ftpget -v 127.0.0.1 Eff `echo -ne "\xff\xff"` + * (need "\xff\xff" until ftpget applet is fixed to do escaping :) + * Testing for embedded LF: + * LF_HERE=`echo -ne "LF\nHERE"` + * echo Hello >"$LF_HERE" + * ftpget -v 127.0.0.1 LF_HERE "$LF_HERE" + */ + { + int dst, src; + + /* Strip "\r\n" if it is there */ + if (len != 0 && cmd[len - 1] == '\n') { + len--; + if (len != 0 && cmd[len - 1] == '\r') + len--; + cmd[len] = '\0'; + } + src = strchrnul(cmd, 0xff) - cmd; + /* 99,99% there are neither NULs nor 255s and src == len */ + if (src < len) { + dst = src; + do { + if ((unsigned char)(cmd[src]) == 255) { + src++; + /* 255,xxx - skip 255 */ + if ((unsigned char)(cmd[src]) != 255) { + /* 255,!255 - skip both */ + src++; + continue; + } + /* 255,255 - retain one 255 */ + } + /* NUL => '\n' */ + cmd[dst++] = cmd[src] ? cmd[src] : '\n'; + src++; + } while (src < len); + cmd[dst] = '\0'; + } + } + + if (G.verbose > 1) + verbose_log(cmd); + + G.ftp_arg = strchr(cmd, ' '); + if (G.ftp_arg != NULL) + *G.ftp_arg++ = '\0'; + + /* Uppercase and pack into uint32_t first word of the command */ + cmdval = 0; + while (*cmd) + cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20); + + return cmdval; } +#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) +enum { + const_ALLO = mk_const4('A', 'L', 'L', 'O'), + const_APPE = mk_const4('A', 'P', 'P', 'E'), + const_CDUP = mk_const4('C', 'D', 'U', 'P'), + const_CWD = mk_const3('C', 'W', 'D'), + const_DELE = mk_const4('D', 'E', 'L', 'E'), + const_EPSV = mk_const4('E', 'P', 'S', 'V'), + const_FEAT = mk_const4('F', 'E', 'A', 'T'), + const_HELP = mk_const4('H', 'E', 'L', 'P'), + const_LIST = mk_const4('L', 'I', 'S', 'T'), + const_MDTM = mk_const4('M', 'D', 'T', 'M'), + const_MKD = mk_const3('M', 'K', 'D'), + const_MODE = mk_const4('M', 'O', 'D', 'E'), + const_NLST = mk_const4('N', 'L', 'S', 'T'), + const_NOOP = mk_const4('N', 'O', 'O', 'P'), + const_PASS = mk_const4('P', 'A', 'S', 'S'), + const_PASV = mk_const4('P', 'A', 'S', 'V'), + const_PORT = mk_const4('P', 'O', 'R', 'T'), + const_PWD = mk_const3('P', 'W', 'D'), + const_QUIT = mk_const4('Q', 'U', 'I', 'T'), + const_REST = mk_const4('R', 'E', 'S', 'T'), + const_RETR = mk_const4('R', 'E', 'T', 'R'), + const_RMD = mk_const3('R', 'M', 'D'), + const_RNFR = mk_const4('R', 'N', 'F', 'R'), + const_RNTO = mk_const4('R', 'N', 'T', 'O'), + const_SIZE = mk_const4('S', 'I', 'Z', 'E'), + const_STAT = mk_const4('S', 'T', 'A', 'T'), + const_STOR = mk_const4('S', 'T', 'O', 'R'), + const_STOU = mk_const4('S', 'T', 'O', 'U'), + const_STRU = mk_const4('S', 'T', 'R', 'U'), + const_SYST = mk_const4('S', 'Y', 'S', 'T'), + 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), +#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 { - smallint user_was_specified = 0; + unsigned abs_timeout; + unsigned verbose_S; + smallint opts; INIT_G(); + abs_timeout = 1 * 60 * 60; + verbose_S = 0; + G.timeout = 2 * 60; + opt_complementary = "t+:T+:vv:SS"; +#if BB_MMU + opts = getopt32(argv, "vS" IF_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose, &verbose_S); +#else + opts = getopt32(argv, "l1vS" IF_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose, &verbose_S); + if (opts & (OPT_l|OPT_1)) { + /* Our secret backdoor to ls */ +/* TODO: pass -n? It prevents user/group resolution, which may not work in chroot anyway */ +/* TODO: pass -A? It shows dot files */ +/* TODO: pass --group-directories-first? would be nice, but ls doesn't do that yet */ + xchdir(argv[2]); + argv[2] = (char*)"--"; + /* memset(&G, 0, sizeof(G)); - ls_main does it */ + return ls_main(argc, argv); + } +#endif + if (G.verbose < verbose_S) + G.verbose = verbose_S; + if (abs_timeout | G.timeout) { + if (abs_timeout == 0) + abs_timeout = INT_MAX; + G.end_time = monotonic_sec() + abs_timeout; + if (G.timeout > abs_timeout) + G.timeout = abs_timeout; + } + strcpy(G.msg_ok + 4, MSG_OK ); + strcpy(G.msg_err + 4, MSG_ERR); + G.local_addr = get_sock_lsa(STDIN_FILENO); if (!G.local_addr) { /* This is confusing: @@ -984,88 +1163,174 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) * failure */ } - logmode = LOGMODE_SYSLOG; + if (!(opts & OPT_v)) + logmode = LOGMODE_NONE; + if (opts & OPT_S) { + /* LOG_NDELAY is needed since we may chroot later */ + openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON); + logmode |= LOGMODE_SYSLOG; + } + if (logmode) + applet_name = xasprintf("%s[%u]", applet_name, (int)getpid()); + +#if !BB_MMU + G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); + close_on_exec_on(G.root_fd); +#endif - USE_FEATURE_FTP_WRITE(G.write_enable =) getopt32(argv, "" USE_FEATURE_FTP_WRITE("w")); if (argv[optind]) { xchdir(argv[optind]); chroot("."); } -// if (G.local_addr->u.sa.sa_family != AF_INET) -// bb_error_msg_and_die("Only IPv4 is supported"); + //umask(077); - admin can set umask before starting us /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */ signal(SIGPIPE, SIG_IGN); - /* Set up options on the command socket */ + /* Set up options on the command socket (do we need these all? why?) */ setsockopt(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY, &const_int_1, sizeof(const_int_1)); setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); + /* Telnet protocol over command link may send "urgent" data, + * we prefer it to be received in the "normal" data stream: */ setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &const_int_1, sizeof(const_int_1)); - cmdio_write(FTP_GREET, "Welcome"); - - while (1) { - uint32_t cmdval = cmdio_get_cmd_and_arg(); - - if (cmdval == const_USER) { - if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0) - cmdio_write(FTP_LOGINERR, "Server is anonymous only"); - else { - user_was_specified = 1; - cmdio_write(FTP_GIVEPWORD, "Please specify the password"); + WRITE_OK(FTP_GREET); + signal(SIGALRM, timeout_handler); + +#ifdef IF_WE_WANT_TO_REQUIRE_LOGIN + { + smallint user_was_specified = 0; + while (1) { + uint32_t cmdval = cmdio_get_cmd_and_arg(); + + if (cmdval == const_USER) { + if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0) + cmdio_write_raw(STR(FTP_LOGINERR)" Server is anonymous only\r\n"); + else { + user_was_specified = 1; + cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify the password\r\n"); + } + } else if (cmdval == const_PASS) { + if (user_was_specified) + break; + cmdio_write_raw(STR(FTP_NEEDUSER)" Login with USER\r\n"); + } else if (cmdval == const_QUIT) { + WRITE_OK(FTP_GOODBYE); + return 0; + } else { + cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER and PASS\r\n"); } - } else if (cmdval == const_PASS) { - if (user_was_specified) - break; - cmdio_write(FTP_NEEDUSER, "Login with USER"); - } else if (cmdval == const_QUIT) { - cmdio_write(FTP_GOODBYE, "Goodbye"); - return 0; - } else { - cmdio_write(FTP_LOGINERR, - "Login with USER and PASS"); } } + WRITE_OK(FTP_LOGINOK); +#endif - umask(077); - cmdio_write(FTP_LOGINOK, "Login successful"); + /* RFC-959 Section 5.1 + * The following commands and options MUST be supported by every + * server-FTP and user-FTP, except in cases where the underlying + * file system or operating system does not allow or support + * a particular command. + * Type: ASCII Non-print, IMAGE, LOCAL 8 + * Mode: Stream + * Structure: File, Record* + * (Record structure is REQUIRED only for hosts whose file + * systems support record structure). + * Commands: + * USER, PASS, ACCT, [bbox: ACCT not supported] + * PORT, PASV, + * TYPE, MODE, STRU, + * RETR, STOR, APPE, + * RNFR, RNTO, DELE, + * CWD, CDUP, RMD, MKD, PWD, + * LIST, NLST, + * SYST, STAT, + * HELP, NOOP, QUIT. + */ + /* ACCOUNT (ACCT) + * "The argument field is a Telnet string identifying the user's account. + * The command is not necessarily related to the USER command, as some + * sites may require an account for login and others only for specific + * access, such as storing files. In the latter case the command may + * arrive at any time. + * There are reply codes to differentiate these cases for the automation: + * when account information is required for login, the response to + * a successful PASSword command is reply code 332. On the other hand, + * if account information is NOT required for login, the reply to + * a successful PASSword command is 230; and if the account information + * is needed for a command issued later in the dialogue, the server + * should return a 332 or 532 reply depending on whether it stores + * (pending receipt of the ACCounT command) or discards the command, + * respectively." + */ while (1) { uint32_t cmdval = cmdio_get_cmd_and_arg(); if (cmdval == const_QUIT) { - cmdio_write(FTP_GOODBYE, "Goodbye"); + WRITE_OK(FTP_GOODBYE); return 0; } - if (cmdval == const_PWD) + else if (cmdval == const_USER) + /* This would mean "ok, now give me PASS". */ + /*WRITE_OK(FTP_GIVEPWORD);*/ + /* vsftpd can be configured to not require that, + * and this also saves one roundtrip: + */ + WRITE_OK(FTP_LOGINOK); + else if (cmdval == const_PASS) + WRITE_OK(FTP_LOGINOK); + else if (cmdval == const_NOOP) + WRITE_OK(FTP_NOOPOK); + else if (cmdval == const_TYPE) + WRITE_OK(FTP_TYPEOK); + else if (cmdval == const_STRU) + WRITE_OK(FTP_STRUOK); + else if (cmdval == const_MODE) + WRITE_OK(FTP_MODEOK); + else if (cmdval == const_ALLO) + WRITE_OK(FTP_ALLOOK); + else if (cmdval == const_SYST) + cmdio_write_raw(STR(FTP_SYSTOK)" UNIX Type: L8\r\n"); + else if (cmdval == const_PWD) handle_pwd(); else if (cmdval == const_CWD) handle_cwd(); - else if (cmdval == const_CDUP) + else if (cmdval == const_CDUP) /* cd .. */ handle_cdup(); + /* HELP is nearly useless, but we can reuse FEAT for it */ + /* lftp uses FEAT */ + else if (cmdval == const_HELP || cmdval == const_FEAT) + handle_feat(cmdval == const_HELP + ? STRNUM32(FTP_HELP) + : STRNUM32(FTP_STATOK) + ); + else if (cmdval == const_LIST) /* ls -l */ + handle_list(); + else if (cmdval == const_NLST) /* "name list", bare ls */ + handle_nlst(); + /* SIZE is crucial for wget's download indicator etc */ + /* Mozilla, lftp use MDTM (presumably for caching) */ + else if (cmdval == const_SIZE || cmdval == const_MDTM) + handle_size_or_mdtm(cmdval == const_SIZE); + else if (cmdval == const_STAT) { + if (G.ftp_arg == NULL) + handle_stat(); + else + handle_stat_file(); + } else if (cmdval == const_PASV) handle_pasv(); + else if (cmdval == const_EPSV) + handle_epsv(); else if (cmdval == const_RETR) handle_retr(); - else if (cmdval == const_NOOP) - cmdio_write(FTP_NOOPOK, "NOOP ok"); - else if (cmdval == const_SYST) - cmdio_write(FTP_SYSTOK, "UNIX Type: L8"); - else if (cmdval == const_HELP) - handle_help(); - else if (cmdval == const_LIST) - handle_list(); - else if (cmdval == const_TYPE) - handle_type(); else if (cmdval == const_PORT) handle_port(); else if (cmdval == const_REST) handle_rest(); - else if (cmdval == const_NLST) - handle_nlst(); #if ENABLE_FEATURE_FTP_WRITE - else if (G.write_enable) { + else if (opts & OPT_w) { if (cmdval == const_STOR) handle_stor(); else if (cmdval == const_MKD) @@ -1074,45 +1339,19 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) handle_rmd(); else if (cmdval == const_DELE) handle_dele(); - else if (cmdval == const_RNFR) + else if (cmdval == const_RNFR) /* "rename from" */ handle_rnfr(); - else if (cmdval == const_RNTO) + else if (cmdval == const_RNTO) /* "rename to" */ handle_rnto(); else if (cmdval == const_APPE) handle_appe(); - else if (cmdval == const_STOU) + else if (cmdval == const_STOU) /* "store unique" */ handle_stou(); + else + goto bad_cmd; } #endif - else if (cmdval == const_STRU) { - if (G.ftp_arg - && (G.ftp_arg[0] | 0x20) == 'f' - && G.ftp_arg[1] == '\0' - ) { - cmdio_write(FTP_STRUOK, "Structure set to F"); - } else - cmdio_write(FTP_BADSTRU, "Bad STRU command"); - - } else if (cmdval == const_MODE) { - if (G.ftp_arg - && (G.ftp_arg[0] | 0x20) == 's' - && G.ftp_arg[1] == '\0' - ) { - cmdio_write(FTP_MODEOK, "Mode set to S"); - } else - cmdio_write(FTP_BADMODE, "Bad MODE command"); - } - else if (cmdval == const_ALLO) - cmdio_write(FTP_ALLOOK, "ALLO command ignored"); - else if (cmdval == const_STAT) { - if (G.ftp_arg == NULL) - handle_stat(); - else - handle_stat_file(); - } else if (cmdval == const_USER) - cmdio_write(FTP_LOGINERR, "Can't change to another user"); - else if (cmdval == const_PASS) - cmdio_write(FTP_LOGINOK, "Already logged in"); +#if 0 else if (cmdval == const_STOR || cmdval == const_MKD || cmdval == const_RMD @@ -1122,9 +1361,18 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) || cmdval == const_APPE || cmdval == const_STOU ) { - cmdio_write(FTP_NOPERM, "Permission denied"); - } else { - cmdio_write(FTP_BADCMD, "Unknown command"); + cmdio_write_raw(STR(FTP_NOPERM)" Permission denied\r\n"); + } +#endif + else { + /* Which unsupported commands were seen in the wild? + * (doesn't necessarily mean "we must support them") + * foo 1.2.3: XXXX - comment + */ +#if ENABLE_FEATURE_FTP_WRITE + bad_cmd: +#endif + cmdio_write_raw(STR(FTP_BADCMD)" Unknown command\r\n"); } } }