diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/ftpd.c | 377 |
1 files changed, 185 insertions, 192 deletions
diff --git a/networking/ftpd.c b/networking/ftpd.c index 6289edf..404bc98 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -9,6 +9,8 @@ * * Options: * -w - enable FTP write commands + * + * TODO: implement "421 Timeout" thingy (alarm(60) while waiting for a cmd). */ #include "libbb.h" @@ -98,7 +100,7 @@ struct globals { int data_fd; off_t restart_pos; char *ftp_cmp; - const char *ftp_arg; + char *ftp_arg; #if ENABLE_FEATURE_FTP_WRITE char *rnfr_filename; #endif @@ -156,22 +158,25 @@ replace_char(char *str, char from, char to) } static void -ftp_write_str_common(unsigned int status, const char *str, char sep) +ftp_write_str_common(unsigned status, const char *str, char sep) { char *escaped_str, *response; - size_t len; + int len; - escaped_str = replace_text(str, '\377', "\377\377"); + /* FTP allegedly uses telnet protocol for command link. + * In telnet, 0xff is an escape char, and needs to be escaped: */ + escaped_str = replace_text(str, '\xff', "\xff\xff"); - response = xasprintf("%u%c%s\r\n", status, sep, escaped_str); + response = xasprintf("%u%c%s\r", status, sep, escaped_str); free(escaped_str); + /* ?! does FTP send embedded LFs as NULs? wow */ len = strlen(response); replace_char(response, '\n', '\0'); - /* Change trailing '\0' back to '\n' */ - response[len - 1] = '\n'; + response[len++] = '\n'; /* tack on trailing '\n' */ xwrite(STDIN_FILENO, response, len); + free(response); } static void @@ -198,35 +203,68 @@ cmdio_write_raw(const char *p_text) xwrite_str(STDIN_FILENO, p_text); } -static uint32_t -cmdio_get_cmd_and_arg(void) +static void +handle_pwd(void) { - size_t len; - uint32_t cmdval; - char *cmd; + char *cwd, *promoted_cwd, *response; - free(G.ftp_cmp); - len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */ - G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len); - if (!cmd) - exit(0); + cwd = xrealloc_getcwd_or_warn(NULL); + if (cwd == NULL) + cwd = xstrdup(""); - len = strlen(cmd) - 1; - while (len >= 0 && cmd[len] == '\r') { - cmd[len] = '\0'; - len--; + /* 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); +} + +static void +handle_cwd(void) +{ + if (!G.ftp_arg || chdir(G.ftp_arg) != 0) { + cmdio_write(FTP_FILEFAIL, "Can't change directory"); + return; } + cmdio_write_ok(FTP_CWDOK); +} - G.ftp_arg = strchr(cmd, ' '); - if (G.ftp_arg != NULL) { - *(char *)G.ftp_arg = '\0'; - G.ftp_arg++; +static void +handle_cdup(void) +{ + G.ftp_arg = (char*)".."; + handle_cwd(); +} + +static void +handle_type(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_ok(FTP_TYPEOK); + } else { + cmdio_write(FTP_BADCMD, "Unrecognised TYPE command"); } - cmdval = 0; - while (*cmd) - cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20); +} - return cmdval; +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"); } static void @@ -265,7 +303,7 @@ ftpdataio_get_port_fd(void) { int remote_fd; - /* Do we want die or print error to client? */ + /* Do we want to die or print error to client? */ remote_fd = xconnect_stream(G.port_addr); init_data_sock_params(remote_fd); @@ -289,16 +327,16 @@ ftpdataio_dispose_transfer_fd(void) G.data_fd = -1; } -static int +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 int @@ -318,41 +356,6 @@ get_remote_transfer_fd(const char *p_status_msg) return remote_fd; } -static void -handle_pwd(void) -{ - char *cwd, *promoted_cwd, *response; - - cwd = xrealloc_getcwd_or_warn(NULL); - if (cwd == NULL) - cwd = xstrdup(""); - - /* 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); -} - -static void -handle_cwd(void) -{ - if (!G.ftp_arg || chdir(G.ftp_arg) != 0) { - cmdio_write(FTP_FILEFAIL, "Can't change directory"); - return; - } - cmdio_write_ok(FTP_CWDOK); -} - -static void -handle_cdup(void) -{ - G.ftp_arg = ".."; - handle_cwd(); -} - static int data_transfer_checks_ok(void) { @@ -365,15 +368,10 @@ data_transfer_checks_ok(void) } static void -port_cleanup(void) +port_pasv_cleanup(void) { free(G.port_addr); G.port_addr = NULL; -} - -static void -pasv_cleanup(void) -{ if (G.pasv_listen_fd > STDOUT_FILENO) close(G.pasv_listen_fd); G.pasv_listen_fd = -1; @@ -385,10 +383,10 @@ handle_pasv(void) int bind_retries = 10; unsigned short port; enum { min_port = 1024, max_port = 65535 }; - char *addr, *wire_addr, *response; + char *addr, *response; + + port_pasv_cleanup(); - 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); @@ -413,14 +411,13 @@ handle_pasv(void) bb_error_msg_and_die("can't create pasv socket"); addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa); - wire_addr = replace_text(addr, '.', ","); - free(addr); + replace_char(addr, '.', ','); response = xasprintf("Entering Passive Mode (%s,%u,%u)", - wire_addr, (int)(port >> 8), (int)(port & 255)); + addr, (int)(port >> 8), (int)(port & 255)); + free(addr); cmdio_write(FTP_PASVOK, response); - free(wire_addr); free(response); } @@ -428,37 +425,35 @@ static void handle_port(void) { unsigned short port; - char *raw = NULL, *port_part; + char *raw, *port_part; len_and_sockaddr *lsa = NULL; - pasv_cleanup(); - port_cleanup(); + port_pasv_cleanup(); - if (G.ftp_arg == NULL) - goto bail; + raw = G.ftp_arg; - raw = replace_text(G.ftp_arg, ',', "."); + /* buglets: + * xatou16 will accept wrong input, + * xatou16 will exit instead of generating error to peer + */ - port_part = strrchr(raw, '.'); + port_part = strrchr(raw, ','); if (port_part == NULL) goto bail; - port = xatou16(&port_part[1]); *port_part = '\0'; - port_part = strrchr(raw, '.'); + port_part = strrchr(raw, ','); if (port_part == NULL) goto bail; - port |= xatou16(&port_part[1]) << 8; *port_part = '\0'; + replace_char(raw, ',', '.'); lsa = xdotted2sockaddr(raw, port); -bail: - free(raw); - if (lsa == NULL) { + bail: cmdio_write(FTP_BADCMD, "Illegal PORT command"); return; } @@ -528,10 +523,10 @@ handle_retr(void) else cmdio_write_ok(FTP_TRANSFEROK); -port_pasv_cleanup_out: - port_cleanup(); - pasv_cleanup(); -file_close_out: + port_pasv_cleanup_out: + port_pasv_cleanup(); + + file_close_out: close(opened_file); } @@ -691,12 +686,11 @@ handle_dir_common(int full_details, int stat_cmd) } else write_dirstats(fd, ".", full_details); -bail: + bail: /* Well, if we can't open directory/file it doesn't matter */ if (!stat_cmd) { ftpdataio_dispose_transfer_fd(); - pasv_cleanup(); - port_cleanup(); + port_pasv_cleanup(); cmdio_write_ok(FTP_TRANSFEROK); } else cmdio_write_ok(FTP_STATFILE_OK); @@ -728,98 +722,8 @@ handle_stat(void) cmdio_write_ok(FTP_STATOK); } -static void -handle_type(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_ok(FTP_TYPEOK); - } else { - cmdio_write(FTP_BADCMD, "Unrecognised TYPE command"); - } -} - -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_upload_common(int is_append, int is_unique) -{ - char *tempname = NULL; - int trans_ret; - int new_file_fd; - int remote_fd; - off_t offset = G.restart_pos; - - G.restart_pos = 0; - if (!G.ftp_arg || !data_transfer_checks_ok()) - return; - - if (is_unique) { - tempname = xstrdup("FILE: uniq.XXXXXX"); - /* - * XXX Use mkostemp here? vsftpd opens file with O_CREAT, O_WRONLY, - * O_APPEND and O_EXCL flags... - */ - new_file_fd = mkstemp(tempname + 6); - } 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"); - 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 (tempname) { - remote_fd = get_remote_transfer_fd(tempname); - free(tempname); - } 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_ok(FTP_TRANSFEROK); - -bail: - port_cleanup(); - pasv_cleanup(); - close(new_file_fd); -} - -static void handle_mkd(void) { if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) { @@ -892,6 +796,62 @@ handle_rnto(void) } static void +handle_upload_common(int is_append, int is_unique) +{ + char *tempname = NULL; + int trans_ret; + int local_file_fd; + int remote_fd; + off_t offset; + + offset = G.restart_pos; + G.restart_pos = 0; + + if (!data_transfer_checks_ok()) + return; + + local_file_fd = -1; + if (is_unique) { + tempname = xstrdup("FILE: uniq.XXXXXX"); + local_file_fd = mkstemp(tempname + 6); + } 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) { + cmdio_write(FTP_UPLOADFAIL, "Can't create file"); + return; + } + + /* TODO: paranoia: fstat it, refuse to do anything if it's not a regular file */ + + if (offset) + xlseek(local_file_fd, offset, SEEK_SET); + + remote_fd = get_remote_transfer_fd(tempname ? tempname : "Ok to send data"); + free(tempname); + + if (remote_fd < 0) + goto bail; + + trans_ret = bb_copyfd_eof(remote_fd, local_file_fd); + ftpdataio_dispose_transfer_fd(); + + if (trans_ret < 0) + cmdio_write(FTP_BADSENDFILE, "Failure writing to local file"); + else + cmdio_write_ok(FTP_TRANSFEROK); + + bail: + port_pasv_cleanup(); + close(local_file_fd); +} + +static void handle_stor(void) { handle_upload_common(0, 0); @@ -900,16 +860,49 @@ handle_stor(void) static void handle_appe(void) { + G.restart_pos = 0; handle_upload_common(1, 0); } static void handle_stou(void) { + G.restart_pos = 0; handle_upload_common(0, 1); } #endif /* ENABLE_FEATURE_FTP_WRITE */ +static uint32_t +cmdio_get_cmd_and_arg(void) +{ + size_t len; + uint32_t cmdval; + char *cmd; + + free(G.ftp_cmp); + len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */ + G.ftp_cmp = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len); + if (!cmd) + exit(0); + + len = strlen(cmd) - 1; + while (len >= 0 && cmd[len] == '\r') { + cmd[len] = '\0'; + len--; + } + + 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); + + return cmdval; +} + int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int ftpd_main(int argc UNUSED_PARAM, char **argv) { |