X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Ftftp.c;h=5ebd221059f8b4782ba3b922d8ade21f2f4ca089;hb=253c4e787a799a3e1f92957ed791b5222f8d2f64;hp=bfe94aca2a14734d982cc110108c621123aa09e5;hpb=000b9ba91f64a348d697fb22a546cfb4db1d9f0e;p=oweals%2Fbusybox.git diff --git a/networking/tftp.c b/networking/tftp.c index bfe94aca2..5ebd22105 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -1,8 +1,6 @@ /* vi: set sw=4 ts=4: */ -/* ------------------------------------------------------------------------- - * tftp.c - * - * A simple tftp client for busybox. +/* + * A simple tftp client/server for busybox. * Tries to follow RFC1350. * Only "octet" mode supported. * Optional blocksize negotiation (RFC2347 + RFC2348) @@ -16,21 +14,121 @@ * * utftp: Copyright (C) 1999 Uwe Ohse * - * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. - * ------------------------------------------------------------------------- */ - -#include "busybox.h" - - -#define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ -#define TFTP_TIMEOUT 5 /* seconds */ -#define TFTP_NUM_RETRIES 5 /* number of retries */ - -static const char * const MODE_OCTET = "octet"; -#define MODE_OCTET_LEN 6 /* sizeof(MODE_OCTET)*/ - -static const char * const OPTION_BLOCKSIZE = "blksize"; -#define OPTION_BLOCKSIZE_LEN 8 /* sizeof(OPTION_BLOCKSIZE) */ + * tftpd added by Denys Vlasenko & Vladimir Dronnikov + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + */ +//config:config TFTP +//config: bool "tftp (11 kb)" +//config: default y +//config: help +//config: Trivial File Transfer Protocol client. TFTP is usually used +//config: for simple, small transfers such as a root image +//config: for a network-enabled bootloader. +//config: +//config:config FEATURE_TFTP_PROGRESS_BAR +//config: bool "Enable progress bar" +//config: default y +//config: depends on TFTP +//config: +//config:config TFTPD +//config: bool "tftpd (10 kb)" +//config: default y +//config: help +//config: Trivial File Transfer Protocol server. +//config: It expects that stdin is a datagram socket and a packet +//config: is already pending on it. It will exit after one transfer. +//config: In other words: it should be run from inetd in nowait mode, +//config: or from udpsvd. Example: "udpsvd -E 0 69 tftpd DIR" +//config: +//config:config FEATURE_TFTP_GET +//config: bool "Enable 'tftp get' and/or tftpd upload code" +//config: default y +//config: depends on TFTP || TFTPD +//config: help +//config: Add support for the GET command within the TFTP client. This allows +//config: a client to retrieve a file from a TFTP server. +//config: Also enable upload support in tftpd, if tftpd is selected. +//config: +//config: Note: this option does _not_ make tftpd capable of download +//config: (the usual operation people need from it)! +//config: +//config:config FEATURE_TFTP_PUT +//config: bool "Enable 'tftp put' and/or tftpd download code" +//config: default y +//config: depends on TFTP || TFTPD +//config: help +//config: Add support for the PUT command within the TFTP client. This allows +//config: a client to transfer a file to a TFTP server. +//config: Also enable download support in tftpd, if tftpd is selected. +//config: +//config:config FEATURE_TFTP_BLOCKSIZE +//config: bool "Enable 'blksize' and 'tsize' protocol options" +//config: default y +//config: depends on TFTP || TFTPD +//config: help +//config: Allow tftp to specify block size, and tftpd to understand +//config: "blksize" and "tsize" options. +//config: +//config:config TFTP_DEBUG +//config: bool "Enable debug" +//config: default n +//config: depends on TFTP || TFTPD +//config: help +//config: Make tftp[d] print debugging messages on stderr. +//config: This is useful if you are diagnosing a bug in tftp[d]. + +//applet:#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT +//applet:IF_TFTP(APPLET(tftp, BB_DIR_USR_BIN, BB_SUID_DROP)) +//applet:IF_TFTPD(APPLET(tftpd, BB_DIR_USR_SBIN, BB_SUID_DROP)) +//applet:#endif + +//kbuild:lib-$(CONFIG_TFTP) += tftp.o +//kbuild:lib-$(CONFIG_TFTPD) += tftp.o + +//usage:#define tftp_trivial_usage +//usage: "[OPTIONS] HOST [PORT]" +//usage:#define tftp_full_usage "\n\n" +//usage: "Transfer a file from/to tftp server\n" +//usage: "\n -l FILE Local FILE" +//usage: "\n -r FILE Remote FILE" +//usage: IF_FEATURE_TFTP_GET( +//usage: "\n -g Get file" +//usage: ) +//usage: IF_FEATURE_TFTP_PUT( +//usage: "\n -p Put file" +//usage: ) +//usage: IF_FEATURE_TFTP_BLOCKSIZE( +//usage: "\n -b SIZE Transfer blocks of SIZE octets" +//usage: ) +//usage: +//usage:#define tftpd_trivial_usage +//usage: "[-cr] [-u USER] [DIR]" +//usage:#define tftpd_full_usage "\n\n" +//usage: "Transfer a file on tftp client's request\n" +//usage: "\n" +//usage: "tftpd should be used as an inetd service.\n" +//usage: "tftpd's line for inetd.conf:\n" +//usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n" +//usage: "It also can be ran from udpsvd:\n" +//usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n" +//usage: "\n -r Prohibit upload" +//usage: "\n -c Allow file creation via upload" +//usage: "\n -u Access files as USER" +//usage: "\n -l Log to syslog (inetd mode requires this)" + +#include "libbb.h" +#include "common_bufsiz.h" +#include + +#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT + +#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ +#define TFTP_BLKSIZE_DEFAULT_STR "512" +/* Was 50 ms but users asked to bump it up a bit */ +#define TFTP_TIMEOUT_MS 100 +#define TFTP_MAXTIMEOUT_MS 2000 +#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */ /* opcodes we support */ #define TFTP_RRQ 1 @@ -40,80 +138,147 @@ static const char * const OPTION_BLOCKSIZE = "blksize"; #define TFTP_ERROR 5 #define TFTP_OACK 6 -static const char *const tftp_bb_error_msg[] = { - "Undefined error", - "File not found", - "Access violation", - "Disk full or allocation error", - "Illegal TFTP operation", - "Unknown transfer ID", - "File already exists", - "No such user" +/* error codes sent over network (we use only 0, 1, 3 and 8) */ +/* generic (error message is included in the packet) */ +#define ERR_UNSPEC 0 +#define ERR_NOFILE 1 +#define ERR_ACCESS 2 +/* disk full or allocation exceeded */ +#define ERR_WRITE 3 +#define ERR_OP 4 +#define ERR_BAD_ID 5 +#define ERR_EXIST 6 +#define ERR_BAD_USER 7 +#define ERR_BAD_OPT 8 + +/* masks coming from getopt32 */ +enum { + TFTP_OPT_GET = (1 << 0), + TFTP_OPT_PUT = (1 << 1), + /* pseudo option: if set, it's tftpd */ + TFTPD_OPT = (1 << 7) * ENABLE_TFTPD, + TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD, + TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD, + TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD, + TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD, }; -#define tftp_cmd_get ENABLE_FEATURE_TFTP_GET - -#if ENABLE_FEATURE_TFTP_PUT -# define tftp_cmd_put (tftp_cmd_get+ENABLE_FEATURE_TFTP_PUT) +#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT +#define IF_GETPUT(...) +#define CMD_GET(cmd) 1 +#define CMD_PUT(cmd) 0 +#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT +#define IF_GETPUT(...) +#define CMD_GET(cmd) 0 +#define CMD_PUT(cmd) 1 #else -# define tftp_cmd_put 0 +#define IF_GETPUT(...) __VA_ARGS__ +#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET) +#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT) +#endif +/* NB: in the code below + * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive + */ + + +struct globals { + /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */ + uint8_t error_pkt[4 + 32]; + struct passwd *pw; + /* Used in tftpd_main() for initial packet */ + /* Some HP PA-RISC firmware always sends fixed 516-byte requests */ + char block_buf[516]; + char block_buf_tail[1]; +#if ENABLE_FEATURE_TFTP_PROGRESS_BAR + off_t pos; + off_t size; + const char *file; + bb_progress_t pmt; +#endif +} FIX_ALIASING; +#define G (*(struct globals*)bb_common_bufsiz1) +#define INIT_G() do { \ + setup_common_bufsiz(); \ + BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \ +} while (0) + +#define G_error_pkt_reason (G.error_pkt[3]) +#define G_error_pkt_str ((char*)(G.error_pkt + 4)) + +#if ENABLE_FEATURE_TFTP_PROGRESS_BAR && ENABLE_FEATURE_TFTP_BLOCKSIZE +static void tftp_progress_update(void) +{ + bb_progress_update(&G.pmt, 0, G.pos, G.size); +} +static void tftp_progress_init(void) +{ + bb_progress_init(&G.pmt, G.file); + tftp_progress_update(); +} +static void tftp_progress_done(void) +{ + if (is_bb_progress_inited(&G.pmt)) { + tftp_progress_update(); + bb_putchar_stderr('\n'); + bb_progress_free(&G.pmt); + } +} +#else +# define tftp_progress_update() ((void)0) +# define tftp_progress_init() ((void)0) +# define tftp_progress_done() ((void)0) #endif +#if ENABLE_FEATURE_TFTP_BLOCKSIZE -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - -static int tftp_blocksize_check(int blocksize, int bufsize) +static int tftp_blksize_check(const char *blksize_str, int maxsize) { - /* Check if the blocksize is valid: + /* Check if the blksize is valid: * RFC2348 says between 8 and 65464, * but our implementation makes it impossible - * to use blocksizes smaller than 22 octets. - */ - - if ((bufsize && (blocksize > bufsize)) || - (blocksize < 8) || (blocksize > 65564)) { - bb_error_msg("bad blocksize"); - return 0; + * to use blksizes smaller than 22 octets. */ + unsigned blksize = bb_strtou(blksize_str, NULL, 10); + if (errno + || (blksize < 24) || (blksize > maxsize) + ) { + bb_error_msg("bad blocksize '%s'", blksize_str); + return -1; } - - return blocksize; +# if ENABLE_TFTP_DEBUG + bb_info_msg("using blksize %u", blksize); +# endif + return blksize; } -static char *tftp_option_get(char *buf, int len, const char * const option) +static char *tftp_get_option(const char *option, char *buf, int len) { int opt_val = 0; int opt_found = 0; int k; - while (len > 0) { - - /* Make sure the options are terminated correctly */ + /* buf points to: + * "opt_nameopt_valopt_name2opt_val2..." */ + while (len > 0) { + /* Make sure options are terminated correctly */ for (k = 0; k < len; k++) { if (buf[k] == '\0') { - break; + goto nul_found; } } - - if (k >= len) { - break; - } - - if (opt_val == 0) { + return NULL; + nul_found: + if (opt_val == 0) { /* it's "name" part */ if (strcasecmp(buf, option) == 0) { opt_found = 1; } - } else { - if (opt_found) { - return buf; - } + } else if (opt_found) { + return buf; } k++; - buf += k; len -= k; - opt_val ^= 1; } @@ -122,440 +287,674 @@ static char *tftp_option_get(char *buf, int len, const char * const option) #endif -static int tftp(const int cmd, const struct hostent *host, - const char *remotefile, const int localfd, - const unsigned short port, int tftp_bufsize) +static int tftp_protocol( + /* NULL if tftp, !NULL if tftpd: */ + len_and_sockaddr *our_lsa, + len_and_sockaddr *peer_lsa, + const char *local_file + IF_TFTP(, const char *remote_file) +#if !ENABLE_TFTP +# define remote_file NULL +#endif + /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */ + IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size) + IF_FEATURE_TFTP_BLOCKSIZE(, int blksize)) { - struct sockaddr_in sa; - struct sockaddr_in from; - struct timeval tv; - socklen_t fromlen; - fd_set rfds; - int socketfd; +#if !ENABLE_FEATURE_TFTP_BLOCKSIZE + enum { blksize = TFTP_BLKSIZE_DEFAULT }; +#endif + + struct pollfd pfd[1]; +#define socket_fd (pfd[0].fd) int len; - int opcode = 0; - int finished = 0; - int timeout = TFTP_NUM_RETRIES; - unsigned short block_nr = 1; - unsigned short tmp; + int send_len; + IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;) + smallint finished = 0; + uint16_t opcode; + uint16_t block_nr; + uint16_t recv_blk; + int open_mode, local_fd; + int retries, waittime_ms; + int io_bufsize = blksize + 4; char *cp; - - USE_FEATURE_TFTP_BLOCKSIZE(int want_option_ack = 0;) - /* Can't use RESERVE_CONFIG_BUFFER here since the allocation - * size varies meaning BUFFERS_GO_ON_STACK would fail */ - char *buf=xmalloc(tftp_bufsize += 4); - - if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { - /* need to unlink the localfile, so don't use xsocket here. */ - bb_perror_msg("socket"); - return EXIT_FAILURE; + * size varies meaning BUFFERS_GO_ON_STACK would fail. + * + * We must keep the transmit and receive buffers separate + * in case we rcv a garbage pkt - we need to rexmit the last pkt. + */ + char *xbuf = xmalloc(io_bufsize); + char *rbuf = xmalloc(io_bufsize); + + socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); + setsockopt_reuseaddr(socket_fd); + + if (!ENABLE_TFTP || our_lsa) { /* tftpd */ + /* Create a socket which is: + * 1. bound to IP:port peer sent 1st datagram to, + * 2. connected to peer's IP:port + * This way we will answer from the IP:port peer + * expects, will not get any other packets on + * the socket, and also plain read/write will work. */ + xbind(socket_fd, &our_lsa->u.sa, our_lsa->len); + xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); + + /* Is there an error already? Send pkt and bail out */ + if (G_error_pkt_reason || G_error_pkt_str[0]) + goto send_err_pkt; + + if (G.pw) { + change_identity(G.pw); /* initgroups, setgid, setuid */ + } } - len = sizeof(sa); - - memset(&sa, 0, len); - xbind(socketfd, (struct sockaddr *)&sa, len); - - sa.sin_family = host->h_addrtype; - sa.sin_port = port; - memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr, - sizeof(sa.sin_addr)); - - /* build opcode */ - if (cmd & tftp_cmd_get) { - opcode = TFTP_RRQ; + /* Prepare open mode */ + if (CMD_PUT(option_mask32)) { + open_mode = O_RDONLY; + } else { + open_mode = O_WRONLY | O_TRUNC | O_CREAT; +#if ENABLE_TFTPD + if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { + /* tftpd without -c */ + open_mode = O_WRONLY | O_TRUNC; + } +#endif } - if (cmd & tftp_cmd_put) { + + /* Examples of network traffic. + * Note two cases when ACKs with block# of 0 are sent. + * + * Download without options: + * tftp -> "\0\1FILENAME\0octet\0" + * "\0\3\0\1FILEDATA..." <- tftpd + * tftp -> "\0\4\0\1" + * ... + * Download with option of blksize 16384: + * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0" + * "\0\6blksize\00016384\0" <- tftpd + * tftp -> "\0\4\0\0" + * "\0\3\0\1FILEDATA..." <- tftpd + * tftp -> "\0\4\0\1" + * ... + * Upload without options: + * tftp -> "\0\2FILENAME\0octet\0" + * "\0\4\0\0" <- tftpd + * tftp -> "\0\3\0\1FILEDATA..." + * "\0\4\0\1" <- tftpd + * ... + * Upload with option of blksize 16384: + * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0" + * "\0\6blksize\00016384\0" <- tftpd + * tftp -> "\0\3\0\1FILEDATA..." + * "\0\4\0\1" <- tftpd + * ... + */ + block_nr = 1; + cp = xbuf + 2; + + if (!ENABLE_TFTP || our_lsa) { /* tftpd */ + /* Open file (must be after changing user) */ + local_fd = open(local_file, open_mode, 0666); + if (local_fd < 0) { + G_error_pkt_reason = ERR_NOFILE; + strcpy(G_error_pkt_str, "can't open file"); + goto send_err_pkt; + } +/* gcc 4.3.1 would NOT optimize it out as it should! */ +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) { + /* Create and send OACK packet. */ + /* For the download case, block_nr is still 1 - + * we expect 1st ACK from peer to be for (block_nr-1), + * that is, for "block 0" which is our OACK pkt */ + opcode = TFTP_OACK; + goto add_blksize_opt; + } +#endif + if (CMD_GET(option_mask32)) { + /* It's upload and we don't send OACK. + * We must ACK 1st packet (with filename) + * as if it is "block 0" */ + block_nr = 0; + } + } else { /* tftp */ + /* Open file (must be after changing user) */ + local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO; + if (NOT_LONE_DASH(local_file)) + local_fd = xopen(local_file, open_mode); +/* Removing #if, or using if() statement instead of #if may lead to + * "warning: null argument where non-null required": */ +#if ENABLE_TFTP + /* tftp */ + + /* We can't (and don't really need to) bind the socket: + * we don't know from which local IP datagrams will be sent, + * but kernel will pick the same IP every time (unless routing + * table is changed), thus peer will see dgrams consistently + * coming from the same IP. + * We would like to connect the socket, but since peer's + * UDP code can be less perfect than ours, _peer's_ IP:port + * in replies may differ from IP:port we used to send + * our first packet. We can connect() only when we get + * first reply. */ + + /* build opcode */ opcode = TFTP_WRQ; + if (CMD_GET(option_mask32)) { + opcode = TFTP_RRQ; + } + /* add filename and mode */ + /* fill in packet if the filename fits into xbuf */ + len = strlen(remote_file) + 1; + if (2 + len + sizeof("octet") >= io_bufsize) { + bb_error_msg("remote filename is too long"); + goto ret; + } + strcpy(cp, remote_file); + cp += len; + /* add "mode" part of the packet */ + strcpy(cp, "octet"); + cp += sizeof("octet"); + +# if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size) + goto send_pkt; + + /* Need to add option to pkt */ + if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) { + bb_error_msg("remote filename is too long"); + goto ret; + } + expect_OACK = 1; +# endif +#endif /* ENABLE_TFTP */ + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + add_blksize_opt: + if (blksize != TFTP_BLKSIZE_DEFAULT) { + /* add "blksize", , blksize, */ + strcpy(cp, "blksize"); + cp += sizeof("blksize"); + cp += snprintf(cp, 6, "%d", blksize) + 1; + } + if (want_transfer_size) { + /* add "tsize", , size, (see RFC2349) */ + /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC) + * and this makes server to send "tsize" option with the size */ + /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */ + /* if tftpd and downloading, we are answering to client's request */ + /* if tftpd and uploading: !want_transfer_size, this code is not executed */ + struct stat st; + strcpy(cp, "tsize"); + cp += sizeof("tsize"); + st.st_size = 0; + fstat(local_fd, &st); + cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1; +# if ENABLE_FEATURE_TFTP_PROGRESS_BAR + /* Save for progress bar. If 0 (tftp downloading), + * we look at server's reply later */ + G.size = st.st_size; + if (remote_file && st.st_size) + tftp_progress_init(); +# endif + } +#endif + /* First packet is built, so skip packet generation */ + goto send_pkt; } + /* Using mostly goto's - continue/break will be less clear + * in where we actually jump to */ while (1) { - - cp = buf; - - /* first create the opcode part */ - *((unsigned short *) cp) = htons(opcode); + /* Build ACK or DATA */ + cp = xbuf + 2; + *((uint16_t*)cp) = htons(block_nr); cp += 2; - - /* add filename and mode */ - if (((cmd & tftp_cmd_get) && (opcode == TFTP_RRQ)) || - ((cmd & tftp_cmd_put) && (opcode == TFTP_WRQ))) - { - int too_long = 0; - - /* see if the filename fits into buf - * and fill in packet. */ - len = strlen(remotefile) + 1; - - if ((cp + len) >= &buf[tftp_bufsize - 1]) { - too_long = 1; - } else { - safe_strncpy(cp, remotefile, len); - cp += len; - } - - if (too_long || ((&buf[tftp_bufsize - 1] - cp) < MODE_OCTET_LEN)) { - bb_error_msg("remote filename too long"); - break; - } - - /* add "mode" part of the package */ - memcpy(cp, MODE_OCTET, MODE_OCTET_LEN); - cp += MODE_OCTET_LEN; - -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - - len = tftp_bufsize - 4; /* data block size */ - - if (len != TFTP_BLOCKSIZE_DEFAULT) { - - if ((&buf[tftp_bufsize - 1] - cp) < 15) { - bb_error_msg("remote filename too long"); - break; - } - - /* add "blksize" + number of blocks */ - memcpy(cp, OPTION_BLOCKSIZE, OPTION_BLOCKSIZE_LEN); - cp += OPTION_BLOCKSIZE_LEN; - cp += snprintf(cp, 6, "%d", len) + 1; - - want_option_ack = 1; + block_nr++; + opcode = TFTP_ACK; + if (CMD_PUT(option_mask32)) { + opcode = TFTP_DATA; + len = full_read(local_fd, cp, blksize); + if (len < 0) { + goto send_read_err_pkt; } -#endif - } - - /* add ack and data */ - - if (((cmd & tftp_cmd_get) && (opcode == TFTP_ACK)) || - ((cmd & tftp_cmd_put) && (opcode == TFTP_DATA))) { - - *((unsigned short *) cp) = htons(block_nr); - - cp += 2; - - block_nr++; - - if ((cmd & tftp_cmd_put) && (opcode == TFTP_DATA)) { - len = full_read(localfd, cp, tftp_bufsize - 4); - - if (len < 0) { - bb_perror_msg(bb_msg_read_error); - break; - } - - if (len != (tftp_bufsize - 4)) { - finished++; - } - - cp += len; + if (len != blksize) { + finished = 1; } + cp += len; + IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;) } + send_pkt: + /* Send packet */ + *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */ + send_len = cp - xbuf; + /* NB: send_len value is preserved in code below + * for potential resend */ + + retries = TFTP_NUM_RETRIES; /* re-initialize */ + waittime_ms = TFTP_TIMEOUT_MS; + + send_again: +#if ENABLE_TFTP_DEBUG + fprintf(stderr, "sending %u bytes\n", send_len); + for (cp = xbuf; cp < &xbuf[send_len]; cp++) + fprintf(stderr, "%02x ", (unsigned char) *cp); + fprintf(stderr, "\n"); +#endif + xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); - - /* send packet */ - - - timeout = TFTP_NUM_RETRIES; /* re-initialize */ - do { - - len = cp - buf; - -#ifdef CONFIG_DEBUG_TFTP - fprintf(stderr, "sending %u bytes\n", len); - for (cp = buf; cp < &buf[len]; cp++) - fprintf(stderr, "%02x ", (unsigned char) *cp); - fprintf(stderr, "\n"); +#if ENABLE_FEATURE_TFTP_PROGRESS_BAR + if (is_bb_progress_inited(&G.pmt)) + tftp_progress_update(); #endif - if (sendto(socketfd, buf, len, 0, - (struct sockaddr *) &sa, sizeof(sa)) < 0) { - bb_perror_msg("send"); - len = -1; - break; + /* Was it final ACK? then exit */ + if (finished && (opcode == TFTP_ACK)) + goto ret; + + recv_again: + /* Receive packet */ + /*pfd[0].fd = socket_fd;*/ + pfd[0].events = POLLIN; + switch (safe_poll(pfd, 1, waittime_ms)) { + default: + /*bb_perror_msg("poll"); - done in safe_poll */ + goto ret; + case 0: + retries--; + if (retries == 0) { + tftp_progress_done(); + bb_error_msg("timeout"); + goto ret; /* no err packet sent */ } - - if (finished && (opcode == TFTP_ACK)) { - break; + /* exponential backoff with limit */ + waittime_ms += waittime_ms/2; + if (waittime_ms > TFTP_MAXTIMEOUT_MS) { + waittime_ms = TFTP_MAXTIMEOUT_MS; } - /* receive packet */ - - memset(&from, 0, sizeof(from)); - fromlen = sizeof(from); - - tv.tv_sec = TFTP_TIMEOUT; - tv.tv_usec = 0; - - FD_ZERO(&rfds); - FD_SET(socketfd, &rfds); - - switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) { - case 1: - len = recvfrom(socketfd, buf, tftp_bufsize, 0, - (struct sockaddr *) &from, &fromlen); - - if (len < 0) { - bb_perror_msg("recvfrom"); - break; - } - - timeout = 0; - - if (sa.sin_port == port) { - sa.sin_port = from.sin_port; - } - if (sa.sin_port == from.sin_port) { - break; - } - - /* fall-through for bad packets! */ - /* discard the packet - treat as timeout */ - timeout = TFTP_NUM_RETRIES; - case 0: - bb_error_msg("timeout"); - - timeout--; - if (timeout == 0) { - len = -1; - bb_error_msg("last timeout"); - } - break; - default: - bb_perror_msg("select"); - len = -1; + goto send_again; /* resend last sent pkt */ + case 1: + if (!our_lsa) { + /* tftp (not tftpd!) receiving 1st packet */ + our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */ + len = recvfrom(socket_fd, rbuf, io_bufsize, 0, + &peer_lsa->u.sa, &peer_lsa->len); + /* Our first dgram went to port 69 + * but reply may come from different one. + * Remember and use this new port (and IP) */ + if (len >= 0) + xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); + } else { + /* tftpd, or not the very first packet: + * socket is connect()ed, can just read from it. */ + /* Don't full_read()! + * This is not TCP, one read == one pkt! */ + len = safe_read(socket_fd, rbuf, io_bufsize); + } + if (len < 0) { + goto send_read_err_pkt; + } + if (len < 4) { /* too small? */ + goto recv_again; } - - } while (timeout && (len >= 0)); - - if ((finished) || (len < 0)) { - break; } - /* process received packet */ - - opcode = ntohs(*((unsigned short *) buf)); - tmp = ntohs(*((unsigned short *) &buf[2])); - -#ifdef CONFIG_DEBUG_TFTP - fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp); + /* Process recv'ed packet */ + opcode = ntohs( ((uint16_t*)rbuf)[0] ); + recv_blk = ntohs( ((uint16_t*)rbuf)[1] ); +#if ENABLE_TFTP_DEBUG + fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk); #endif - if (opcode == TFTP_ERROR) { - const char *msg = NULL; - - if (buf[4] != '\0') { - msg = &buf[4]; - buf[tftp_bufsize - 1] = '\0'; - } else if (tmp < (sizeof(tftp_bb_error_msg) - / sizeof(char *))) { - - msg = tftp_bb_error_msg[tmp]; + static const char errcode_str[] ALIGN1 = + "\0" + "file not found\0" + "access violation\0" + "disk full\0" + "bad operation\0" + "unknown transfer id\0" + "file already exists\0" + "no such user\0" + "bad option"; + + const char *msg = ""; + + if (len > 4 && rbuf[4] != '\0') { + msg = &rbuf[4]; + rbuf[io_bufsize - 1] = '\0'; /* paranoia */ + } else if (recv_blk <= 8) { + msg = nth_string(errcode_str, recv_blk); } - - if (msg) { - bb_error_msg("server says: %s", msg); - } - - break; + bb_error_msg("server error: (%u) %s", recv_blk, msg); + goto ret; } -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - if (want_option_ack) { - - want_option_ack = 0; +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (expect_OACK) { + expect_OACK = 0; if (opcode == TFTP_OACK) { - /* server seems to support options */ - char *res; - res = tftp_option_get(&buf[2], len - 2, OPTION_BLOCKSIZE); - + res = tftp_get_option("blksize", &rbuf[2], len - 2); if (res) { - int blksize = atoi(res); - - if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) { - - if (cmd & tftp_cmd_put) { - opcode = TFTP_DATA; - } else { - opcode = TFTP_ACK; - } -#ifdef CONFIG_DEBUG_TFTP - fprintf(stderr, "using %s %u\n", OPTION_BLOCKSIZE, - blksize); -#endif - tftp_bufsize = blksize + 4; - block_nr = 0; - continue; + blksize = tftp_blksize_check(res, blksize); + if (blksize < 0) { + G_error_pkt_reason = ERR_BAD_OPT; + goto send_err_pkt; + } + io_bufsize = blksize + 4; + } +# if ENABLE_FEATURE_TFTP_PROGRESS_BAR + if (remote_file && G.size == 0) { /* if we don't know it yet */ + res = tftp_get_option("tsize", &rbuf[2], len - 2); + if (res) { + G.size = bb_strtoull(res, NULL, 10); + if (G.size) + tftp_progress_init(); } } - /* FIXME: - * we should send ERROR 8 */ - bb_error_msg("bad server option"); - break; +# endif + if (CMD_GET(option_mask32)) { + /* We'll send ACK for OACK, + * such ACK has "block no" of 0 */ + block_nr = 0; + } + continue; } - - bb_error_msg("warning: blksize not supported by server" - " - reverting to 512"); - - tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4; + /* rfc2347: + * "An option not acknowledged by the server + * must be ignored by the client and server + * as if it were never requested." */ + if (blksize != TFTP_BLKSIZE_DEFAULT) + bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR); + blksize = TFTP_BLKSIZE_DEFAULT; + io_bufsize = TFTP_BLKSIZE_DEFAULT + 4; } #endif - - if ((cmd & tftp_cmd_get) && (opcode == TFTP_DATA)) { - - if (tmp == block_nr) { - - len = full_write(localfd, &buf[4], len - 4); - - if (len < 0) { - bb_perror_msg(bb_msg_write_error); - break; + /* block_nr is already advanced to next block# we expect + * to get / block# we are about to send next time */ + + if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) { + if (recv_blk == block_nr) { + int sz = full_write(local_fd, &rbuf[4], len - 4); + if (sz != len - 4) { + strcpy(G_error_pkt_str, bb_msg_write_error); + G_error_pkt_reason = ERR_WRITE; + goto send_err_pkt; } - - if (len != (tftp_bufsize - 4)) { - finished++; + if (sz != blksize) { + finished = 1; } - - opcode = TFTP_ACK; - continue; + IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;) + continue; /* send ACK */ } - /* in case the last ack disappeared into the ether */ - if (tmp == (block_nr - 1)) { - --block_nr; - opcode = TFTP_ACK; - continue; - } else if (tmp + 1 == block_nr) { +/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */ +#if 0 + if (recv_blk == (block_nr - 1)) { /* Server lost our TFTP_ACK. Resend it */ - block_nr = tmp; - opcode = TFTP_ACK; + block_nr = recv_blk; continue; } +#endif } - if ((cmd & tftp_cmd_put) && (opcode == TFTP_ACK)) { - - if (tmp == (unsigned short) (block_nr - 1)) { - if (finished) { - break; - } - - opcode = TFTP_DATA; - continue; + if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) { + /* did peer ACK our last DATA pkt? */ + if (recv_blk == (uint16_t) (block_nr - 1)) { + if (finished) + goto ret; + continue; /* send next block */ } } + /* Awww... recv'd packet is not recognized! */ + goto recv_again; + /* why recv_again? - rfc1123 says: + * "The sender (i.e., the side originating the DATA packets) + * must never resend the current DATA packet on receipt + * of a duplicate ACK". + * DATA pkts are resent ONLY on timeout. + * Thus "goto send_again" will ba a bad mistake above. + * See: + * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome + */ + } /* end of "while (1)" */ + ret: + if (ENABLE_FEATURE_CLEAN_UP) { + close(local_fd); + close(socket_fd); + free(xbuf); + free(rbuf); } - -#ifdef CONFIG_FEATURE_CLEAN_UP - close(socketfd); - free(buf); -#endif - - return finished ? EXIT_SUCCESS : EXIT_FAILURE; + return finished == 0; /* returns 1 on failure */ + + send_read_err_pkt: + strcpy(G_error_pkt_str, bb_msg_read_error); + send_err_pkt: + if (G_error_pkt_str[0]) + bb_error_msg("%s", G_error_pkt_str); + G.error_pkt[1] = TFTP_ERROR; + xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str), + &peer_lsa->u.sa, peer_lsa->len); + return EXIT_FAILURE; +#undef remote_file } -int tftp_main(int argc, char **argv) +#if ENABLE_TFTP + +int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tftp_main(int argc UNUSED_PARAM, char **argv) { - struct hostent *host = NULL; - const char *localfile = NULL; - const char *remotefile = NULL; - int port; - int cmd = 0; - int fd = -1; - int flags = 0; + len_and_sockaddr *peer_lsa; + const char *local_file = NULL; + const char *remote_file = NULL; +# if ENABLE_FEATURE_TFTP_BLOCKSIZE + const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR; + int blksize; +# endif int result; - int blocksize = TFTP_BLOCKSIZE_DEFAULT; - - /* figure out what to pass to getopt */ - -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - char *sblocksize = NULL; + int port; + IF_GETPUT(int opt;) + + INIT_G(); + + IF_GETPUT(opt =) getopt32(argv, "^" + IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p") + "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:") + "\0" + /* -p or -g is mandatory, and they are mutually exclusive */ + IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:") + IF_GETPUT("g--p:p--g:"), + &local_file, &remote_file + IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str) + ); + argv += optind; + +# if ENABLE_FEATURE_TFTP_BLOCKSIZE + /* Check if the blksize is valid: + * RFC2348 says between 8 and 65464 */ + blksize = tftp_blksize_check(blksize_str, 65564); + if (blksize < 0) { + //bb_error_msg("bad block size"); + return EXIT_FAILURE; + } +# endif -#define BS "b:" -#define BS_ARG , &sblocksize -#else -#define BS -#define BS_ARG -#endif + if (remote_file) { + if (!local_file) { + const char *slash = strrchr(remote_file, '/'); + local_file = slash ? slash + 1 : remote_file; + } + } else { + remote_file = local_file; + } -#ifdef CONFIG_FEATURE_TFTP_GET -#define GET "g" -#define GET_COMPL ":g" -#else -#define GET -#define GET_COMPL -#endif + /* Error if filename or host is not known */ + if (!remote_file || !argv[0]) + bb_show_usage(); -#ifdef CONFIG_FEATURE_TFTP_PUT -#define PUT "p" -#define PUT_COMPL ":p" -#else -#define PUT -#define PUT_COMPL -#endif + port = bb_lookup_port(argv[1], "udp", 69); + peer_lsa = xhost2sockaddr(argv[0], port); + +# if ENABLE_TFTP_DEBUG + fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n", + xmalloc_sockaddr2dotted(&peer_lsa->u.sa), + remote_file, local_file); +# endif + +# if ENABLE_FEATURE_TFTP_PROGRESS_BAR + G.file = remote_file; +# endif + result = tftp_protocol( + NULL /*our_lsa*/, peer_lsa, + local_file, remote_file + IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */) + IF_FEATURE_TFTP_BLOCKSIZE(, blksize) + ); + tftp_progress_done(); + + if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) { + unlink(local_file); + } + return result; +} -#if defined(CONFIG_FEATURE_TFTP_GET) && defined(CONFIG_FEATURE_TFTP_PUT) - opt_complementary = GET_COMPL PUT_COMPL ":?g--p:p--g"; -#elif defined(CONFIG_FEATURE_TFTP_GET) || defined(CONFIG_FEATURE_TFTP_PUT) - opt_complementary = GET_COMPL PUT_COMPL; -#endif +#endif /* ENABLE_TFTP */ - cmd = getopt32(argc, argv, GET PUT "l:r:" BS, &localfile, &remotefile BS_ARG); +#if ENABLE_TFTPD +int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tftpd_main(int argc UNUSED_PARAM, char **argv) +{ + len_and_sockaddr *our_lsa; + len_and_sockaddr *peer_lsa; + char *mode, *user_opt; + char *local_file = local_file; + const char *error_msg; + int opt, result, opcode; + IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;) + IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;) + + INIT_G(); + + our_lsa = get_sock_lsa(STDIN_FILENO); + if (!our_lsa) { + /* This is confusing: + *bb_error_msg_and_die("stdin is not a socket"); + * Better: */ + bb_show_usage(); + /* Help text says that tftpd must be used as inetd service, + * which is by far the most usual cause of get_sock_lsa + * failure */ + } + peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); + peer_lsa->len = our_lsa->len; + + /* Shifting to not collide with TFTP_OPTs */ + opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8); + argv += optind; + if (opt & TFTPD_OPT_l) { + openlog(applet_name, LOG_PID, LOG_DAEMON); + logmode = LOGMODE_SYSLOG; + } + if (opt & TFTPD_OPT_u) { + /* Must be before xchroot */ + G.pw = xgetpwnam(user_opt); + } + if (argv[0]) { + xchroot(argv[0]); + } - cmd &= (tftp_cmd_get | tftp_cmd_put); -#ifdef CONFIG_FEATURE_TFTP_GET - if (cmd == tftp_cmd_get) - flags = O_WRONLY | O_CREAT | O_TRUNC; -#endif -#ifdef CONFIG_FEATURE_TFTP_PUT - if (cmd == tftp_cmd_put) - flags = O_RDONLY; -#endif + result = recv_from_to(STDIN_FILENO, + G.block_buf, sizeof(G.block_buf) + 1, + /* ^^^ sizeof+1 to reliably detect oversized input */ + 0 /* flags */, + &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); + + error_msg = "malformed packet"; + opcode = ntohs(*(uint16_t*)G.block_buf); + if (result < 4 || result > sizeof(G.block_buf) + /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */ + || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */ + IF_GETPUT(&&) + IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ + ) + ) { + goto err; + } + /* Some HP PA-RISC firmware always sends fixed 516-byte requests, + * with trailing garbage. + * Support that by not requiring NUL to be the last byte (see above). + * To make strXYZ() ops safe, force NUL termination: + */ + G.block_buf_tail[0] = '\0'; -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - if (sblocksize) { - blocksize = atoi(sblocksize); - if (!tftp_blocksize_check(blocksize, 0)) { - return EXIT_FAILURE; + local_file = G.block_buf + 2; + if (local_file[0] == '.' || strstr(local_file, "/.")) { + error_msg = "dot in file name"; + goto err; + } + mode = local_file + strlen(local_file) + 1; + /* RFC 1350 says mode string is case independent */ + if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) { + goto err; + } +# if ENABLE_FEATURE_TFTP_BLOCKSIZE + { + char *res; + char *opt_str = mode + sizeof("octet"); + int opt_len = G.block_buf + result - opt_str; + if (opt_len > 0) { + res = tftp_get_option("blksize", opt_str, opt_len); + if (res) { + blksize = tftp_blksize_check(res, 65564); + if (blksize < 0) { + G_error_pkt_reason = ERR_BAD_OPT; + /* will just send error pkt */ + goto do_proto; + } + } + if (opcode != TFTP_WRQ /* download? */ + /* did client ask us about file size? */ + && tftp_get_option("tsize", opt_str, opt_len) + ) { + want_transfer_size = 1; + } } } -#endif - - if (localfile == NULL) - localfile = remotefile; - if (remotefile == NULL) - remotefile = localfile; - if ((localfile == NULL && remotefile == NULL) || (argv[optind] == NULL)) - bb_show_usage(); - - if (localfile == NULL || strcmp(localfile, "-") == 0) { - fd = (cmd == tftp_cmd_get) ? STDOUT_FILENO : STDIN_FILENO; +# endif + + if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { + if (opt & TFTPD_OPT_r) { + /* This would mean "disk full" - not true */ + /*G_error_pkt_reason = ERR_WRITE;*/ + error_msg = bb_msg_write_error; + goto err; + } + IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ } else { - fd = open(localfile, flags, 0644); /* fail below */ + IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ } - if (fd < 0) { - bb_perror_msg_and_die("local file"); - } - - host = xgethostbyname(argv[optind]); - port = bb_lookup_port(argv[optind + 1], "udp", 69); -#ifdef CONFIG_DEBUG_TFTP - fprintf(stderr, "using server \"%s\", remotefile \"%s\", " - "localfile \"%s\".\n", - inet_ntoa(*((struct in_addr *) host->h_addr)), - remotefile, localfile); -#endif + /* NB: if G_error_pkt_str or G_error_pkt_reason is set up, + * tftp_protocol() just sends one error pkt and returns */ - result = tftp(cmd, host, remotefile, fd, port, blocksize); + do_proto: + close(STDIN_FILENO); /* close old, possibly wildcard socket */ + /* tftp_protocol() will create new one, bound to particular local IP */ + result = tftp_protocol( + our_lsa, peer_lsa, + local_file IF_TFTP(, NULL /*remote_file*/) + IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size) + IF_FEATURE_TFTP_BLOCKSIZE(, blksize) + ); - if (!(fd == STDOUT_FILENO || fd == STDIN_FILENO)) { - if (ENABLE_FEATURE_CLEAN_UP) - close(fd); - if (cmd == tftp_cmd_get && result != EXIT_SUCCESS) - unlink(localfile); - } return result; + err: + strcpy(G_error_pkt_str, error_msg); + goto do_proto; } + +#endif /* ENABLE_TFTPD */ + +#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */