diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2008-03-17 12:10:39 +0300 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2008-03-17 12:10:39 +0300 |
commit | aa9b1828b91bc4b60f1164b7929a6a0ac091419e (patch) | |
tree | 31a2278e3998160a7c40ac5882736a2f48768a2d /networking/tftp.c | |
parent | 1d42665b6b0571b9fa5d3b10fbf2dd03382f0ba2 (diff) |
tftpd: new applet (mostly using existing code for tftp)
function old new delta
tftp_protocol - 1173 +1173
tftpd_main - 500 +500
tftp_option_get - 102 +102
packed_usage 23650 23662 +12
applet_names 1809 1815 +6
applet_main 1100 1104 +4
applet_nameofs 550 552 +2
tftp_main 302 301 -1
get_nport 32 - -32
tftp 1172 - -1172
------------------------------------------------------------------------------
(add/remove: 3/2 grow/shrink: 4/1 up/down: 1799/-1205) Total: 594 bytes
text data bss dec hex filename
796479 662 7420 804561 c46d1 busybox_old
797153 662 7420 805235 c4973 busybox_unstripped
Diffstat (limited to 'networking/tftp.c')
-rw-r--r-- | networking/tftp.c | 334 |
1 files changed, 242 insertions, 92 deletions
diff --git a/networking/tftp.c b/networking/tftp.c index 187261568..23a24139b 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -2,7 +2,7 @@ /* ------------------------------------------------------------------------- * 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) @@ -16,6 +16,8 @@ * * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> * + * tftpd added by Denys Vlasenko + * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. * ------------------------------------------------------------------------- */ @@ -46,7 +48,7 @@ #define CMD_PUT(cmd) 1 #else #define USE_GETPUT(...) __VA_ARGS__ -/* masks coming from getpot32 */ +/* masks coming from getopt32 */ #define CMD_GET(cmd) ((cmd) & 1) #define CMD_PUT(cmd) ((cmd) & 2) #endif @@ -64,14 +66,12 @@ static int tftp_blocksize_check(int blocksize, int bufsize) * but our implementation makes it impossible * to use blocksizes smaller than 22 octets. */ - if ((bufsize && (blocksize > bufsize)) - || (blocksize < 8) || (blocksize > 65564) + || (blocksize < 24) || (blocksize > 65564) ) { bb_error_msg("bad blocksize"); return 0; } - return blocksize; } @@ -81,8 +81,11 @@ static char *tftp_option_get(char *buf, int len, const char *option) int opt_found = 0; int k; + /* buf points to: + * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */ + while (len > 0) { - /* Make sure the options are terminated correctly */ + /* Make sure options are terminated correctly */ for (k = 0; k < len; k++) { if (buf[k] == '\0') { goto nul_found; @@ -90,7 +93,7 @@ static char *tftp_option_get(char *buf, int len, const char *option) } return NULL; nul_found: - if (opt_val == 0) { + if (opt_val == 0) { /* it's "name" part */ if (strcasecmp(buf, option) == 0) { opt_found = 1; } @@ -109,77 +112,116 @@ static char *tftp_option_get(char *buf, int len, const char *option) #endif -static int tftp( USE_GETPUT(const int cmd,) +static int tftp_protocol( + USE_GETPUT(int cmd,) + len_and_sockaddr *our_lsa, len_and_sockaddr *peer_lsa, - const char *remotefile, const int localfd, - unsigned port, int tftp_bufsize) + USE_TFTP(const char *remote_file,) + int local_fd, + int blocksize) { +#if !ENABLE_TFTP +#define remote_file NULL +#endif struct pollfd pfd[1]; -#define socketfd (pfd[0].fd) +#define socket_fd (pfd[0].fd) int len; int send_len; USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;) smallint finished = 0; uint16_t opcode; - uint16_t block_nr = 1; + uint16_t block_nr; uint16_t recv_blk; int retries, waittime_ms; + int tftp_bufsize = blocksize + 4; char *cp; - - unsigned org_port; - len_and_sockaddr *const from = alloca(LSA_LEN_SIZE + peer_lsa->len); - /* Can't use RESERVE_CONFIG_BUFFER here since the allocation * size varies meaning BUFFERS_GO_ON_STACK would fail */ /* We must keep the transmit and receive buffers seperate */ /* In case we rcv a garbage pkt and we need to rexmit the last pkt */ - char *xbuf = xmalloc(tftp_bufsize += 4); + char *xbuf = xmalloc(tftp_bufsize); char *rbuf = xmalloc(tftp_bufsize); - port = org_port = htons(port); + socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); + setsockopt_reuseaddr(socket_fd); - socketfd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); + if (!ENABLE_TFTP || our_lsa) { + /* tftpd */ + block_nr = 0; - /* build opcode */ - opcode = TFTP_WRQ; - if (CMD_GET(cmd)) { - opcode = TFTP_RRQ; - } - cp = xbuf + 2; - /* add filename and mode */ - /* fill in packet if the filename fits into xbuf */ - len = strlen(remotefile) + 1; - if (2 + len + sizeof("octet") >= tftp_bufsize) { - bb_error_msg("remote filename is too long"); - goto ret; - } - strcpy(cp, remotefile); - cp += len; - /* add "mode" part of the package */ - strcpy(cp, "octet"); - cp += sizeof("octet"); + /* 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); #if ENABLE_FEATURE_TFTP_BLOCKSIZE - len = tftp_bufsize - 4; /* data block size */ - if (len != TFTP_BLOCKSIZE_DEFAULT) { - /* rfc2348 says that 65464 is a max allowed value */ - if ((&xbuf[tftp_bufsize - 1] - cp) < sizeof("blksize NNNNN")) { + if (blocksize != TFTP_BLOCKSIZE_DEFAULT) { + /* Create and send OACK packet */ + opcode = TFTP_OACK; + cp = xbuf + 2; + goto add_blksize_opt; + } + /* else: just fall into while (1) loop below */ +#endif + } else { + /* tftp */ + block_nr = 1; + + /* 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(cmd)) { + opcode = TFTP_RRQ; + } + cp = xbuf + 2; + /* add filename and mode */ + /* fill in packet if the filename fits into xbuf */ + len = strlen(remote_file) + 1; + if (2 + len + sizeof("octet") >= tftp_bufsize) { bb_error_msg("remote filename is too long"); goto ret; } - /* add "blksize", <nul>, blocksize */ - strcpy(cp, "blksize"); - cp += sizeof("blksize"); - cp += snprintf(cp, 6, "%d", len) + 1; - want_option_ack = 1; - } + strcpy(cp, remote_file); + cp += len; + /* add "mode" part of the package */ + strcpy(cp, "octet"); + cp += sizeof("octet"); + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (blocksize != TFTP_BLOCKSIZE_DEFAULT) { + /* rfc2348 says that 65464 is a max allowed value */ + if ((&xbuf[tftp_bufsize - 1] - cp) < sizeof("blksize NNNNN")) { + bb_error_msg("remote filename is too long"); + goto ret; + } + want_option_ack = 1; + add_blksize_opt: + /* add "blksize", <nul>, blocksize, <nul> */ + strcpy(cp, "blksize"); + cp += sizeof("blksize"); + cp += snprintf(cp, 6, "%d", blocksize) + 1; + } #endif - /* First packet is built, so skip packet generation */ - goto send_pkt; + /* 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) { /* Build ACK or DATA */ cp = xbuf + 2; @@ -189,7 +231,7 @@ static int tftp( USE_GETPUT(const int cmd,) opcode = TFTP_ACK; if (CMD_PUT(cmd)) { opcode = TFTP_DATA; - len = full_read(localfd, cp, tftp_bufsize - 4); + len = full_read(local_fd, cp, tftp_bufsize - 4); if (len < 0) { bb_perror_msg(bb_msg_read_error); goto ret; @@ -216,36 +258,36 @@ static int tftp( USE_GETPUT(const int cmd,) fprintf(stderr, "%02x ", (unsigned char) *cp); fprintf(stderr, "\n"); #endif - xsendto(socketfd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); + xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); /* Was it final ACK? then exit */ if (finished && (opcode == TFTP_ACK)) goto ret; recv_again: /* Receive packet */ - /*pfd[0].fd = socketfd;*/ + /*pfd[0].fd = socket_fd;*/ pfd[0].events = POLLIN; switch (safe_poll(pfd, 1, waittime_ms)) { - unsigned from_port; case 1: - from->len = peer_lsa->len; - memset(&from->u.sa, 0, peer_lsa->len); - len = recvfrom(socketfd, rbuf, tftp_bufsize, 0, - &from->u.sa, &from->len); + if (!our_lsa) { + /* tftp (not tftpd!) receiving 1st packet */ + our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */ + len = recvfrom(socket_fd, rbuf, tftp_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. */ + len = safe_read(socket_fd, rbuf, tftp_bufsize); + } if (len < 0) { - bb_perror_msg("recvfrom"); + bb_perror_msg("read"); goto ret; } - from_port = get_nport(&from->u.sa); - if (port == org_port) { - /* Our first query went to port 69 - * but reply will come from different one. - * Remember and use this new port */ - port = from_port; - set_nport(peer_lsa, from_port); - } - if (port != from_port) - goto recv_again; goto process_pkt; case 0: retries--; @@ -316,7 +358,7 @@ static int tftp( USE_GETPUT(const int cmd,) /*static const uint16_t error_8[2] = { htons(TFTP_ERROR), htons(8) };*/ /* thus we open-code big-endian layout */ static const uint8_t error_8[4] = { 0,TFTP_ERROR, 0,8 }; - xsendto(socketfd, error_8, 4, &peer_lsa->u.sa, peer_lsa->len); + xsendto(socket_fd, error_8, 4, &peer_lsa->u.sa, peer_lsa->len); bb_error_msg("server proposes bad blksize %d, exiting", blksize); goto ret; } @@ -345,7 +387,7 @@ static int tftp( USE_GETPUT(const int cmd,) if (CMD_GET(cmd) && (opcode == TFTP_DATA)) { if (recv_blk == block_nr) { - len = full_write(localfd, &rbuf[4], len - 4); + len = full_write(local_fd, &rbuf[4], len - 4); if (len < 0) { bb_perror_msg(bb_msg_write_error); goto ret; @@ -363,7 +405,7 @@ static int tftp( USE_GETPUT(const int cmd,) } if (CMD_PUT(cmd) && (opcode == TFTP_ACK)) { - /* did server ACK our last DATA pkt? */ + /* did peer ACK our last DATA pkt? */ if (recv_blk == (uint16_t) (block_nr - 1)) { if (finished) goto ret; @@ -381,25 +423,27 @@ static int tftp( USE_GETPUT(const int cmd,) * See: * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome */ - } + } /* end of "while (1)" */ ret: if (ENABLE_FEATURE_CLEAN_UP) { - close(socketfd); + close(socket_fd); free(xbuf); free(rbuf); } return finished == 0; /* returns 1 on failure */ } +#if ENABLE_TFTP + int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) { len_and_sockaddr *peer_lsa; - const char *localfile = NULL; - const char *remotefile = NULL; + const char *local_file = NULL; + const char *remote_file = NULL; int port; USE_GETPUT(int cmd;) - int fd = -1; + int local_fd; int flags = 0; int result; int blocksize = TFTP_BLOCKSIZE_DEFAULT; @@ -412,7 +456,7 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) USE_GETPUT(cmd =) getopt32(argv, USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p") "l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"), - &localfile, &remotefile + &local_file, &remote_file USE_FEATURE_TFTP_BLOCKSIZE(, &blocksize)); argv += optind; @@ -425,36 +469,142 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) return EXIT_FAILURE; #endif - if (!localfile) - localfile = remotefile; - if (!remotefile) - remotefile = localfile; + if (!local_file) + local_file = remote_file; + if (!remote_file) + remote_file = local_file; /* Error if filename or host is not known */ - if (!remotefile || !argv[0]) + if (!remote_file || !argv[0]) bb_show_usage(); - fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO; - if (!LONE_DASH(localfile)) { - fd = xopen(localfile, flags); + local_fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO; + if (!LONE_DASH(local_file)) { + local_fd = xopen(local_file, flags); } port = bb_lookup_port(argv[1], "udp", 69); peer_lsa = xhost2sockaddr(argv[0], port); #if ENABLE_DEBUG_TFTP - fprintf(stderr, "using server '%s', remotefile '%s', localfile '%s'\n", + fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n", xmalloc_sockaddr2dotted(&peer_lsa->u.sa), - remotefile, localfile); + remote_file, local_file); #endif - result = tftp( USE_GETPUT(cmd,) peer_lsa, remotefile, fd, port, blocksize); + result = tftp_protocol( + USE_GETPUT(cmd,) + NULL /* our_lsa*/, + peer_lsa, + remote_file, local_fd, blocksize); if (ENABLE_FEATURE_CLEAN_UP) - close(fd); - if (result != EXIT_SUCCESS && !LONE_DASH(localfile) && CMD_GET(cmd)) { - unlink(localfile); + close(local_fd); + if (result != EXIT_SUCCESS && !LONE_DASH(local_file) && CMD_GET(cmd)) { + unlink(local_file); } return result; } +#endif /* ENABLE_TFTP */ + +#if ENABLE_TFTPD + +/* TODO: libbb candidate? */ +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; +} + +int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) +{ + struct stat statbuf; + char block_buf[TFTP_BLOCKSIZE_DEFAULT]; + len_and_sockaddr *our_lsa; + len_and_sockaddr *peer_lsa; + char *filename, *mode, *opt_str; + int result, opcode, cmd, req_modebits, open_mode, local_fd, blksize; + + our_lsa = get_sock_lsa(STDIN_FILENO); + if (!our_lsa) + bb_perror_msg_and_die("stdin is not a socket"); + peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); + peer_lsa->len = our_lsa->len; + + if (argv[1]) + xchdir(argv[1]); + + result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf), + 0 /* flags */, + &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); + + opcode = ntohs(*(uint16_t*)block_buf); + if (result < 4 || result >= sizeof(block_buf) + || block_buf[result-1] != '\0' + || (opcode != TFTP_RRQ && opcode != TFTP_WRQ) + ) { + bb_error_msg_and_die("malformed packet"); + } + filename = block_buf + 2; + if (filename[0] == '.' || strstr(filename, "/.")) { + bb_error_msg_and_die("dot in filename"); + } + mode = filename + strlen(filename) + 1; + if (mode >= block_buf + sizeof(block_buf) + || strcmp(mode, "octet") != 0 + ) { + bb_error_msg_and_die("malformed packet"); + } + blksize = TFTP_BLOCKSIZE_DEFAULT; +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + opt_str = mode + 6; + if (opt_str < block_buf + sizeof(block_buf)) { + char *res = tftp_option_get(opt_str, block_buf + sizeof(block_buf) - opt_str, "blksize"); + if (res) { + int sz = xatoi_u(res); + if (tftp_blocksize_check(sz, 0)) + blksize = sz; + } + } +#endif + xstat(filename, &statbuf); + /* if opcode == TFTP_WRQ: */ + cmd = 1; /* CMD_GET: we will receive file's data */ + req_modebits = 0222; /* writable by anyone */ + open_mode = O_WRONLY | O_TRUNC; + if (opcode == TFTP_RRQ) { + cmd = 2; /* CMD_PUT */ + req_modebits = 0444; /* readable by anyone */ + open_mode = O_RDONLY; + } + if (!S_ISREG(statbuf.st_mode) + || (statbuf.st_mode & req_modebits) != req_modebits + ) { + bb_error_msg_and_die("access to '%s' is denied", filename); + } + local_fd = xopen(filename, open_mode); + + close(STDIN_FILENO); /* close old, possibly wildcard socket */ + /* tftp_protocol() will create new one, bound to particular local IP */ + result = tftp_protocol( + USE_GETPUT(cmd,) + our_lsa, peer_lsa, + USE_TFTP(NULL /*remote_file*/,) + local_fd, + blksize + ); + + return result; +} + +#endif /* ENABLE_TFTPD */ + #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */ |