/* ------------------------------------------------------------------------- */ /* tftp.c */ /* */ /* A simple tftp client for busybox. */ /* Tries to follow RFC1350. */ /* Only "octet" mode supported. */ /* Optional blocksize negotiation (RFC2347 + RFC2348) */ /* */ /* Copyright (C) 2001 Magnus Damm <damm@opensource.se> */ /* */ /* Parts of the code based on: */ /* */ /* atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca> */ /* and Remi Lefebvre <remi@debian.org> */ /* */ /* utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> */ /* */ /* This program is free software; you can redistribute it and/or modify */ /* it under the terms of the GNU General Public License as published by */ /* the Free Software Foundation; either version 2 of the License, or */ /* (at your option) any later version. */ /* */ /* This program is distributed in the hope that it will be useful, */ /* but WITHOUT ANY WARRANTY; without even the implied warranty of */ /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU */ /* General Public License for more details. */ /* */ /* You should have received a copy of the GNU General Public License */ /* along with this program; if not, write to the Free Software */ /* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* */ /* ------------------------------------------------------------------------- */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/time.h> #include <sys/stat.h> #include <netdb.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <fcntl.h> #include "busybox.h" //#define CONFIG_FEATURE_TFTP_DEBUG #define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ #define TFTP_TIMEOUT 5 /* seconds */ /* opcodes we support */ #define TFTP_RRQ 1 #define TFTP_WRQ 2 #define TFTP_DATA 3 #define TFTP_ACK 4 #define TFTP_ERROR 5 #define TFTP_OACK 6 static const char *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" }; const int tftp_cmd_get = 1; const int tftp_cmd_put = 2; #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE static int tftp_blocksize_check(int blocksize, int bufsize) { /* Check if the blocksize 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 > 65464)) { bb_error_msg("bad blocksize"); return 0; } return blocksize; } static char *tftp_option_get(char *buf, int len, char *option) { int opt_val = 0; int opt_found = 0; int k; while (len > 0) { /* Make sure the options are terminated correctly */ for (k = 0; k < len; k++) { if (buf[k] == '\0') { break; } } if (k >= len) { break; } if (opt_val == 0) { if (strcasecmp(buf, option) == 0) { opt_found = 1; } } else { if (opt_found) { return buf; } } k++; buf += k; len -= k; opt_val ^= 1; } return NULL; } #endif static inline int tftp(const int cmd, const struct hostent *host, const char *remotefile, int localfd, const int port, int tftp_bufsize) { const int cmd_get = cmd & tftp_cmd_get; const int cmd_put = cmd & tftp_cmd_put; const int bb_tftp_num_retries = 5; struct sockaddr_in sa; struct sockaddr_in from; struct timeval tv; socklen_t fromlen; fd_set rfds; char *cp; unsigned short tmp; int socketfd; int len; int opcode = 0; int finished = 0; int timeout = bb_tftp_num_retries; int block_nr = 1; #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE int want_option_ack = 0; #endif /* 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); tftp_bufsize += 4; if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { bb_perror_msg("socket"); return EXIT_FAILURE; } len = sizeof(sa); memset(&sa, 0, len); bind(socketfd, (struct sockaddr *)&sa, len); sa.sin_family = host->h_addrtype; sa.sin_port = htons(port); memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr, sizeof(sa.sin_addr)); /* build opcode */ if (cmd_get) { opcode = TFTP_RRQ; } if (cmd_put) { opcode = TFTP_WRQ; } while (1) { cp = buf; /* first create the opcode part */ *((unsigned short *) cp) = htons(opcode); cp += 2; /* add filename and mode */ if ((cmd_get && (opcode == TFTP_RRQ)) || (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) < 6)) { bb_error_msg("too long remote-filename"); break; } /* add "mode" part of the package */ memcpy(cp, "octet", 6); cp += 6; #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("too long remote-filename"); break; } /* add "blksize" + number of blocks */ memcpy(cp, "blksize", 8); cp += 8; cp += snprintf(cp, 6, "%d", len) + 1; want_option_ack = 1; } #endif } /* add ack and data */ if ((cmd_get && (opcode == TFTP_ACK)) || (cmd_put && (opcode == TFTP_DATA))) { *((unsigned short *) cp) = htons(block_nr); cp += 2; block_nr++; if (cmd_put && (opcode == TFTP_DATA)) { len = read(localfd, cp, tftp_bufsize - 4); if (len < 0) { bb_perror_msg("read"); break; } if (len != (tftp_bufsize - 4)) { finished++; } cp += len; } } /* send packet */ do { len = cp - buf; #ifdef CONFIG_FEATURE_TFTP_DEBUG printf("sending %u bytes\n", len); for (cp = buf; cp < &buf[len]; cp++) printf("%02x ", *cp); printf("\n"); #endif if (sendto(socketfd, buf, len, 0, (struct sockaddr *) &sa, sizeof(sa)) < 0) { bb_perror_msg("send"); len = -1; break; } if (finished) { break; } /* 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(FD_SETSIZE, &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 == htons(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 = bb_tftp_num_retries; case 0: bb_error_msg("timeout"); if (timeout == 0) { len = -1; bb_error_msg("last timeout"); } else { timeout--; } break; default: bb_perror_msg("select"); len = -1; } } 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_FEATURE_TFTP_DEBUG printf("received %d bytes: %04x %04x\n", len, opcode, tmp); #endif if (opcode == TFTP_ERROR) { 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 = (char *) tftp_bb_error_msg[tmp]; } if (msg) { bb_error_msg("server says: %s", msg); } break; } #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE if (want_option_ack) { want_option_ack = 0; if (opcode == TFTP_OACK) { /* server seems to support options */ char *res; res = tftp_option_get(&buf[2], len-2, "blksize"); if (res) { int blksize = atoi(res); if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) { if (cmd_put) { opcode = TFTP_DATA; } else { opcode = TFTP_ACK; } #ifdef CONFIG_FEATURE_TFTP_DEBUG printf("using blksize %u\n", blksize); #endif tftp_bufsize = blksize + 4; block_nr = 0; continue; } } /* FIXME: * we should send ERROR 8 */ bb_error_msg("bad server option"); break; } bb_error_msg("warning: blksize not supported by server" " - reverting to 512"); tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4; } #endif if (cmd_get && (opcode == TFTP_DATA)) { if (tmp == block_nr) { len = write(localfd, &buf[4], len - 4); if (len < 0) { bb_perror_msg("write"); break; } if (len != (tftp_bufsize - 4)) { finished++; } opcode = TFTP_ACK; continue; } } if (cmd_put && (opcode == TFTP_ACK)) { if (tmp == (block_nr - 1)) { if (finished) { break; } opcode = TFTP_DATA; continue; } } } #ifdef CONFIG_FEATURE_CLEAN_UP close(socketfd); free(buf); #endif return finished ? EXIT_SUCCESS : EXIT_FAILURE; } int tftp_main(int argc, char **argv) { struct hostent *host = NULL; char *localfile = NULL; char *remotefile = NULL; int port = 69; int cmd = 0; int fd = -1; int flags = 0; int opt; int result; int blocksize = TFTP_BLOCKSIZE_DEFAULT; /* figure out what to pass to getopt */ #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE #define BS "b:" #else #define BS #endif #ifdef CONFIG_FEATURE_TFTP_GET #define GET "g" #else #define GET #endif #ifdef CONFIG_FEATURE_TFTP_PUT #define PUT "p" #else #define PUT #endif while ((opt = getopt(argc, argv, BS GET PUT "l:r:")) != -1) { switch (opt) { #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE case 'b': blocksize = atoi(optarg); if (!tftp_blocksize_check(blocksize, 0)) { return EXIT_FAILURE; } break; #endif #ifdef CONFIG_FEATURE_TFTP_GET case 'g': cmd = tftp_cmd_get; flags = O_WRONLY | O_CREAT; break; #endif #ifdef CONFIG_FEATURE_TFTP_PUT case 'p': cmd = tftp_cmd_put; flags = O_RDONLY; break; #endif case 'l': localfile = bb_xstrdup(optarg); break; case 'r': remotefile = bb_xstrdup(optarg); break; } } if ((cmd == 0) || (optind == argc)) { bb_show_usage(); } if(localfile && strcmp(localfile, "-") == 0) { fd = fileno((cmd==tftp_cmd_get)? stdout : stdin); } if(localfile == NULL) localfile = remotefile; if(remotefile == NULL) remotefile = localfile; if (fd==-1) { fd = open(localfile, flags, 0644); } if (fd < 0) { bb_perror_msg_and_die("local file"); } host = xgethostbyname(argv[optind]); if (optind + 2 == argc) { port = atoi(argv[optind + 1]); } #ifdef CONFIG_FEATURE_TFTP_DEBUG printf("using server \"%s\", remotefile \"%s\", " "localfile \"%s\".\n", inet_ntoa(*((struct in_addr *) host->h_addr)), remotefile, localfile); #endif result = tftp(cmd, host, remotefile, fd, port, blocksize); #ifdef CONFIG_FEATURE_CLEAN_UP if (!(fd == fileno(stdout) || fd == fileno(stdin))) { close(fd); } #endif return(result); }