| /* ------------------------------------------------------------------------- */ |
| /* tftp.c */ |
| /* */ |
| /* A simple tftp client for busybox. */ |
| /* Tries to follow RFC1350. */ |
| /* Only "octet" mode and 512-byte data blocks are supported. */ |
| /* */ |
| /* 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 BB_FEATURE_TFTP_DEBUG |
| |
| static const char *tftp_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; |
| |
| static inline int tftp(const int cmd, const struct hostent *host, |
| const char *serverfile, 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; |
| RESERVE_BB_BUFFER(buf, tftp_bufsize + 4); // Why 4 ? |
| |
| tftp_bufsize += 4; |
| |
| if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { |
| 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 = 1; // read request = 1 |
| } |
| |
| if (cmd_put) { |
| opcode = 2; // write request = 2 |
| } |
| |
| while (1) { |
| |
| |
| /* build packet of type "opcode" */ |
| |
| |
| cp = buf; |
| |
| *((unsigned short *) cp) = htons(opcode); |
| |
| cp += 2; |
| |
| /* add filename and mode */ |
| |
| if ((cmd_get && (opcode == 1)) || // read request = 1 |
| (cmd_put && (opcode == 2))) { // write request = 2 |
| |
| /* what is this trying to do ? */ |
| while (cp != &buf[tftp_bufsize - 1]) { |
| if ((*cp = *serverfile++) == '\0') |
| break; |
| cp++; |
| } |
| /* and this ? */ |
| if ((*cp != '\0') || (&buf[tftp_bufsize - 1] - cp) < 7) { |
| error_msg("too long server-filename"); |
| break; |
| } |
| |
| memcpy(cp + 1, "octet", 6); |
| cp += 7; |
| } |
| |
| /* add ack and data */ |
| |
| if ((cmd_get && (opcode == 4)) || // acknowledgement = 4 |
| (cmd_put && (opcode == 3))) { // data packet == 3 |
| |
| *((unsigned short *) cp) = htons(block_nr); |
| |
| cp += 2; |
| |
| block_nr++; |
| |
| if (cmd_put && (opcode == 3)) { // data packet == 3 |
| len = read(localfd, cp, tftp_bufsize - 4); |
| |
| if (len < 0) { |
| perror_msg("read"); |
| break; |
| } |
| |
| if (len != (tftp_bufsize - 4)) { |
| finished++; |
| } |
| |
| cp += len; |
| } else if (finished) { |
| break; |
| } |
| } |
| |
| |
| /* send packet */ |
| |
| |
| do { |
| |
| len = cp - buf; |
| |
| #ifdef BB_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) { |
| perror_msg("send"); |
| len = -1; |
| break; |
| } |
| |
| |
| /* receive packet */ |
| |
| |
| memset(&from, 0, sizeof(from)); |
| fromlen = sizeof(from); |
| |
| tv.tv_sec = 5; // BB_TFPT_TIMEOUT = 5 |
| 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) { |
| 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: |
| error_msg("timeout"); |
| |
| if (timeout == 0) { |
| len = -1; |
| error_msg("last timeout"); |
| } else { |
| timeout--; |
| } |
| break; |
| |
| default: |
| perror_msg("select"); |
| len = -1; |
| } |
| |
| } while (timeout && (len >= 0)); |
| |
| if (len < 0) { |
| break; |
| } |
| |
| /* process received packet */ |
| |
| |
| opcode = ntohs(*((unsigned short *) buf)); |
| tmp = ntohs(*((unsigned short *) &buf[2])); |
| |
| #ifdef BB_FEATURE_TFTP_DEBUG |
| printf("received %d bytes: %04x %04x\n", len, opcode, tmp); |
| #endif |
| |
| if (cmd_get && (opcode == 3)) { // data packet == 3 |
| |
| if (tmp == block_nr) { |
| len = write(localfd, &buf[4], len - 4); |
| |
| if (len < 0) { |
| perror_msg("write"); |
| break; |
| } |
| |
| if (len != (tftp_bufsize - 4)) { |
| finished++; |
| } |
| |
| opcode = 4; // acknowledgement = 4 |
| continue; |
| } |
| } |
| |
| if (cmd_put && (opcode == 4)) { // acknowledgement = 4 |
| |
| if (tmp == (block_nr - 1)) { |
| if (finished) { |
| break; |
| } |
| |
| opcode = 3; // data packet == 3 |
| continue; |
| } |
| } |
| |
| if (opcode == 5) { // error code == 5 |
| char *msg = NULL; |
| |
| if (buf[4] != '\0') { |
| msg = &buf[4]; |
| buf[tftp_bufsize - 1] = '\0'; |
| } else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) { |
| msg = (char *) tftp_error_msg[tmp]; |
| } |
| |
| if (msg) { |
| error_msg("server says: %s", msg); |
| } |
| |
| break; |
| } |
| } |
| |
| close(socketfd); |
| |
| 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 = 512; |
| |
| while ((opt = getopt(argc, argv, "b:gpl:r:")) != -1) { |
| switch (opt) { |
| case 'b': |
| blocksize = atoi(optarg); |
| break; |
| #ifdef BB_FEATURE_TFTP_GET |
| case 'g': |
| cmd = tftp_cmd_get; |
| flags = O_WRONLY | O_CREAT; |
| break; |
| #endif |
| #ifdef BB_FEATURE_TFTP_PUT |
| case 'p': |
| cmd = tftp_cmd_put; |
| flags = O_RDONLY; |
| break; |
| #endif |
| case 'l': |
| localfile = xstrdup(optarg); |
| break; |
| case 'r': |
| remotefile = xstrdup(optarg); |
| break; |
| } |
| } |
| |
| if ((cmd == 0) || (optind == argc)) { |
| show_usage(); |
| } |
| |
| fd = open(localfile, flags, 0644); |
| if (fd < 0) { |
| perror_msg_and_die("local file"); |
| } |
| |
| host = xgethostbyname(argv[optind]); |
| |
| if (optind + 2 == argc) { |
| port = atoi(argv[optind + 1]); |
| } |
| |
| #ifdef BB_FEATURE_TFTP_DEBUG |
| printf("using server \"%s\", serverfile \"%s\"," |
| "localfile \"%s\".\n", |
| inet_ntoa(*((struct in_addr *) host->h_addr)), |
| remotefile, localfile); |
| #endif |
| |
| result = tftp(cmd, host, remotefile, fd, port, blocksize); |
| close(fd); |
| |
| return(result); |
| } |
