/* ------------------------------------------------------------------------- */ /* 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 /* we don't need #ifdefs with these constants and optimization... */ #ifdef BB_FEATURE_TFTP_GET #define BB_TFTP_GET (1 << 0) #else #define BB_TFTP_GET 0 #endif #ifdef BB_FEATURE_TFTP_PUT #define BB_TFTP_PUT (1 << 1) #else #define BB_TFTP_PUT 0 #endif #ifdef BB_FEATURE_TFTP_DEBUG #define BB_TFTP_DEBUG 1 #else #define BB_TFTP_DEBUG 0 #endif #define BB_TFTP_NO_RETRIES 5 #define BB_TFTP_TIMEOUT 5 /* seconds */ #define RRQ 1 /* read request */ #define WRQ 2 /* write request */ #define DATA 3 /* data packet */ #define ACK 4 /* acknowledgement */ #define ERROR 5 /* error code */ #define BUFSIZE (512+4) 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" }; static inline int tftp(int cmd, struct hostent *host, char *serverfile, int localfd, int port) { struct sockaddr_in sa; int socketfd; struct timeval tv; fd_set rfds; struct sockaddr_in from; socklen_t fromlen; char *cp; unsigned short tmp; int len, opcode, finished; int timeout, block_nr; RESERVE_BB_BUFFER(buf, BUFSIZE); opcode = finished = timeout = 0; block_nr = 1; 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 & BB_TFTP_GET) { opcode = RRQ; } if (cmd & BB_TFTP_PUT) { opcode = WRQ; } while (1) { /* build packet of type "opcode" */ cp = buf; *((unsigned short *) cp) = htons(opcode); cp += 2; /* add filename and mode */ if ((BB_TFTP_GET && (opcode == RRQ)) || (BB_TFTP_PUT && (opcode == WRQ))) { while (cp != &buf[BUFSIZE - 1]) { if ((*cp = *serverfile++) == '\0') break; cp++; } if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) { error_msg("too long server-filename"); break; } memcpy(cp + 1, "octet", 6); cp += 7; } /* add ack and data */ if ((BB_TFTP_GET && (opcode == ACK)) || (BB_TFTP_PUT && (opcode == DATA))) { *((unsigned short *) cp) = htons(block_nr); cp += 2; block_nr++; if (BB_TFTP_PUT && (opcode == DATA)) { len = read(localfd, cp, BUFSIZE - 4); if (len < 0) { perror_msg("read"); break; } if (len != (BUFSIZE - 4)) { finished++; } cp += len; } else if (finished) { break; } } /* send packet */ do { len = cp - buf; if (BB_TFTP_DEBUG) { printf("sending %u bytes\n", len); for (cp = buf; cp < &buf[len]; cp++) printf("%02x ", *cp); printf("\n"); } 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 = BB_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, 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; break; } if (sa.sin_port == from.sin_port) { break; } /* fall-through for bad packets! */ /* discard the packet - treat as timeout */ case 0: error_msg("timeout"); if (!timeout) { timeout = BB_TFTP_NO_RETRIES; } else { timeout--; } if (!timeout) { len = -1; error_msg("last 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])); if (BB_TFTP_DEBUG) { printf("received %d bytes: %04x %04x\n", len, opcode, tmp); } if (BB_TFTP_GET && (opcode == DATA)) { if (tmp == block_nr) { len = write(localfd, &buf[4], len - 4); if (len < 0) { perror_msg("write"); break; } if (len != (BUFSIZE - 4)) { finished++; } opcode = ACK; continue; } } if (BB_TFTP_PUT && (opcode == ACK)) { if (tmp == (block_nr - 1)) { if (finished) { break; } opcode = DATA; continue; } } if (opcode == ERROR) { char *msg = NULL; if (buf[4] != '\0') { msg = &buf[4]; buf[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) { char *cp, *s; char *serverstr; struct hostent *host; char *serverfile; char *localfile; int cmd, flags, fd, bad; host = (void *) serverstr = serverfile = localfile = NULL; flags = cmd = 0; bad = 1; if (argc > 3) { if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) { cmd = BB_TFTP_GET; flags = O_WRONLY | O_CREAT; serverstr = argv[2]; localfile = argv[3]; } if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) { cmd = BB_TFTP_PUT; flags = O_RDONLY; localfile = argv[2]; serverstr = argv[3]; } } if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) { show_usage(); } for (cp = serverstr; *cp != '\0'; cp++) if (*cp == ':') break; if (*cp == ':') { serverfile = cp + 1; s = xstrdup(serverstr); s[cp - serverstr] = '\0'; if ((host = gethostbyname(s))) { bad = 0; } free(s); } if (bad) { error_msg_and_die("bad \"server:file\" combination"); } if (BB_TFTP_DEBUG) { printf("using server \"%s\", serverfile \"%s\"," "localfile \"%s\".\n", inet_ntoa(*((struct in_addr *) host->h_addr)), serverfile, localfile); } if ((fd = open(localfile, flags, 0644)) < 0) { perror_msg_and_die("local file"); } flags = tftp(cmd, host, serverfile, fd, 69); close(fd); return flags; }