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-rw-r--r--networking/tftp.c561
1 files changed, 561 insertions, 0 deletions
diff --git a/networking/tftp.c b/networking/tftp.c
new file mode 100644
index 000000000..64d376fa7
--- /dev/null
+++ b/networking/tftp.c
@@ -0,0 +1,561 @@
+/* vi: set sw=4 ts=4: */
+/* -------------------------------------------------------------------------
+ * 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>
+ *
+ * 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) */
+
+/* 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 *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"
+};
+
+#define tftp_cmd_get ENABLE_FEATURE_TFTP_GET
+
+#if ENABLE_FEATURE_TFTP_PUT
+# define tftp_cmd_put (tftp_cmd_get+ENABLE_FEATURE_TFTP_PUT)
+#else
+# define tftp_cmd_put 0
+#endif
+
+
+#if ENABLE_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 > 65564)) {
+ bb_error_msg("bad blocksize");
+ return 0;
+ }
+
+ return blocksize;
+}
+
+static char *tftp_option_get(char *buf, int len, const char * const 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 int tftp(const int cmd, const struct hostent *host,
+ const char *remotefile, const int localfd,
+ const unsigned short port, int tftp_bufsize)
+{
+ struct sockaddr_in sa;
+ struct sockaddr_in from;
+ struct timeval tv;
+ socklen_t fromlen;
+ fd_set rfds;
+ int socketfd;
+ int len;
+ int opcode = 0;
+ int finished = 0;
+ int timeout = TFTP_NUM_RETRIES;
+ unsigned short block_nr = 1;
+ unsigned short tmp;
+ 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;
+ }
+
+ 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;
+ }
+ if (cmd & tftp_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 & 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;
+
+#if ENABLE_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;
+ }
+#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;
+ }
+ }
+
+
+ /* send packet */
+
+
+ timeout = TFTP_NUM_RETRIES; /* re-initialize */
+ do {
+
+ len = cp - buf;
+
+#if ENABLE_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");
+#endif
+ if (sendto(socketfd, buf, len, 0,
+ (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+ bb_perror_msg("send");
+ len = -1;
+ break;
+ }
+
+
+ if (finished && (opcode == TFTP_ACK)) {
+ 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(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;
+ }
+
+ } while (timeout && (len >= 0));
+
+ if ((finished) || (len < 0)) {
+ break;
+ }
+
+ /* process received packet */
+
+ opcode = ntohs(*((unsigned short *) buf));
+ tmp = ntohs(*((unsigned short *) &buf[2]));
+
+#if ENABLE_DEBUG_TFTP
+ fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp);
+#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];
+ }
+
+ if (msg) {
+ bb_error_msg("server says: %s", msg);
+ }
+
+ break;
+ }
+#if ENABLE_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, OPTION_BLOCKSIZE);
+
+ if (res) {
+ int blksize = xatoi_u(res);
+
+ if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
+
+ if (cmd & tftp_cmd_put) {
+ opcode = TFTP_DATA;
+ } else {
+ opcode = TFTP_ACK;
+ }
+#if ENABLE_DEBUG_TFTP
+ fprintf(stderr, "using %s %u\n", OPTION_BLOCKSIZE,
+ 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 & 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;
+ }
+
+ if (len != (tftp_bufsize - 4)) {
+ finished++;
+ }
+
+ opcode = TFTP_ACK;
+ continue;
+ }
+ /* 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) {
+ /* Server lost our TFTP_ACK. Resend it */
+ block_nr = tmp;
+ opcode = TFTP_ACK;
+ continue;
+ }
+ }
+
+ if ((cmd & tftp_cmd_put) && (opcode == TFTP_ACK)) {
+
+ if (tmp == (unsigned short) (block_nr - 1)) {
+ if (finished) {
+ break;
+ }
+
+ opcode = TFTP_DATA;
+ continue;
+ }
+ }
+ }
+
+#if ENABLE_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;
+ const char *localfile = NULL;
+ const char *remotefile = NULL;
+ int port;
+ int cmd = 0;
+ int fd = -1;
+ int flags = 0;
+ int result;
+ int blocksize = TFTP_BLOCKSIZE_DEFAULT;
+
+ /* figure out what to pass to getopt */
+
+#if ENABLE_FEATURE_TFTP_BLOCKSIZE
+ char *sblocksize = NULL;
+
+#define BS "b:"
+#define BS_ARG , &sblocksize
+#else
+#define BS
+#define BS_ARG
+#endif
+
+#if ENABLE_FEATURE_TFTP_GET
+#define GET "g"
+#define GET_COMPL ":g"
+#else
+#define GET
+#define GET_COMPL
+#endif
+
+#if ENABLE_FEATURE_TFTP_PUT
+#define PUT "p"
+#define PUT_COMPL ":p"
+#else
+#define PUT
+#define PUT_COMPL
+#endif
+
+#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
+
+ cmd = getopt32(argc, argv, GET PUT "l:r:" BS, &localfile, &remotefile BS_ARG);
+
+ cmd &= (tftp_cmd_get | tftp_cmd_put);
+#if ENABLE_FEATURE_TFTP_GET
+ if (cmd == tftp_cmd_get)
+ flags = O_WRONLY | O_CREAT | O_TRUNC;
+#endif
+#if ENABLE_FEATURE_TFTP_PUT
+ if (cmd == tftp_cmd_put)
+ flags = O_RDONLY;
+#endif
+
+#if ENABLE_FEATURE_TFTP_BLOCKSIZE
+ if (sblocksize) {
+ blocksize = xatoi_u(sblocksize);
+ if (!tftp_blocksize_check(blocksize, 0)) {
+ return EXIT_FAILURE;
+ }
+ }
+#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;
+ } else {
+ fd = open(localfile, flags, 0644); /* fail below */
+ }
+ if (fd < 0) {
+ bb_perror_msg_and_die("local file");
+ }
+
+ host = xgethostbyname(argv[optind]);
+ port = bb_lookup_port(argv[optind + 1], "udp", 69);
+
+#if ENABLE_DEBUG_TFTP
+ fprintf(stderr, "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);
+
+ 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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-17 13:22:44 +0300