Added basic write support to the Slirp TFTP server.
TODO #1: implement all features of the existing (vnet) TFTP support in Slirp. TODO #2: make the slirp DHCP server work like the vnet one. TODO #3: finally remove the slirp backend and rename the new one to "slirp".
This commit is contained in:
Volker Ruppert
parent
be368f54d1
commit
eb3f567f4a
@ -91,9 +91,9 @@ static int tftp_session_find(Slirp *slirp, struct tftp_t *tp)
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if (tftp_session_in_use(spt)) {
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if (!memcmp(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip))) {
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if (spt->client_port == tp->udp.uh_sport) {
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return k;
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}
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if (spt->client_port == tp->udp.uh_sport) {
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return k;
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}
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}
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}
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}
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@ -135,7 +135,7 @@ static int tftp_send_oack(struct tftp_session *spt,
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m = m_get(spt->slirp);
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if (!m)
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return -1;
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return -1;
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memset(m->m_data, 0, m->m_size);
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@ -164,6 +164,40 @@ static int tftp_send_oack(struct tftp_session *spt,
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return 0;
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}
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static int tftp_send_ack(struct tftp_session *spt,
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struct tftp_t *recv_tp)
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{
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struct sockaddr_in saddr, daddr;
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struct mbuf *m;
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struct tftp_t *tp;
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m = m_get(spt->slirp);
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if (!m)
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return -1;
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memset(m->m_data, 0, m->m_size);
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m->m_data += IF_MAXLINKHDR;
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tp = (tftp_t*)m->m_data;
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m->m_data += sizeof(struct udpiphdr);
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tp->tp_op = htons(TFTP_ACK);
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tp->x.tp_data.tp_block_nr = htons(spt->block_nr & 0xffff);
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saddr.sin_addr = recv_tp->ip.ip_dst;
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saddr.sin_port = recv_tp->udp.uh_dport;
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daddr.sin_addr = spt->client_ip;
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daddr.sin_port = spt->client_port;
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m->m_len = sizeof(struct tftp_t) - 514 + 2 -
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sizeof(struct ip) - sizeof(struct udphdr);
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udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
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return 0;
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}
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static void tftp_send_error(struct tftp_session *spt,
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uint16_t errorcode, const char *msg,
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struct tftp_t *recv_tp)
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@ -282,6 +316,7 @@ static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
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}
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spt = &slirp->tftp_sessions[s];
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spt->write = 0;
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/* unspecifed prefix means service disabled */
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if (!slirp->tftp_prefix) {
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@ -352,25 +387,25 @@ static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
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k += strlen(key) + 1;
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if (k >= pktlen) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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value = &tp->x.tp_buf[k];
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k += strlen(value) + 1;
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if (strcasecmp(key, "tsize") == 0) {
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int tsize = atoi(value);
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struct stat stat_p;
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int tsize = atoi(value);
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struct stat stat_p;
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if (tsize == 0) {
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if (stat(spt->filename, &stat_p) == 0)
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tsize = stat_p.st_size;
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else {
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tftp_send_error(spt, 1, "File not found", tp);
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return;
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}
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}
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if (tsize == 0) {
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if (stat(spt->filename, &stat_p) == 0)
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tsize = stat_p.st_size;
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else {
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tftp_send_error(spt, 1, "File not found", tp);
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return;
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}
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}
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option_name[nb_options] = "tsize";
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option_value[nb_options] = tsize;
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@ -400,6 +435,191 @@ static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
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tftp_send_next_block(spt, tp);
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}
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static void tftp_handle_wrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
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{
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struct tftp_session *spt;
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int s, k, fd;
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size_t prefix_len;
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char *req_fname;
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const char *option_name[2];
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uint32_t option_value[2];
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unsigned nb_options = 0;
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/* check if a session already exists and if so terminate it */
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s = tftp_session_find(slirp, tp);
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if (s >= 0) {
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tftp_session_terminate(&slirp->tftp_sessions[s]);
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}
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s = tftp_session_allocate(slirp, tp);
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if (s < 0) {
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return;
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}
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spt = &slirp->tftp_sessions[s];
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spt->write = 1;
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/* unspecifed prefix means service disabled */
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if (!slirp->tftp_prefix) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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/* skip header fields */
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k = 0;
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pktlen -= offsetof(struct tftp_t, x.tp_buf);
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/* prepend tftp_prefix */
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prefix_len = strlen(slirp->tftp_prefix);
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spt->filename = (char*)malloc(prefix_len + TFTP_FILENAME_MAX + 2);
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memcpy(spt->filename, slirp->tftp_prefix, prefix_len);
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spt->filename[prefix_len] = '/';
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/* get name */
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req_fname = spt->filename + prefix_len + 1;
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while (1) {
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if (k >= TFTP_FILENAME_MAX || k >= pktlen) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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req_fname[k] = tp->x.tp_buf[k];
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if (req_fname[k++] == '\0') {
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break;
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}
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}
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/* check mode */
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if ((pktlen - k) < 6) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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if (strcasecmp(&tp->x.tp_buf[k], "octet") != 0) {
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tftp_send_error(spt, 4, "Unsupported transfer mode", tp);
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return;
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}
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k += 6; /* skipping octet */
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/* do sanity checks on the filename */
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if (!strncmp(req_fname, "../", 3) ||
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req_fname[strlen(req_fname) - 1] == '/' ||
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strstr(req_fname, "/../")) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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/* check if the file exists */
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fd = open(spt->filename, O_RDONLY | O_BINARY);
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if (fd >= 0) {
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close(fd);
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tftp_send_error(spt, 6, "File exists", tp);
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return;
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}
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/* create new file */
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spt->fd = open(spt->filename, O_CREAT | O_WRONLY
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#ifdef O_BINARY
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| O_BINARY
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#endif
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, S_IWUSR | S_IRUSR | S_IRGRP | S_IWGRP);
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if (spt->fd < 0) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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if (tp->x.tp_buf[pktlen - 1] != 0) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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while (k < pktlen && nb_options < ARRAY_SIZE(option_name)) {
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const char *key, *value;
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key = &tp->x.tp_buf[k];
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k += strlen(key) + 1;
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if (k >= pktlen) {
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tftp_send_error(spt, 2, "Access violation", tp);
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return;
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}
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value = &tp->x.tp_buf[k];
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k += strlen(value) + 1;
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if (strcasecmp(key, "tsize") == 0) {
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int tsize = atoi(value);
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struct stat stat_p;
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if (tsize == 0) {
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if (stat(spt->filename, &stat_p) == 0)
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tsize = stat_p.st_size;
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else {
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tftp_send_error(spt, 1, "File not found", tp);
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return;
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}
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}
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option_name[nb_options] = "tsize";
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option_value[nb_options] = tsize;
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nb_options++;
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} else if (strcasecmp(key, "blksize") == 0) {
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int blksize = atoi(value);
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/* If blksize option is bigger than what we will
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* emit, accept the option with our packet size.
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* Otherwise, simply do as we didn't see the option.
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*/
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if (blksize >= 512) {
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option_name[nb_options] = "blksize";
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option_value[nb_options] = 512;
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nb_options++;
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}
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}
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}
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spt->block_nr = 0;
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if (nb_options > 0) {
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assert(nb_options <= ARRAY_SIZE(option_name));
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tftp_send_oack(spt, option_name, option_value, nb_options, tp);
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} else {
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tftp_send_ack(spt, tp);
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}
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}
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static void tftp_handle_data(Slirp *slirp, struct tftp_t *tp, int pktlen)
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{
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struct tftp_session *spt;
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int s, nobytes;
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s = tftp_session_find(slirp, tp);
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if (s < 0) {
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return;
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}
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spt = &slirp->tftp_sessions[s];
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if (spt->write == 1) {
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spt->block_nr = ntohs(tp->x.tp_data.tp_block_nr);
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nobytes = pktlen - offsetof(struct tftp_t, x.tp_data.tp_buf);
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if (nobytes <= 512) {
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lseek(spt->fd, (spt->block_nr - 1) * 512, SEEK_SET);
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write(spt->fd, tp->x.tp_data.tp_buf, nobytes);
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tftp_send_ack(spt, tp);
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if (nobytes == 512) {
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tftp_session_update(spt);
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} else {
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tftp_session_terminate(spt);
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}
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} else {
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tftp_send_error(spt, 2, "Access violation", tp);
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}
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} else {
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tftp_send_error(spt, 2, "Access violation", tp);
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}
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}
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static void tftp_handle_ack(Slirp *slirp, struct tftp_t *tp, int pktlen)
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{
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int s;
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@ -430,18 +650,26 @@ void tftp_input(struct mbuf *m)
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{
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struct tftp_t *tp = (struct tftp_t *)m->m_data;
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switch(ntohs(tp->tp_op)) {
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case TFTP_RRQ:
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tftp_handle_rrq(m->slirp, tp, m->m_len);
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break;
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switch (ntohs(tp->tp_op)) {
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case TFTP_RRQ:
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tftp_handle_rrq(m->slirp, tp, m->m_len);
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break;
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case TFTP_ACK:
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tftp_handle_ack(m->slirp, tp, m->m_len);
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break;
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case TFTP_WRQ:
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tftp_handle_wrq(m->slirp, tp, m->m_len);
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break;
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case TFTP_ERROR:
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tftp_handle_error(m->slirp, tp, m->m_len);
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break;
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case TFTP_DATA:
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tftp_handle_data(m->slirp, tp, m->m_len);
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break;
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case TFTP_ACK:
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tftp_handle_ack(m->slirp, tp, m->m_len);
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break;
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case TFTP_ERROR:
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tftp_handle_error(m->slirp, tp, m->m_len);
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break;
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}
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}
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@ -44,6 +44,7 @@ struct tftp_session {
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struct in_addr client_ip;
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uint16_t client_port;
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uint32_t block_nr;
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bx_bool write;
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int timestamp;
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};
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