/*
* tftp.c - a simple, read-only tftp server for qemu
- *
+ *
* Copyright (c) 2004 Magnus Damm <damm@opensource.se>
- *
+ *
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
*/
#include <slirp.h>
+#include "qemu-common.h"
-struct tftp_session {
- int in_use;
- unsigned char filename[TFTP_FILENAME_MAX];
-
- struct in_addr client_ip;
- u_int16_t client_port;
-
- int timestamp;
-};
-
-struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
-
-char *tftp_prefix;
+static inline int tftp_session_in_use(struct tftp_session *spt)
+{
+ return (spt->slirp != NULL);
+}
-static void tftp_session_update(struct tftp_session *spt)
+static inline void tftp_session_update(struct tftp_session *spt)
{
spt->timestamp = curtime;
- spt->in_use = 1;
}
static void tftp_session_terminate(struct tftp_session *spt)
{
- spt->in_use = 0;
+ if (spt->fd >= 0) {
+ close(spt->fd);
+ spt->fd = -1;
+ }
+ g_free(spt->filename);
+ spt->slirp = NULL;
}
-static int tftp_session_allocate(struct tftp_t *tp)
+static int tftp_session_allocate(Slirp *slirp, struct tftp_t *tp)
{
struct tftp_session *spt;
int k;
for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
- spt = &tftp_sessions[k];
+ spt = &slirp->tftp_sessions[k];
- if (!spt->in_use)
+ if (!tftp_session_in_use(spt))
goto found;
/* sessions time out after 5 inactive seconds */
- if ((int)(curtime - spt->timestamp) > 5000)
+ if ((int)(curtime - spt->timestamp) > 5000) {
+ tftp_session_terminate(spt);
goto found;
+ }
}
return -1;
found:
memset(spt, 0, sizeof(*spt));
memcpy(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip));
+ spt->fd = -1;
spt->client_port = tp->udp.uh_sport;
+ spt->slirp = slirp;
tftp_session_update(spt);
return k;
}
-static int tftp_session_find(struct tftp_t *tp)
+static int tftp_session_find(Slirp *slirp, struct tftp_t *tp)
{
struct tftp_session *spt;
int k;
for (k = 0; k < TFTP_SESSIONS_MAX; k++) {
- spt = &tftp_sessions[k];
+ spt = &slirp->tftp_sessions[k];
- if (spt->in_use) {
+ if (tftp_session_in_use(spt)) {
if (!memcmp(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip))) {
if (spt->client_port == tp->udp.uh_sport) {
return k;
return -1;
}
-static int tftp_read_data(struct tftp_session *spt, u_int16_t block_nr,
- u_int8_t *buf, int len)
+static int tftp_read_data(struct tftp_session *spt, uint32_t block_nr,
+ uint8_t *buf, int len)
{
- int fd;
- int bytes_read = 0;
+ int bytes_read = 0;
+
+ if (spt->fd < 0) {
+ spt->fd = open(spt->filename, O_RDONLY | O_BINARY);
+ }
- fd = open(spt->filename, O_RDONLY);
+ if (spt->fd < 0) {
+ return -1;
+ }
- if (fd < 0) {
- return -1;
- }
+ if (len) {
+ lseek(spt->fd, block_nr * 512, SEEK_SET);
- if (len) {
- lseek(fd, block_nr * 512, SEEK_SET);
+ bytes_read = read(spt->fd, buf, len);
+ }
- bytes_read = read(fd, buf, len);
- }
+ return bytes_read;
+}
+
+static int tftp_send_oack(struct tftp_session *spt,
+ const char *keys[], uint32_t values[], int nb,
+ struct tftp_t *recv_tp)
+{
+ struct sockaddr_in saddr, daddr;
+ struct mbuf *m;
+ struct tftp_t *tp;
+ int i, n = 0;
+
+ m = m_get(spt->slirp);
- close(fd);
+ if (!m)
+ return -1;
- return bytes_read;
+ memset(m->m_data, 0, m->m_size);
+
+ m->m_data += IF_MAXLINKHDR;
+ tp = (void *)m->m_data;
+ m->m_data += sizeof(struct udpiphdr);
+
+ tp->tp_op = htons(TFTP_OACK);
+ for (i = 0; i < nb; i++) {
+ n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s",
+ keys[i]) + 1;
+ n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u",
+ values[i]) + 1;
+ }
+
+ saddr.sin_addr = recv_tp->ip.ip_dst;
+ saddr.sin_port = recv_tp->udp.uh_dport;
+
+ daddr.sin_addr = spt->client_ip;
+ daddr.sin_port = spt->client_port;
+
+ m->m_len = sizeof(struct tftp_t) - 514 + n -
+ sizeof(struct ip) - sizeof(struct udphdr);
+ udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
+
+ return 0;
}
-static int tftp_send_error(struct tftp_session *spt,
- u_int16_t errorcode, const char *msg,
- struct tftp_t *recv_tp)
+static void tftp_send_error(struct tftp_session *spt,
+ uint16_t errorcode, const char *msg,
+ struct tftp_t *recv_tp)
{
struct sockaddr_in saddr, daddr;
struct mbuf *m;
struct tftp_t *tp;
- int nobytes;
- m = m_get();
+ m = m_get(spt->slirp);
if (!m) {
- return -1;
+ goto out;
}
memset(m->m_data, 0, m->m_size);
- m->m_data += if_maxlinkhdr;
+ m->m_data += IF_MAXLINKHDR;
tp = (void *)m->m_data;
m->m_data += sizeof(struct udpiphdr);
-
+
tp->tp_op = htons(TFTP_ERROR);
tp->x.tp_error.tp_error_code = htons(errorcode);
- strcpy(tp->x.tp_error.tp_msg, msg);
+ pstrcpy((char *)tp->x.tp_error.tp_msg, sizeof(tp->x.tp_error.tp_msg), msg);
saddr.sin_addr = recv_tp->ip.ip_dst;
saddr.sin_port = recv_tp->udp.uh_dport;
daddr.sin_addr = spt->client_ip;
daddr.sin_port = spt->client_port;
- nobytes = 2;
-
- m->m_len = sizeof(struct tftp_t) - 514 + 3 + strlen(msg) -
+ m->m_len = sizeof(struct tftp_t) - 514 + 3 + strlen(msg) -
sizeof(struct ip) - sizeof(struct udphdr);
udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
+out:
tftp_session_terminate(spt);
-
- return 0;
}
-static int tftp_send_data(struct tftp_session *spt,
- u_int16_t block_nr,
- struct tftp_t *recv_tp)
+static void tftp_send_next_block(struct tftp_session *spt,
+ struct tftp_t *recv_tp)
{
struct sockaddr_in saddr, daddr;
struct mbuf *m;
struct tftp_t *tp;
int nobytes;
- if (block_nr < 1) {
- return -1;
- }
-
- m = m_get();
+ m = m_get(spt->slirp);
if (!m) {
- return -1;
+ return;
}
memset(m->m_data, 0, m->m_size);
- m->m_data += if_maxlinkhdr;
+ m->m_data += IF_MAXLINKHDR;
tp = (void *)m->m_data;
m->m_data += sizeof(struct udpiphdr);
-
+
tp->tp_op = htons(TFTP_DATA);
- tp->x.tp_data.tp_block_nr = htons(block_nr);
+ tp->x.tp_data.tp_block_nr = htons((spt->block_nr + 1) & 0xffff);
saddr.sin_addr = recv_tp->ip.ip_dst;
saddr.sin_port = recv_tp->udp.uh_dport;
daddr.sin_addr = spt->client_ip;
daddr.sin_port = spt->client_port;
- nobytes = tftp_read_data(spt, block_nr - 1, tp->x.tp_data.tp_buf, 512);
+ nobytes = tftp_read_data(spt, spt->block_nr, tp->x.tp_data.tp_buf, 512);
if (nobytes < 0) {
m_free(m);
tftp_send_error(spt, 1, "File not found", tp);
- return -1;
+ return;
}
- m->m_len = sizeof(struct tftp_t) - (512 - nobytes) -
+ m->m_len = sizeof(struct tftp_t) - (512 - nobytes) -
sizeof(struct ip) - sizeof(struct udphdr);
udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
tftp_session_terminate(spt);
}
- return 0;
+ spt->block_nr++;
}
-static void tftp_handle_rrq(struct tftp_t *tp, int pktlen)
+static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
{
struct tftp_session *spt;
- int s, k, n;
- u_int8_t *src, *dst;
+ int s, k;
+ size_t prefix_len;
+ char *req_fname;
+ const char *option_name[2];
+ uint32_t option_value[2];
+ int nb_options = 0;
+
+ /* check if a session already exists and if so terminate it */
+ s = tftp_session_find(slirp, tp);
+ if (s >= 0) {
+ tftp_session_terminate(&slirp->tftp_sessions[s]);
+ }
- s = tftp_session_allocate(tp);
+ s = tftp_session_allocate(slirp, tp);
if (s < 0) {
return;
}
- spt = &tftp_sessions[s];
+ spt = &slirp->tftp_sessions[s];
- src = tp->x.tp_buf;
- dst = spt->filename;
- n = pktlen - ((uint8_t *)&tp->x.tp_buf[0] - (uint8_t *)tp);
+ /* unspecifed prefix means service disabled */
+ if (!slirp->tftp_prefix) {
+ tftp_send_error(spt, 2, "Access violation", tp);
+ return;
+ }
+
+ /* skip header fields */
+ k = 0;
+ pktlen -= offsetof(struct tftp_t, x.tp_buf);
+
+ /* prepend tftp_prefix */
+ prefix_len = strlen(slirp->tftp_prefix);
+ spt->filename = g_malloc(prefix_len + TFTP_FILENAME_MAX + 2);
+ memcpy(spt->filename, slirp->tftp_prefix, prefix_len);
+ spt->filename[prefix_len] = '/';
/* get name */
+ req_fname = spt->filename + prefix_len + 1;
- for (k = 0; k < n; k++) {
- if (k < TFTP_FILENAME_MAX) {
- dst[k] = src[k];
- }
- else {
+ while (1) {
+ if (k >= TFTP_FILENAME_MAX || k >= pktlen) {
+ tftp_send_error(spt, 2, "Access violation", tp);
return;
}
-
- if (src[k] == '\0') {
+ req_fname[k] = tp->x.tp_buf[k];
+ if (req_fname[k++] == '\0') {
break;
}
}
-
- if (k >= n) {
- return;
- }
-
- k++;
-
+
/* check mode */
- if ((n - k) < 6) {
+ if ((pktlen - k) < 6) {
+ tftp_send_error(spt, 2, "Access violation", tp);
return;
}
-
- if (memcmp(&src[k], "octet\0", 6) != 0) {
+
+ if (strcasecmp(&tp->x.tp_buf[k], "octet") != 0) {
tftp_send_error(spt, 4, "Unsupported transfer mode", tp);
return;
}
- /* do sanity checks on the filename */
+ k += 6; /* skipping octet */
- if ((spt->filename[0] != '/')
- || (spt->filename[strlen(spt->filename) - 1] == '/')
- || strstr(spt->filename, "/../")) {
+ /* do sanity checks on the filename */
+ if (!strncmp(req_fname, "../", 3) ||
+ req_fname[strlen(req_fname) - 1] == '/' ||
+ strstr(req_fname, "/../")) {
tftp_send_error(spt, 2, "Access violation", tp);
return;
}
- /* only allow exported prefixes */
+ /* check if the file exists */
+ if (tftp_read_data(spt, 0, NULL, 0) < 0) {
+ tftp_send_error(spt, 1, "File not found", tp);
+ return;
+ }
- if (!tftp_prefix
- || (strncmp(spt->filename, tftp_prefix, strlen(tftp_prefix)) != 0)) {
+ if (tp->x.tp_buf[pktlen - 1] != 0) {
tftp_send_error(spt, 2, "Access violation", tp);
return;
}
- /* check if the file exists */
-
- if (tftp_read_data(spt, 0, spt->filename, 0) < 0) {
- tftp_send_error(spt, 1, "File not found", tp);
+ while (k < pktlen && nb_options < ARRAY_SIZE(option_name)) {
+ const char *key, *value;
+
+ key = &tp->x.tp_buf[k];
+ k += strlen(key) + 1;
+
+ if (k >= pktlen) {
+ tftp_send_error(spt, 2, "Access violation", tp);
+ return;
+ }
+
+ value = &tp->x.tp_buf[k];
+ k += strlen(value) + 1;
+
+ if (strcasecmp(key, "tsize") == 0) {
+ int tsize = atoi(value);
+ struct stat stat_p;
+
+ if (tsize == 0) {
+ if (stat(spt->filename, &stat_p) == 0)
+ tsize = stat_p.st_size;
+ else {
+ tftp_send_error(spt, 1, "File not found", tp);
+ return;
+ }
+ }
+
+ option_name[nb_options] = "tsize";
+ option_value[nb_options] = tsize;
+ nb_options++;
+ } else if (strcasecmp(key, "blksize") == 0) {
+ int blksize = atoi(value);
+
+ /* If blksize option is bigger than what we will
+ * emit, accept the option with our packet size.
+ * Otherwise, simply do as we didn't see the option.
+ */
+ if (blksize >= 512) {
+ option_name[nb_options] = "blksize";
+ option_value[nb_options] = 512;
+ nb_options++;
+ }
+ }
+ }
+
+ if (nb_options > 0) {
+ assert(nb_options <= ARRAY_SIZE(option_name));
+ tftp_send_oack(spt, option_name, option_value, nb_options, tp);
return;
}
- tftp_send_data(spt, 1, tp);
+ spt->block_nr = 0;
+ tftp_send_next_block(spt, tp);
}
-static void tftp_handle_ack(struct tftp_t *tp, int pktlen)
+static void tftp_handle_ack(Slirp *slirp, struct tftp_t *tp, int pktlen)
{
int s;
- s = tftp_session_find(tp);
+ s = tftp_session_find(slirp, tp);
if (s < 0) {
return;
}
- if (tftp_send_data(&tftp_sessions[s],
- ntohs(tp->x.tp_data.tp_block_nr) + 1,
- tp) < 0) {
+ tftp_send_next_block(&slirp->tftp_sessions[s], tp);
+}
+
+static void tftp_handle_error(Slirp *slirp, struct tftp_t *tp, int pktlen)
+{
+ int s;
+
+ s = tftp_session_find(slirp, tp);
+
+ if (s < 0) {
return;
}
+
+ tftp_session_terminate(&slirp->tftp_sessions[s]);
}
void tftp_input(struct mbuf *m)
switch(ntohs(tp->tp_op)) {
case TFTP_RRQ:
- tftp_handle_rrq(tp, m->m_len);
+ tftp_handle_rrq(m->slirp, tp, m->m_len);
break;
case TFTP_ACK:
- tftp_handle_ack(tp, m->m_len);
+ tftp_handle_ack(m->slirp, tp, m->m_len);
+ break;
+
+ case TFTP_ERROR:
+ tftp_handle_error(m->slirp, tp, m->m_len);
break;
}
}
projects / qemu.git / blobdiff