tftp: fix wrong check for port numbers
diff --git a/include/libbb.h b/include/libbb.h
index 8ad9226..8f3d7f0 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -290,7 +290,7 @@
/* "new" (ipv4+ipv6) API */
typedef struct len_and_sockaddr {
- int len;
+ socklen_t len;
union {
struct sockaddr sa;
struct sockaddr_in sin;
diff --git a/networking/tftp.c b/networking/tftp.c
index eb192d8..bafcddb 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -132,7 +132,7 @@
#if ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
const int cmd,
#endif
- const len_and_sockaddr *peer_lsa,
+ len_and_sockaddr *peer_lsa,
const char *remotefile, const int localfd,
unsigned port, int tftp_bufsize)
{
@@ -149,6 +149,9 @@
USE_FEATURE_TFTP_BLOCKSIZE(int want_option_ack = 0;)
+ unsigned org_port;
+ len_and_sockaddr *const from = alloca(offsetof(len_and_sockaddr, sa) + peer_lsa->len);
+
/* Can't use RESERVE_CONFIG_BUFFER here since the allocation
* size varies meaning BUFFERS_GO_ON_STACK would fail */
/* We must keep the transmit and receive buffers seperate */
@@ -156,7 +159,7 @@
char *xbuf = xmalloc(tftp_bufsize += 4);
char *rbuf = xmalloc(tftp_bufsize);
- port = htons(port);
+ port = org_port = htons(port);
socketfd = xsocket(peer_lsa->sa.sa_family, SOCK_DGRAM, 0);
@@ -167,10 +170,10 @@
}
while (1) {
-
cp = xbuf;
/* first create the opcode part */
+ /* (this 16bit store is aligned) */
*((uint16_t*)cp) = htons(opcode);
cp += 2;
@@ -222,6 +225,7 @@
/* add ack and data */
if (CMD_GET(cmd) ? (opcode == TFTP_ACK) : (opcode == TFTP_DATA)) {
+ /* TODO: unaligned access! */
*((uint16_t*)cp) = htons(block_nr);
cp += 2;
block_nr++;
@@ -273,28 +277,26 @@
FD_SET(socketfd, &rfds);
switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) {
- struct sockaddr *from;
- socklen_t fromlen;
-
+ unsigned from_port;
case 1:
- fromlen = peer_lsa->len;
- from = alloca(fromlen);
- memset(from, 0, fromlen);
-
+ from->len = peer_lsa->len;
+ memset(&from->sa, 0, peer_lsa->len);
len = recvfrom(socketfd, rbuf, tftp_bufsize, 0,
- from, &fromlen);
+ &from->sa, &from->len);
if (len < 0) {
bb_perror_msg("recvfrom");
break;
}
-#if ENABLE_FEATURE_IPV6
- if (from->sa_family == AF_INET6)
- if (((struct sockaddr_in6*)from)->sin6_port != port)
- goto recv_again;
-#endif
- if (from->sa_family == AF_INET)
- if (((struct sockaddr_in*)from)->sin_port != port)
- goto recv_again;
+ from_port = get_nport(from);
+ if (port == org_port) {
+ /* Our first query went to port 69
+ * but reply will come from different one.
+ * Remember and use this new port */
+ port = from_port;
+ set_nport(peer_lsa, from_port);
+ }
+ if (port != from_port)
+ goto recv_again;
timeout = 0;
break;
case 0:
@@ -317,6 +319,7 @@
}
/* process received packet */
+ /* (both accesses seems to be aligned) */
opcode = ntohs( ((uint16_t*)rbuf)[0] );
tmp = ntohs( ((uint16_t*)rbuf)[1] );
