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[udp] Verify local socket address (if specified) for UDP sockets

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UDP sockets can be used for multicast, at which point it becomes
plausible that we could receive packets that aren't destined for us
but that still match on a port number.
This commit is contained in:
Michael Brown 2008-06-09 22:56:48 +01:00
parent 77a5cc6b13
commit aa160211c2
2 changed files with 38 additions and 22 deletions
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9
src/include/gpxe/in.h
View File

@ -62,6 +62,15 @@ struct sockaddr_in {
uint16_t sin_port;
/** IPv4 address */
struct in_addr sin_addr;
/** Padding
*
* This ensures that a struct @c sockaddr_tcpip is large
* enough to hold a socket address for any TCP/IP address
* family.
*/
char pad[ sizeof ( struct sockaddr ) - sizeof ( sa_family_t )
- sizeof ( uint16_t )
- sizeof ( struct in_addr ) ];
};
/**

51
src/net/udp.c
View File

@ -29,10 +29,10 @@ struct udp_connection {
/** Data transfer interface */
struct xfer_interface xfer;
/** Local socket address */
struct sockaddr_tcpip local;
/** Remote socket address */
struct sockaddr_tcpip peer;
/** Local port on which the connection receives packets */
unsigned int local_port;
};
/**
@ -48,22 +48,22 @@ struct tcpip_protocol udp_protocol;
* Bind UDP connection to local port
*
* @v udp UDP connection
* @v port Local port, in network byte order, or zero
* @ret rc Return status code
*
* Opens the UDP connection and binds to a local port. If no local
* port is specified, the first available port will be used.
* Opens the UDP connection and binds to the specified local port. If
* no local port is specified, the first available port will be used.
*/
static int udp_bind ( struct udp_connection *udp, unsigned int port ) {
static int udp_bind ( struct udp_connection *udp ) {
struct udp_connection *existing;
static uint16_t try_port = 1024;
/* If no port specified, find the first available port */
if ( ! port ) {
if ( ! udp->local.st_port ) {
for ( ; try_port ; try_port++ ) {
if ( try_port < 1024 )
continue;
if ( udp_bind ( udp, htons ( try_port ) ) == 0 )
udp->local.st_port = htons ( try_port );
if ( udp_bind ( udp ) == 0 )
return 0;
}
return -EADDRINUSE;
@ -71,16 +71,16 @@ static int udp_bind ( struct udp_connection *udp, unsigned int port ) {
/* Attempt bind to local port */
list_for_each_entry ( existing, &udp_conns, list ) {
if ( existing->local_port == port ) {
if ( existing->local.st_port == udp->local.st_port ) {
DBGC ( udp, "UDP %p could not bind: port %d in use\n",
udp, ntohs ( port ) );
udp, ntohs ( udp->local.st_port ) );
return -EADDRINUSE;
}
}
udp->local_port = port;
/* Add to UDP connection list */
DBGC ( udp, "UDP %p bound to port %d\n", udp, ntohs ( port ) );
DBGC ( udp, "UDP %p bound to port %d\n",
udp, ntohs ( udp->local.st_port ) );
return 0;
}
@ -100,7 +100,6 @@ static int udp_open_common ( struct xfer_interface *xfer,
struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
struct udp_connection *udp;
unsigned int bind_port;
int rc;
/* Allocate and initialise structure */
@ -111,11 +110,12 @@ static int udp_open_common ( struct xfer_interface *xfer,
xfer_init ( &udp->xfer, &udp_xfer_operations, &udp->refcnt );
if ( st_peer )
memcpy ( &udp->peer, st_peer, sizeof ( udp->peer ) );
if ( st_local )
memcpy ( &udp->local, st_local, sizeof ( udp->local ) );
/* Bind to local port */
if ( ! promisc ) {
bind_port = ( st_local ? st_local->st_port : 0 );
if ( ( rc = udp_bind ( udp, bind_port ) ) != 0 )
if ( ( rc = udp_bind ( udp ) ) != 0 )
goto err;
}
@ -201,7 +201,7 @@ static int udp_tx ( struct udp_connection *udp, struct io_buffer *iobuf,
/* Fill in default values if not explicitly provided */
if ( ! src_port )
src_port = udp->local_port;
src_port = udp->local.st_port;
if ( ! dest )
dest = &udp->peer;
@ -231,17 +231,24 @@ static int udp_tx ( struct udp_connection *udp, struct io_buffer *iobuf,
}
/**
* Identify UDP connection by local port number
* Identify UDP connection by local address
*
* @v local_port Local port (in network-endian order)
* @v local Local address
* @ret udp UDP connection, or NULL
*/
static struct udp_connection * udp_demux ( unsigned int local_port ) {
static struct udp_connection * udp_demux ( struct sockaddr_tcpip *local ) {
static const struct sockaddr_tcpip empty_sockaddr;
struct udp_connection *udp;
list_for_each_entry ( udp, &udp_conns, list ) {
if ( ( udp->local_port == local_port ) ||
( udp->local_port == 0 ) ) {
if ( ( ( udp->local.st_family == local->st_family ) ||
( udp->local.st_family == 0 ) ) &&
( ( udp->local.st_port == local->st_port ) ||
( udp->local.st_port == 0 ) ) &&
( ( memcmp ( udp->local.pad, local->pad,
sizeof ( udp->local.pad ) ) == 0 ) ||
( memcmp ( udp->local.pad, empty_sockaddr.pad,
sizeof ( udp->local.pad ) ) == 0 ) ) ) {
return udp;
}
}
@ -300,7 +307,7 @@ static int udp_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src,
/* Parse parameters from header and strip header */
st_src->st_port = udphdr->src;
st_dest->st_port = udphdr->dest;
udp = udp_demux ( udphdr->dest );
udp = udp_demux ( st_dest );
iob_unput ( iobuf, ( iob_len ( iobuf ) - ulen ) );
iob_pull ( iobuf, sizeof ( *udphdr ) );