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Clarified packet ownership transfer between a few functions. 

Added a large number of missing calls to free_pkb().  In the case of UDP,
no received packets were ever freed, which lead to memory exhaustion
remarkably quickly once pxelinux started up.

In general, any function with _rx() in its name which accepts a pk_buff
*must* either call free_pkb() or pass the pkb to another _rx() function
(e.g. the next layer up the stack).  Since the UDP (and TCP) layers don't
pass packet buffers up to the higher-layer protocols (the
"applications"), they must free the packet buffer after calling the
application's newdata() method.
This commit is contained in:
Michael Brown 2006-08-09 01:24:32 +00:00
parent fd07f56f0d
commit a3d508b648
6 changed files with 63 additions and 31 deletions
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10
src/include/gpxe/netdevice.h
View File

@ -83,6 +83,7 @@ struct ll_protocol {
*
* This method should prepend in the link-layer header
* (e.g. the Ethernet DIX header) and transmit the packet.
* This method takes ownership of the packet buffer.
*/
int ( * tx ) ( struct pk_buff *pkb, struct net_device *netdev,
struct net_protocol *net_protocol,
@ -95,9 +96,10 @@ struct ll_protocol {
*
* This method should strip off the link-layer header
* (e.g. the Ethernet DIX header) and pass the packet to
* net_rx().
* net_rx(). This method takes ownership of the packet
* buffer.
*/
void ( * rx ) ( struct pk_buff *pkb, struct net_device *netdev );
int ( * rx ) ( struct pk_buff *pkb, struct net_device *netdev );
/**
* Transcribe link-layer address
*
@ -206,8 +208,8 @@ extern int netdev_tx ( struct net_device *netdev, struct pk_buff *pkb );
extern void netdev_rx ( struct net_device *netdev, struct pk_buff *pkb );
extern int net_tx ( struct pk_buff *pkb, struct net_device *netdev,
struct net_protocol *net_protocol, const void *ll_dest );
extern void net_rx ( struct pk_buff *pkb, struct net_device *netdev,
uint16_t net_proto, const void *ll_source );
extern int net_rx ( struct pk_buff *pkb, struct net_device *netdev,
uint16_t net_proto, const void *ll_source );
extern int netdev_poll ( struct net_device *netdev );
extern struct pk_buff * netdev_rx_dequeue ( struct net_device *netdev );
extern struct net_device * alloc_netdev ( size_t priv_size );

8
src/net/ethernet.c
View File

@ -19,6 +19,7 @@
#include <stdint.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <assert.h>
#include <vsprintf.h>
#include <gpxe/if_arp.h>
@ -68,21 +69,22 @@ static int eth_tx ( struct pk_buff *pkb, struct net_device *netdev,
* Strips off the Ethernet link-layer header and passes up to the
* network-layer protocol.
*/
static void eth_rx ( struct pk_buff *pkb, struct net_device *netdev ) {
static int eth_rx ( struct pk_buff *pkb, struct net_device *netdev ) {
struct ethhdr *ethhdr = pkb->data;
/* Sanity check */
if ( pkb_len ( pkb ) < sizeof ( *ethhdr ) ) {
DBG ( "Ethernet packet too short (%d bytes)\n",
pkb_len ( pkb ) );
return;
free_pkb ( pkb );
return -EINVAL;
}
/* Strip off Ethernet header */
pkb_pull ( pkb, sizeof ( *ethhdr ) );
/* Hand off to network-layer protocol */
net_rx ( pkb, netdev, ethhdr->h_protocol, ethhdr->h_source );
return net_rx ( pkb, netdev, ethhdr->h_protocol, ethhdr->h_source );
}
/**

13
src/net/ipv4.c
View File

@ -389,9 +389,8 @@ static int ipv4_rx ( struct pk_buff *pkb, struct net_device *netdev __unused,
/* Sanity check */
if ( pkb_len ( pkb ) < sizeof ( *iphdr ) ) {
DBG ( "IP datagram too short (%d bytes)\n",
pkb_len ( pkb ) );
return -EINVAL;
DBG ( "IP datagram too short (%d bytes)\n", pkb_len ( pkb ) );
goto err;
}
/* Print IP4 header for debugging */
@ -400,14 +399,14 @@ static int ipv4_rx ( struct pk_buff *pkb, struct net_device *netdev __unused,
/* Validate version and header length */
if ( iphdr->verhdrlen != 0x45 ) {
DBG ( "Bad version and header length %x\n", iphdr->verhdrlen );
return -EINVAL;
goto err;
}
/* Validate length of IP packet */
if ( ntohs ( iphdr->len ) > pkb_len ( pkb ) ) {
DBG ( "Inconsistent packet length %d\n",
ntohs ( iphdr->len ) );
return -EINVAL;
goto err;
}
/* Verify the checksum */
@ -447,6 +446,10 @@ static int ipv4_rx ( struct pk_buff *pkb, struct net_device *netdev __unused,
/* Send it to the transport layer */
return tcpip_rx ( pkb, iphdr->protocol, &src.st, &dest.st );
err:
free_pkb ( pkb );
return -EINVAL;
}
/**

8
src/net/netdevice.c
View File

@ -97,8 +97,9 @@ int net_tx ( struct pk_buff *pkb, struct net_device *netdev,
* @v netdev Network device
* @v net_proto Network-layer protocol, in network-byte order
* @v ll_source Source link-layer address
* @ret rc Return status code
*/
void net_rx ( struct pk_buff *pkb, struct net_device *netdev,
int net_rx ( struct pk_buff *pkb, struct net_device *netdev,
uint16_t net_proto, const void *ll_source ) {
struct net_protocol *net_protocol;
@ -106,10 +107,11 @@ void net_rx ( struct pk_buff *pkb, struct net_device *netdev,
for ( net_protocol = net_protocols ; net_protocol < net_protocols_end ;
net_protocol++ ) {
if ( net_protocol->net_proto == net_proto ) {
net_protocol->rx ( pkb, netdev, ll_source );
break;
return net_protocol->rx ( pkb, netdev, ll_source );
}
}
free_pkb ( pkb );
return 0;
}
/**

2
src/net/tcpip.c
View File

@ -54,6 +54,7 @@ int tcpip_rx ( struct pk_buff *pkb, uint8_t tcpip_proto,
}
DBG ( "Unrecognised TCP/IP protocol %d\n", tcpip_proto );
free_pkb ( pkb );
return -EPROTONOSUPPORT;
}
@ -78,6 +79,7 @@ int tcpip_tx ( struct pk_buff *pkb, struct tcpip_protocol *tcpip_protocol,
}
DBG ( "Unrecognised TCP/IP address family %d\n", st_dest->st_family );
free_pkb ( pkb );
return -EAFNOSUPPORT;
}

53
src/net/udp.c
View File

@ -93,6 +93,8 @@ void udp_close ( struct udp_connection *conn ) {
* callback. The callback may use the buffer space
*/
int udp_senddata ( struct udp_connection *conn ) {
int rc;
conn->tx_pkb = alloc_pkb ( UDP_MAX_TXPKB );
if ( conn->tx_pkb == NULL ) {
DBG ( "UDP %p cannot allocate packet buffer of length %d\n",
@ -100,8 +102,11 @@ int udp_senddata ( struct udp_connection *conn ) {
return -ENOMEM;
}
pkb_reserve ( conn->tx_pkb, UDP_MAX_HLEN );
return conn->udp_op->senddata ( conn, conn->tx_pkb->data,
pkb_available ( conn->tx_pkb ) );
rc = conn->udp_op->senddata ( conn, conn->tx_pkb->data,
pkb_available ( conn->tx_pkb ) );
if ( conn->tx_pkb )
free_pkb ( conn->tx_pkb );
return rc;
}
/**
@ -122,13 +127,20 @@ int udp_senddata ( struct udp_connection *conn ) {
int udp_sendto ( struct udp_connection *conn, struct sockaddr_tcpip *peer,
const void *data, size_t len ) {
struct udp_header *udphdr;
struct pk_buff *pkb;
/* Take ownership of packet buffer back from the
* udp_connection structure.
*/
pkb = conn->tx_pkb;
conn->tx_pkb = NULL;
/* Avoid overflowing TX buffer */
if ( len > pkb_available ( conn->tx_pkb ) )
len = pkb_available ( conn->tx_pkb );
if ( len > pkb_available ( pkb ) )
len = pkb_available ( pkb );
/* Copy payload */
memmove ( pkb_put ( conn->tx_pkb, len ), data, len );
memmove ( pkb_put ( pkb, len ), data, len );
/*
* Add the UDP header
@ -136,22 +148,22 @@ int udp_sendto ( struct udp_connection *conn, struct sockaddr_tcpip *peer,
* Covert all 16- and 32- bit integers into network btye order before
* sending it over the network
*/
udphdr = pkb_push ( conn->tx_pkb, sizeof ( *udphdr ) );
udphdr = pkb_push ( pkb, sizeof ( *udphdr ) );
udphdr->dest_port = peer->st_port;
udphdr->source_port = conn->local_port;
udphdr->len = htons ( pkb_len ( conn->tx_pkb ) );
udphdr->len = htons ( pkb_len ( pkb ) );
udphdr->chksum = 0;
udphdr->chksum = tcpip_chksum ( udphdr, sizeof ( *udphdr ) + len );
/* Dump debugging information */
DBG ( "UDP %p transmitting %p+%#zx len %#x src %d dest %d "
"chksum %#04x\n", conn, conn->tx_pkb->data,
pkb_len ( conn->tx_pkb ), ntohs ( udphdr->len ),
"chksum %#04x\n", conn, pkb->data,
pkb_len ( pkb ), ntohs ( udphdr->len ),
ntohs ( udphdr->source_port ), ntohs ( udphdr->dest_port ),
ntohs ( udphdr->chksum ) );
/* Send it to the next layer for processing */
return tcpip_tx ( conn->tx_pkb, &udp_protocol, peer );
return tcpip_tx ( pkb, &udp_protocol, peer );
}
/**
@ -186,12 +198,14 @@ static int udp_rx ( struct pk_buff *pkb, struct sockaddr_tcpip *st_src,
struct udp_connection *conn;
unsigned int ulen;
uint16_t chksum;
int rc;
/* Sanity check */
if ( pkb_len ( pkb ) < sizeof ( *udphdr ) ) {
DBG ( "UDP received underlength packet %p+%#zx\n",
pkb->data, pkb_len ( pkb ) );
return -EINVAL;
rc = -EINVAL;
goto done;
}
/* Dump debugging information */
@ -205,7 +219,8 @@ static int udp_rx ( struct pk_buff *pkb, struct sockaddr_tcpip *st_src,
if ( ulen > pkb_len ( pkb ) ) {
DBG ( "UDP received truncated packet %p+%#zx\n",
pkb->data, pkb_len ( pkb ) );
return -EINVAL;
rc = -EINVAL;
goto done;
}
pkb_unput ( pkb, ( pkb_len ( pkb ) - ulen ) );
@ -215,7 +230,8 @@ static int udp_rx ( struct pk_buff *pkb, struct sockaddr_tcpip *st_src,
chksum = tcpip_chksum ( pkb->data, pkb_len ( pkb ) );
if ( chksum != 0xffff ) {
DBG ( "Bad checksum %#x\n", chksum );
return -EINVAL;
rc = -EINVAL;
goto done;
}
#endif
@ -237,13 +253,18 @@ static int udp_rx ( struct pk_buff *pkb, struct sockaddr_tcpip *st_src,
DBG ( "UDP delivering to %p\n", conn );
/* Call the application's callback */
return conn->udp_op->newdata ( conn, pkb->data, pkb_len( pkb ),
st_src, st_dest );
rc = conn->udp_op->newdata ( conn, pkb->data, pkb_len( pkb ),
st_src, st_dest );
goto done;
}
DBG ( "No UDP connection listening on port %d\n",
ntohs ( udphdr->dest_port ) );
return 0;
rc = 0;
done:
free_pkb ( pkb );
return rc;
}
struct tcpip_protocol udp_protocol = {