#include <ipxe/tcpip.h>
#include <ipxe/dhcp.h>
#include <ipxe/settings.h>
+#include <ipxe/timer.h>
/** @file
*
struct list_head ipv4_miniroutes = LIST_HEAD_INIT ( ipv4_miniroutes );
/** List of fragment reassembly buffers */
-static LIST_HEAD ( frag_buffers );
+static LIST_HEAD ( ipv4_fragments );
+
+/** Fragment reassembly timeout */
+#define IP_FRAG_TIMEOUT ( TICKS_PER_SEC / 2 )
/**
* Add IPv4 minirouting table entry
}
/**
- * Fragment reassembly counter timeout
+ * Expire fragment reassembly buffer
*
- * @v timer Retry timer
- * @v over If asserted, the timer is greater than @c MAX_TIMEOUT
+ * @v timer Retry timer
+ * @v fail Failure indicator
*/
-static void ipv4_frag_expired ( struct retry_timer *timer __unused,
- int over ) {
- if ( over ) {
- DBG ( "Fragment reassembly timeout" );
- /* Free the fragment buffer */
- }
+static void ipv4_fragment_expired ( struct retry_timer *timer,
+ int fail __unused ) {
+ struct ipv4_fragment *frag =
+ container_of ( timer, struct ipv4_fragment, timer );
+ struct iphdr *iphdr = frag->iobuf->data;
+
+ DBG ( "IPv4 fragment %04x expired\n", ntohs ( iphdr->ident ) );
+ free_iob ( frag->iobuf );
+ list_del ( &frag->list );
+ free ( frag );
}
/**
- * Free fragment buffer
+ * Find matching fragment reassembly buffer
*
- * @v fragbug Fragment buffer
+ * @v iphdr IPv4 header
+ * @ret frag Fragment reassembly buffer, or NULL
*/
-static void free_fragbuf ( struct frag_buffer *fragbuf ) {
- free ( fragbuf );
+static struct ipv4_fragment * ipv4_fragment ( struct iphdr *iphdr ) {
+ struct ipv4_fragment *frag;
+ struct iphdr *frag_iphdr;
+
+ list_for_each_entry ( frag, &ipv4_fragments, list ) {
+ frag_iphdr = frag->iobuf->data;
+
+ if ( ( iphdr->src.s_addr == frag_iphdr->src.s_addr ) &&
+ ( iphdr->ident == frag_iphdr->ident ) ) {
+ return frag;
+ }
+ }
+
+ return NULL;
}
/**
* Fragment reassembler
*
- * @v iobuf I/O buffer, fragment of the datagram
- * @ret frag_iob Reassembled packet, or NULL
+ * @v iobuf I/O buffer
+ * @ret iobuf Reassembled packet, or NULL
*/
-static struct io_buffer * ipv4_reassemble ( struct io_buffer * iobuf ) {
+static struct io_buffer * ipv4_reassemble ( struct io_buffer *iobuf ) {
struct iphdr *iphdr = iobuf->data;
- struct frag_buffer *fragbuf;
-
- /**
- * Check if the fragment belongs to any fragment series
- */
- list_for_each_entry ( fragbuf, &frag_buffers, list ) {
- if ( fragbuf->ident == iphdr->ident &&
- fragbuf->src.s_addr == iphdr->src.s_addr ) {
- /**
- * Check if the packet is the expected fragment
- *
- * The offset of the new packet must be equal to the
- * length of the data accumulated so far (the length of
- * the reassembled I/O buffer
- */
- if ( iob_len ( fragbuf->frag_iob ) ==
- ( iphdr->frags & IP_MASK_OFFSET ) ) {
- /**
- * Append the contents of the fragment to the
- * reassembled I/O buffer
- */
- iob_pull ( iobuf, sizeof ( *iphdr ) );
- memcpy ( iob_put ( fragbuf->frag_iob,
- iob_len ( iobuf ) ),
- iobuf->data, iob_len ( iobuf ) );
- free_iob ( iobuf );
-
- /** Check if the fragment series is over */
- if ( ! ( iphdr->frags & IP_MASK_MOREFRAGS ) ) {
- iobuf = fragbuf->frag_iob;
- free_fragbuf ( fragbuf );
- return iobuf;
- }
-
- } else {
- /* Discard the fragment series */
- free_fragbuf ( fragbuf );
- free_iob ( iobuf );
- }
- return NULL;
- }
+ size_t offset = ( ( ntohs ( iphdr->frags ) & IP_MASK_OFFSET ) << 3 );
+ unsigned int more_frags = ( iphdr->frags & htons ( IP_MASK_MOREFRAGS ));
+ size_t hdrlen = ( ( iphdr->verhdrlen & IP_MASK_HLEN ) * 4 );
+ struct ipv4_fragment *frag;
+ size_t expected_offset;
+ struct io_buffer *new_iobuf;
+
+ /* Find matching fragment reassembly buffer, if any */
+ frag = ipv4_fragment ( iphdr );
+
+ /* Drop out-of-order fragments */
+ expected_offset = ( frag ? frag->offset : 0 );
+ if ( offset != expected_offset ) {
+ DBG ( "IPv4 dropping out-of-sequence fragment %04x (%zd+%zd, "
+ "expected %zd)\n", ntohs ( iphdr->ident ), offset,
+ ( iob_len ( iobuf ) - hdrlen ), expected_offset );
+ goto drop;
}
-
- /** Check if the fragment is the first in the fragment series */
- if ( iphdr->frags & IP_MASK_MOREFRAGS &&
- ( ( iphdr->frags & IP_MASK_OFFSET ) == 0 ) ) {
-
- /** Create a new fragment buffer */
- fragbuf = ( struct frag_buffer* ) malloc ( sizeof( *fragbuf ) );
- fragbuf->ident = iphdr->ident;
- fragbuf->src = iphdr->src;
-
- /* Set up the reassembly I/O buffer */
- fragbuf->frag_iob = alloc_iob ( IP_FRAG_IOB_SIZE );
- iob_pull ( iobuf, sizeof ( *iphdr ) );
- memcpy ( iob_put ( fragbuf->frag_iob, iob_len ( iobuf ) ),
+
+ /* Create or extend fragment reassembly buffer as applicable */
+ if ( frag == NULL ) {
+
+ /* Create new fragment reassembly buffer */
+ frag = zalloc ( sizeof ( *frag ) );
+ if ( ! frag )
+ goto drop;
+ list_add ( &frag->list, &ipv4_fragments );
+ frag->iobuf = iobuf;
+ frag->offset = ( iob_len ( iobuf ) - hdrlen );
+ timer_init ( &frag->timer, ipv4_fragment_expired, NULL );
+
+ } else {
+
+ /* Extend reassembly buffer */
+ iob_pull ( iobuf, hdrlen );
+ new_iobuf = alloc_iob ( iob_len ( frag->iobuf ) +
+ iob_len ( iobuf ) );
+ if ( ! new_iobuf ) {
+ DBG ( "IPv4 could not extend reassembly buffer to "
+ "%zd bytes\n",
+ ( iob_len ( frag->iobuf ) + iob_len ( iobuf ) ) );
+ goto drop;
+ }
+ memcpy ( iob_put ( new_iobuf, iob_len ( frag->iobuf ) ),
+ frag->iobuf->data, iob_len ( frag->iobuf ) );
+ memcpy ( iob_put ( new_iobuf, iob_len ( iobuf ) ),
iobuf->data, iob_len ( iobuf ) );
+ free_iob ( frag->iobuf );
+ frag->iobuf = new_iobuf;
+ frag->offset += iob_len ( iobuf );
free_iob ( iobuf );
+ iphdr = frag->iobuf->data;
+ iphdr->len = ntohs ( iob_len ( frag->iobuf ) );
+
+ /* Stop fragment reassembly timer */
+ stop_timer ( &frag->timer );
+
+ /* If this is the final fragment, return it */
+ if ( ! more_frags ) {
+ iobuf = frag->iobuf;
+ list_del ( &frag->list );
+ free ( frag );
+ return iobuf;
+ }
+ }
- /* Set the reassembly timer */
- timer_init ( &fragbuf->frag_timer, ipv4_frag_expired, NULL );
- start_timer_fixed ( &fragbuf->frag_timer, IP_FRAG_TIMEOUT );
+ /* (Re)start fragment reassembly timer */
+ start_timer_fixed ( &frag->timer, IP_FRAG_TIMEOUT );
- /* Add the fragment buffer to the list of fragment buffers */
- list_add ( &fragbuf->list, &frag_buffers );
- }
-
+ return NULL;
+
+ drop:
+ free_iob ( iobuf );
return NULL;
}
goto err;
}
+ /* Truncate packet to correct length */
+ iob_unput ( iobuf, ( iob_len ( iobuf ) - len ) );
+
/* Print IPv4 header for debugging */
DBG ( "IPv4 RX %s<-", inet_ntoa ( iphdr->dest ) );
DBG ( "%s len %d proto %d id %04x csum %04x\n",
goto err;
}
- /* Truncate packet to correct length, calculate pseudo-header
- * checksum and then strip off the IPv4 header.
- */
- iob_unput ( iobuf, ( iob_len ( iobuf ) - len ) );
- pshdr_csum = ipv4_pshdr_chksum ( iobuf, TCPIP_EMPTY_CSUM );
- iob_pull ( iobuf, hdrlen );
-
- /* Fragment reassembly */
- if ( ( iphdr->frags & htons ( IP_MASK_MOREFRAGS ) ) ||
- ( ( iphdr->frags & htons ( IP_MASK_OFFSET ) ) != 0 ) ) {
- /* Pass the fragment to ipv4_reassemble() which either
- * returns a fully reassembled I/O buffer or NULL.
+ /* Perform fragment reassembly if applicable */
+ if ( iphdr->frags & htons ( IP_MASK_OFFSET | IP_MASK_MOREFRAGS ) ) {
+ /* Pass the fragment to ipv4_reassemble() which returns
+ * either a fully reassembled I/O buffer or NULL.
*/
iobuf = ipv4_reassemble ( iobuf );
if ( ! iobuf )
return 0;
+ iphdr = iobuf->data;
+ hdrlen = ( ( iphdr->verhdrlen & IP_MASK_HLEN ) * 4 );
}
- /* Construct socket addresses and hand off to transport layer */
+ /* Construct socket addresses, calculate pseudo-header
+ * checksum, and hand off to transport layer
+ */
memset ( &src, 0, sizeof ( src ) );
src.sin.sin_family = AF_INET;
src.sin.sin_addr = iphdr->src;
memset ( &dest, 0, sizeof ( dest ) );
dest.sin.sin_family = AF_INET;
dest.sin.sin_addr = iphdr->dest;
+ pshdr_csum = ipv4_pshdr_chksum ( iobuf, TCPIP_EMPTY_CSUM );
+ iob_pull ( iobuf, hdrlen );
if ( ( rc = tcpip_rx ( iobuf, iphdr->protocol, &src.st,
&dest.st, pshdr_csum ) ) != 0 ) {
DBG ( "IPv4 received packet rejected by stack: %s\n",
projects / thirdparty / ipxe.git / commitdiff
