libmemif: zero-copy-slave mode + header space
Slave is now able to dequeue buffers from rx queue and enqueue them to tx queue
(zero-copy operation). Slave can produce buffers with headroom, which will allow adding
encap without copy.
Change-Id: Ia189f8de1a68be787545ed46cf78d36403e7e9bf
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
diff --git a/extras/libmemif/examples/icmp_responder/icmp_proto.c b/extras/libmemif/examples/icmp_responder/icmp_proto.c
index b27abb6..e1d255a 100644
--- a/extras/libmemif/examples/icmp_responder/icmp_proto.c
+++ b/extras/libmemif/examples/icmp_responder/icmp_proto.c
@@ -37,6 +37,7 @@
#include <net/if_arp.h>
#include <asm/byteorder.h>
#include <byteswap.h>
+#include <assert.h>
#include <icmp_proto.h>
@@ -337,3 +338,188 @@
return 0;
}
+
+int
+generate_packet2 (void *pck, uint32_t * size, uint8_t saddr[4],
+ uint8_t daddr[4], uint8_t hw_daddr[6], uint32_t seq,
+ icmpr_flow_mode_t mode)
+{
+ struct ether_header *eh;
+ struct iphdr *ip;
+ struct icmphdr *icmp;
+
+ *size = 0;
+
+ if (mode == ICMPR_FLOW_MODE_ETH)
+ {
+ eh = (struct ether_header *) pck;
+ *size += generate_eth (eh, hw_daddr);
+ }
+
+ ip = (struct iphdr *) (pck + *size);
+ *size += generate_ip (ip, saddr, daddr);
+
+ icmp = (struct icmphdr *) (pck + *size);
+ *size += generate_icmp (icmp, seq);
+
+ ((struct icmphdr *) (pck + *size - sizeof (struct icmphdr)))->checksum =
+ cksum (pck + *size - sizeof (struct icmphdr), sizeof (struct icmphdr));
+
+ ip->tot_len = __bswap_16 (*size - sizeof (struct ether_header));
+ ip->check = 0;
+ ip->check = cksum (ip, sizeof (struct iphdr));
+
+ return 0;
+}
+
+#define GET_HEADER(out,hdr,src,off) do { \
+ out = (hdr*)(src + off); \
+ off += sizeof (hdr); \
+ } while (0)
+
+int
+resolve_packet2 (void *pck, uint32_t * size, uint8_t ip_addr[4])
+{
+ struct ether_header *eh;
+ struct ether_arp *eah;
+ struct iphdr *ip;
+ struct icmphdr *icmp;
+ uint32_t offset = 0;
+
+ if (pck == NULL)
+ return 0;
+
+ GET_HEADER (eh, struct ether_header, pck, offset);
+
+ memcpy (eh->ether_dhost, eh->ether_shost, 6);
+ memcpy (eh->ether_shost, "aaaaaa", 6);
+
+ if (eh->ether_type == 0x0608)
+ {
+ GET_HEADER (eah, struct ether_arp, pck, offset);
+ struct arphdr *arp = &eah->ea_hdr;
+
+ arp->ar_hrd = __bswap_16 (ARPHRD_ETHER);
+ arp->ar_pro = __bswap_16 (0x0800);
+
+ arp->ar_hln = 6;
+ arp->ar_pln = 4;
+
+ arp->ar_op = __bswap_16 (ARPOP_REPLY);
+
+ memcpy (eah->arp_tha, eah->arp_sha, 6);
+ memcpy (eah->arp_tpa, eah->arp_spa, 4);
+
+ memcpy (eah->arp_sha, eh->ether_shost, 6);
+ memcpy (eah->arp_spa, ip_addr, 4);
+ }
+
+ else if (eh->ether_type == 0x0008)
+ {
+ GET_HEADER (ip, struct iphdr, pck, offset);
+
+ if (ip->protocol == 1)
+ {
+ ip->ihl = 5;
+ ip->version = 4;
+ ip->tos = 0;
+ ip->tot_len = 0x0000;
+ ip->id = 0;
+ ip->frag_off = 0;
+ ip->ttl = 0x40;
+ ip->protocol = 1;
+ ip->check = 0x0000;
+ ip->daddr = ip->saddr;
+ ((uint8_t *) & ip->saddr)[0] = ip_addr[0];
+ ((uint8_t *) & ip->saddr)[1] = ip_addr[1];
+ ((uint8_t *) & ip->saddr)[2] = ip_addr[2];
+ ((uint8_t *) & ip->saddr)[3] = ip_addr[3];
+
+ GET_HEADER (icmp, struct icmphdr, pck, offset);
+
+ icmp->type = 0x00;
+ icmp->code = 0;
+ icmp->checksum = cksum (icmp, sizeof (struct icmphdr));
+
+ /* rest is payload */
+ offset = *size;
+
+ ip->tot_len = __bswap_16 (offset - sizeof (struct ether_header));
+ ip->check = cksum (ip, sizeof (struct iphdr));
+ }
+ }
+
+ assert (offset == *size && "unsupported protocol");
+ return 0;
+}
+
+
+int
+resolve_packet3 (void **pck_, uint32_t * size, uint8_t ip_addr[4])
+{
+ struct ether_header *eh;
+ struct ether_arp *eah;
+ struct iphdr *ip;
+ struct icmphdr *icmp;
+ int32_t offset = 0;
+ uint16_t encap_size = sizeof (struct ether_header);
+ void *pck = *pck_;
+
+ if (pck == NULL)
+ return 0;
+
+ *pck_ -= encap_size;
+ offset -= encap_size;
+
+ GET_HEADER (eh, struct ether_header, pck, offset);
+
+ uint8_t hw_daddr[6];
+ memset (hw_daddr, 0, sizeof (uint8_t) * 6);
+
+ generate_eth (eh, hw_daddr);
+
+ if (eh->ether_type == 0x0008)
+ {
+ GET_HEADER (ip, struct iphdr, pck, offset);
+
+ if (ip->protocol == 1)
+ {
+ ip->ihl = 5;
+ ip->version = 4;
+ ip->tos = 0;
+ ip->tot_len = 0x0000;
+ ip->id = 0;
+ ip->frag_off = 0;
+ ip->ttl = 0x40;
+ ip->protocol = 1;
+ ip->check = 0x0000;
+ ip->daddr = ip->saddr;
+ ((uint8_t *) & ip->saddr)[0] = ip_addr[0];
+ ((uint8_t *) & ip->saddr)[1] = ip_addr[1];
+ ((uint8_t *) & ip->saddr)[2] = ip_addr[2];
+ ((uint8_t *) & ip->saddr)[3] = ip_addr[3];
+
+ GET_HEADER (icmp, struct icmphdr, pck, offset);
+
+ icmp->type = 0x00;
+ icmp->code = 0;
+ icmp->checksum = cksum (icmp, sizeof (struct icmphdr));
+
+ /* rest is payload */
+ offset = *size;
+
+ ip->tot_len = __bswap_16 (offset - sizeof (struct ether_header));
+ ip->check = cksum (ip, sizeof (struct iphdr));
+ }
+ }
+
+ offset += encap_size;
+
+ assert (offset != *size &&
+ "new packet length must be increased by encap size");
+
+ /* overwrite packet size */
+ *size = offset;
+
+ return 0;
+}