net_pkt: Extend packet abstraction as required by e1000e functionality

This patch extends the TX/RX packet abstractions with features that will
be used by the e1000e device implementation.

Changes are:

  1. Support iovec lists for RX buffers
  2. Deeper RX packets parsing
  3. Loopback option for TX packets
  4. Extended VLAN headers handling
  5. RSS processing for RX packets

Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Leonid Bloch <leonid.bloch@ravellosystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 443 insertions, 30 deletions

diff --git a/hw/net/net_rx_pkt.c b/hw/net/net_rx_pkt.c
index 8a4f29fe04..1019b50c18 100644
--- a/hw/net/net_rx_pkt.c
+++ b/hw/net/net_rx_pkt.c
@@ -16,24 +16,16 @@
  */
 
 #include "qemu/osdep.h"
+#include "trace.h"
 #include "net_rx_pkt.h"
-#include "net/eth.h"
-#include "qemu-common.h"
-#include "qemu/iov.h"
 #include "net/checksum.h"
 #include "net/tap.h"
 
-/*
- * RX packet may contain up to 2 fragments - rebuilt eth header
- * in case of VLAN tag stripping
- * and payload received from QEMU - in any case
- */
-#define NET_MAX_RX_PACKET_FRAGMENTS (2)
-
 struct NetRxPkt {
     struct virtio_net_hdr virt_hdr;
-    uint8_t ehdr_buf[ETH_MAX_L2_HDR_LEN];
-    struct iovec vec[NET_MAX_RX_PACKET_FRAGMENTS];
+    uint8_t ehdr_buf[sizeof(struct eth_header)];
+    struct iovec *vec;
+    uint16_t vec_len_total;
     uint16_t vec_len;
     uint32_t tot_len;
     uint16_t tci;
@@ -46,17 +38,31 @@ struct NetRxPkt {
     bool isip6;
     bool isudp;
     bool istcp;
+
+    size_t l3hdr_off;
+    size_t l4hdr_off;
+    size_t l5hdr_off;
+
+    eth_ip6_hdr_info ip6hdr_info;
+    eth_ip4_hdr_info ip4hdr_info;
+    eth_l4_hdr_info  l4hdr_info;
 };
 
 void net_rx_pkt_init(struct NetRxPkt **pkt, bool has_virt_hdr)
 {
     struct NetRxPkt *p = g_malloc0(sizeof *p);
     p->has_virt_hdr = has_virt_hdr;
+    p->vec = NULL;
+    p->vec_len_total = 0;
     *pkt = p;
 }
 
 void net_rx_pkt_uninit(struct NetRxPkt *pkt)
 {
+    if (pkt->vec_len_total != 0) {
+        g_free(pkt->vec);
+    }
+
     g_free(pkt);
 }
 
@@ -66,33 +72,88 @@ struct virtio_net_hdr *net_rx_pkt_get_vhdr(struct NetRxPkt *pkt)
     return &pkt->virt_hdr;
 }
 
-void net_rx_pkt_attach_data(struct NetRxPkt *pkt, const void *data,
-                               size_t len, bool strip_vlan)
+static inline void
+net_rx_pkt_iovec_realloc(struct NetRxPkt *pkt,
+                            int new_iov_len)
+{
+    if (pkt->vec_len_total < new_iov_len) {
+        g_free(pkt->vec);
+        pkt->vec = g_malloc(sizeof(*pkt->vec) * new_iov_len);
+        pkt->vec_len_total = new_iov_len;
+    }
+}
+
+static void
+net_rx_pkt_pull_data(struct NetRxPkt *pkt,
+                        const struct iovec *iov, int iovcnt,
+                        size_t ploff)
+{
+    if (pkt->vlan_stripped) {
+        net_rx_pkt_iovec_realloc(pkt, iovcnt + 1);
+
+        pkt->vec[0].iov_base = pkt->ehdr_buf;
+        pkt->vec[0].iov_len = sizeof(pkt->ehdr_buf);
+
+        pkt->tot_len =
+            iov_size(iov, iovcnt) - ploff + sizeof(struct eth_header);
+
+        pkt->vec_len = iov_copy(pkt->vec + 1, pkt->vec_len_total - 1,
+                                iov, iovcnt, ploff, pkt->tot_len);
+    } else {
+        net_rx_pkt_iovec_realloc(pkt, iovcnt);
+
+        pkt->tot_len = iov_size(iov, iovcnt) - ploff;
+        pkt->vec_len = iov_copy(pkt->vec, pkt->vec_len_total,
+                                iov, iovcnt, ploff, pkt->tot_len);
+    }
+
+    eth_get_protocols(pkt->vec, pkt->vec_len, &pkt->isip4, &pkt->isip6,
+                      &pkt->isudp, &pkt->istcp,
+                      &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
+                      &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
+
+    trace_net_rx_pkt_parsed(pkt->isip4, pkt->isip6, pkt->isudp, pkt->istcp,
+                            pkt->l3hdr_off, pkt->l4hdr_off, pkt->l5hdr_off);
+}
+
+void net_rx_pkt_attach_iovec(struct NetRxPkt *pkt,
+                                const struct iovec *iov, int iovcnt,
+                                size_t iovoff, bool strip_vlan)
 {
     uint16_t tci = 0;
-    uint16_t ploff;
+    uint16_t ploff = iovoff;
     assert(pkt);
     pkt->vlan_stripped = false;
 
     if (strip_vlan) {
-        pkt->vlan_stripped = eth_strip_vlan(data, pkt->ehdr_buf, &ploff, &tci);
+        pkt->vlan_stripped = eth_strip_vlan(iov, iovcnt, iovoff, pkt->ehdr_buf,
+                                            &ploff, &tci);
     }
 
-    if (pkt->vlan_stripped) {
-        pkt->vec[0].iov_base = pkt->ehdr_buf;
-        pkt->vec[0].iov_len = ploff - sizeof(struct vlan_header);
-        pkt->vec[1].iov_base = (uint8_t *) data + ploff;
-        pkt->vec[1].iov_len = len - ploff;
-        pkt->vec_len = 2;
-        pkt->tot_len = len - ploff + sizeof(struct eth_header);
-    } else {
-        pkt->vec[0].iov_base = (void *)data;
-        pkt->vec[0].iov_len = len;
-        pkt->vec_len = 1;
-        pkt->tot_len = len;
+    pkt->tci = tci;
+
+    net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
+}
+
+void net_rx_pkt_attach_iovec_ex(struct NetRxPkt *pkt,
+                                const struct iovec *iov, int iovcnt,
+                                size_t iovoff, bool strip_vlan,
+                                uint16_t vet)
+{
+    uint16_t tci = 0;
+    uint16_t ploff = iovoff;
+    assert(pkt);
+    pkt->vlan_stripped = false;
+
+    if (strip_vlan) {
+        pkt->vlan_stripped = eth_strip_vlan_ex(iov, iovcnt, iovoff, vet,
+                                               pkt->ehdr_buf,
+                                               &ploff, &tci);
     }
 
     pkt->tci = tci;
+
+    net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 }
 
 void net_rx_pkt_dump(struct NetRxPkt *pkt)
@@ -132,10 +193,17 @@ size_t net_rx_pkt_get_total_len(struct NetRxPkt *pkt)
 void net_rx_pkt_set_protocols(struct NetRxPkt *pkt, const void *data,
                               size_t len)
 {
+    const struct iovec iov = {
+        .iov_base = (void *)data,
+        .iov_len = len
+    };
+
     assert(pkt);
 
-    eth_get_protocols(data, len, &pkt->isip4, &pkt->isip6,
-        &pkt->isudp, &pkt->istcp);
+    eth_get_protocols(&iov, 1, &pkt->isip4, &pkt->isip6,
+                      &pkt->isudp, &pkt->istcp,
+                      &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
+                      &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
 }
 
 void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
@@ -150,6 +218,180 @@ void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
     *istcp = pkt->istcp;
 }
 
+size_t net_rx_pkt_get_l3_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l3hdr_off;
+}
+
+size_t net_rx_pkt_get_l4_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l4hdr_off;
+}
+
+size_t net_rx_pkt_get_l5_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l5hdr_off;
+}
+
+eth_ip6_hdr_info *net_rx_pkt_get_ip6_info(struct NetRxPkt *pkt)
+{
+    return &pkt->ip6hdr_info;
+}
+
+eth_ip4_hdr_info *net_rx_pkt_get_ip4_info(struct NetRxPkt *pkt)
+{
+    return &pkt->ip4hdr_info;
+}
+
+eth_l4_hdr_info *net_rx_pkt_get_l4_info(struct NetRxPkt *pkt)
+{
+    return &pkt->l4hdr_info;
+}
+
+static inline void
+_net_rx_rss_add_chunk(uint8_t *rss_input, size_t *bytes_written,
+                      void *ptr, size_t size)
+{
+    memcpy(&rss_input[*bytes_written], ptr, size);
+    trace_net_rx_pkt_rss_add_chunk(ptr, size, *bytes_written);
+    *bytes_written += size;
+}
+
+static inline void
+_net_rx_rss_prepare_ip4(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        size_t *bytes_written)
+{
+    struct ip_header *ip4_hdr = &pkt->ip4hdr_info.ip4_hdr;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &ip4_hdr->ip_src, sizeof(uint32_t));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &ip4_hdr->ip_dst, sizeof(uint32_t));
+}
+
+static inline void
+_net_rx_rss_prepare_ip6(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        bool ipv6ex, size_t *bytes_written)
+{
+    eth_ip6_hdr_info *ip6info = &pkt->ip6hdr_info;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+           (ipv6ex && ip6info->rss_ex_src_valid) ? &ip6info->rss_ex_src
+                                                 : &ip6info->ip6_hdr.ip6_src,
+           sizeof(struct in6_address));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+           (ipv6ex && ip6info->rss_ex_dst_valid) ? &ip6info->rss_ex_dst
+                                                 : &ip6info->ip6_hdr.ip6_dst,
+           sizeof(struct in6_address));
+}
+
+static inline void
+_net_rx_rss_prepare_tcp(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        size_t *bytes_written)
+{
+    struct tcp_header *tcphdr = &pkt->l4hdr_info.hdr.tcp;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &tcphdr->th_sport, sizeof(uint16_t));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &tcphdr->th_dport, sizeof(uint16_t));
+}
+
+uint32_t
+net_rx_pkt_calc_rss_hash(struct NetRxPkt *pkt,
+                         NetRxPktRssType type,
+                         uint8_t *key)
+{
+    uint8_t rss_input[36];
+    size_t rss_length = 0;
+    uint32_t rss_hash = 0;
+    net_toeplitz_key key_data;
+
+    switch (type) {
+    case NetPktRssIpV4:
+        assert(pkt->isip4);
+        trace_net_rx_pkt_rss_ip4();
+        _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV4Tcp:
+        assert(pkt->isip4);
+        assert(pkt->istcp);
+        trace_net_rx_pkt_rss_ip4_tcp();
+        _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
+        _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV6Tcp:
+        assert(pkt->isip6);
+        assert(pkt->istcp);
+        trace_net_rx_pkt_rss_ip6_tcp();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
+        _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV6:
+        assert(pkt->isip6);
+        trace_net_rx_pkt_rss_ip6();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, false, &rss_length);
+        break;
+    case NetPktRssIpV6Ex:
+        assert(pkt->isip6);
+        trace_net_rx_pkt_rss_ip6_ex();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
+        break;
+    default:
+        assert(false);
+        break;
+    }
+
+    net_toeplitz_key_init(&key_data, key);
+    net_toeplitz_add(&rss_hash, rss_input, rss_length, &key_data);
+
+    trace_net_rx_pkt_rss_hash(rss_length, rss_hash);
+
+    return rss_hash;
+}
+
+uint16_t net_rx_pkt_get_ip_id(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->isip4) {
+        return be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_id);
+    }
+
+    return 0;
+}
+
+bool net_rx_pkt_is_tcp_ack(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->istcp) {
+        return TCP_HEADER_FLAGS(&pkt->l4hdr_info.hdr.tcp) & TCP_FLAG_ACK;
+    }
+
+    return false;
+}
+
+bool net_rx_pkt_has_tcp_data(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->istcp) {
+        return pkt->l4hdr_info.has_tcp_data;
+    }
+
+    return false;
+}
+
 struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
 {
     assert(pkt);
@@ -157,6 +399,13 @@ struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
     return pkt->vec;
 }
 
+uint16_t net_rx_pkt_get_iovec_len(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    return pkt->vec_len;
+}
+
 void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
                             struct virtio_net_hdr *vhdr)
 {
@@ -165,6 +414,14 @@ void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
     memcpy(&pkt->virt_hdr, vhdr, sizeof pkt->virt_hdr);
 }
 
+void net_rx_pkt_set_vhdr_iovec(struct NetRxPkt *pkt,
+    const struct iovec *iov, int iovcnt)
+{
+    assert(pkt);
+
+    iov_to_buf(iov, iovcnt, 0, &pkt->virt_hdr, sizeof pkt->virt_hdr);
+}
+
 bool net_rx_pkt_is_vlan_stripped(struct NetRxPkt *pkt)
 {
     assert(pkt);
@@ -185,3 +442,159 @@ uint16_t net_rx_pkt_get_vlan_tag(struct NetRxPkt *pkt)
 
     return pkt->tci;
 }
+
+bool net_rx_pkt_validate_l3_csum(struct NetRxPkt *pkt, bool *csum_valid)
+{
+    uint32_t cntr;
+    uint16_t csum;
+    uint32_t csl;
+
+    trace_net_rx_pkt_l3_csum_validate_entry();
+
+    if (!pkt->isip4) {
+        trace_net_rx_pkt_l3_csum_validate_not_ip4();
+        return false;
+    }
+
+    csl = pkt->l4hdr_off - pkt->l3hdr_off;
+
+    cntr = net_checksum_add_iov(pkt->vec, pkt->vec_len,
+                                pkt->l3hdr_off,
+                                csl, 0);
+
+    csum = net_checksum_finish(cntr);
+
+    *csum_valid = (csum == 0);
+
+    trace_net_rx_pkt_l3_csum_validate_csum(pkt->l3hdr_off, csl,
+                                           cntr, csum, *csum_valid);
+
+    return true;
+}
+
+static uint16_t
+_net_rx_pkt_calc_l4_csum(struct NetRxPkt *pkt)
+{
+    uint32_t cntr;
+    uint16_t csum;
+    uint16_t csl;
+    uint32_t cso;
+
+    trace_net_rx_pkt_l4_csum_calc_entry();
+
+    if (pkt->isip4) {
+        if (pkt->isudp) {
+            csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
+            trace_net_rx_pkt_l4_csum_calc_ip4_udp();
+        } else {
+            csl = be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_len) -
+                  IP_HDR_GET_LEN(&pkt->ip4hdr_info.ip4_hdr);
+            trace_net_rx_pkt_l4_csum_calc_ip4_tcp();
+        }
+
+        cntr = eth_calc_ip4_pseudo_hdr_csum(&pkt->ip4hdr_info.ip4_hdr,
+                                            csl, &cso);
+        trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
+    } else {
+        if (pkt->isudp) {
+            csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
+            trace_net_rx_pkt_l4_csum_calc_ip6_udp();
+        } else {
+            struct ip6_header *ip6hdr = &pkt->ip6hdr_info.ip6_hdr;
+            size_t full_ip6hdr_len = pkt->l4hdr_off - pkt->l3hdr_off;
+            size_t ip6opts_len = full_ip6hdr_len - sizeof(struct ip6_header);
+
+            csl = be16_to_cpu(ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen) -
+                  ip6opts_len;
+            trace_net_rx_pkt_l4_csum_calc_ip6_tcp();
+        }
+
+        cntr = eth_calc_ip6_pseudo_hdr_csum(&pkt->ip6hdr_info.ip6_hdr, csl,
+                                            pkt->ip6hdr_info.l4proto, &cso);
+        trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
+    }
+
+    cntr += net_checksum_add_iov(pkt->vec, pkt->vec_len,
+                                 pkt->l4hdr_off, csl, cso);
+
+    csum = net_checksum_finish(cntr);
+
+    trace_net_rx_pkt_l4_csum_calc_csum(pkt->l4hdr_off, csl, cntr, csum);
+
+    return csum;
+}
+
+bool net_rx_pkt_validate_l4_csum(struct NetRxPkt *pkt, bool *csum_valid)
+{
+    uint16_t csum;
+
+    trace_net_rx_pkt_l4_csum_validate_entry();
+
+    if (!pkt->istcp && !pkt->isudp) {
+        trace_net_rx_pkt_l4_csum_validate_not_xxp();
+        return false;
+    }
+
+    if (pkt->isudp && (pkt->l4hdr_info.hdr.udp.uh_sum == 0)) {
+        trace_net_rx_pkt_l4_csum_validate_udp_with_no_checksum();
+        return false;
+    }
+
+    if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
+        trace_net_rx_pkt_l4_csum_validate_ip4_fragment();
+        return false;
+    }
+
+    csum = _net_rx_pkt_calc_l4_csum(pkt);
+
+    *csum_valid = ((csum == 0) || (csum == 0xFFFF));
+
+    trace_net_rx_pkt_l4_csum_validate_csum(*csum_valid);
+
+    return true;
+}
+
+bool net_rx_pkt_fix_l4_csum(struct NetRxPkt *pkt)
+{
+    uint16_t csum = 0;
+    uint32_t l4_cso;
+
+    trace_net_rx_pkt_l4_csum_fix_entry();
+
+    if (pkt->istcp) {
+        l4_cso = offsetof(struct tcp_header, th_sum);
+        trace_net_rx_pkt_l4_csum_fix_tcp(l4_cso);
+    } else if (pkt->isudp) {
+        if (pkt->l4hdr_info.hdr.udp.uh_sum == 0) {
+            trace_net_rx_pkt_l4_csum_fix_udp_with_no_checksum();
+            return false;
+        }
+        l4_cso = offsetof(struct udp_header, uh_sum);
+        trace_net_rx_pkt_l4_csum_fix_udp(l4_cso);
+    } else {
+        trace_net_rx_pkt_l4_csum_fix_not_xxp();
+        return false;
+    }
+
+    if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
+            trace_net_rx_pkt_l4_csum_fix_ip4_fragment();
+            return false;
+    }
+
+    /* Set zero to checksum word */
+    iov_from_buf(pkt->vec, pkt->vec_len,
+                 pkt->l4hdr_off + l4_cso,
+                 &csum, sizeof(csum));
+
+    /* Calculate L4 checksum */
+    csum = cpu_to_be16(_net_rx_pkt_calc_l4_csum(pkt));
+
+    /* Set calculated checksum to checksum word */
+    iov_from_buf(pkt->vec, pkt->vec_len,
+                 pkt->l4hdr_off + l4_cso,
+                 &csum, sizeof(csum));
+
+    trace_net_rx_pkt_l4_csum_fix_csum(pkt->l4hdr_off + l4_cso, csum);
+
+    return true;
+}