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Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging

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# gpg: Signature made Mon 25 Nov 2024 06:02:00 GMT
# gpg:                using RSA key 215D46F48246689EC77F3562EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* tag 'net-pull-request' of https://github.com/jasowang/qemu:
  virtio-net: Copy received header to buffer
  virtio-net: Initialize hash reporting values
  virtio-net: Fix hash reporting when the queue changes
  virtio-net: Do not check for the queue before RSS
  virtio-net: Fix size check in dhclient workaround
  net: checksum: Convert data to void *

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/net/virtio-net.c

@@ -1695,38 +1695,44 @@ static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
  * cache.
  */
 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
-                                        uint8_t *buf, size_t size)
+                                        size_t *hdr_len, const uint8_t *buf,
+                                        size_t buf_size, size_t *buf_offset)
 {
+    size_t csum_size = ETH_HLEN + sizeof(struct ip_header) +
+                       sizeof(struct udp_header);
+
+    buf += *buf_offset;
+    buf_size -= *buf_offset;
+
     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
-        (size > 27 && size < 1500) && /* normal sized MTU */
+        (buf_size >= csum_size && buf_size < 1500) && /* normal sized MTU */
         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
         (buf[23] == 17) && /* ip.protocol == UDP */
         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
-        net_checksum_calculate(buf, size, CSUM_UDP);
+        memcpy((uint8_t *)hdr + *hdr_len, buf, csum_size);
+        net_checksum_calculate((uint8_t *)hdr + *hdr_len, csum_size, CSUM_UDP);
         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
+        *hdr_len += csum_size;
+        *buf_offset += csum_size;
     }
 }
 
-static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
+static size_t receive_header(VirtIONet *n, struct virtio_net_hdr *hdr,
-                           const void *buf, size_t size)
+                             const void *buf, size_t buf_size,
+                             size_t *buf_offset)
 {
-    if (n->has_vnet_hdr) {
+    size_t hdr_len = n->guest_hdr_len;
-        /* FIXME this cast is evil */
-        void *wbuf = (void *)buf;
-        work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
-                                    size - n->host_hdr_len);
 
-        if (n->needs_vnet_hdr_swap) {
+    memcpy(hdr, buf, sizeof(struct virtio_net_hdr));
-            virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
+
-        }
+    *buf_offset = n->host_hdr_len;
-        iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
+    work_around_broken_dhclient(hdr, &hdr_len, buf, buf_size, buf_offset);
-    } else {
+
-        struct virtio_net_hdr hdr = {
+    if (n->needs_vnet_hdr_swap) {
-            .flags = 0,
+        virtio_net_hdr_swap(VIRTIO_DEVICE(n), hdr);
-            .gso_type = VIRTIO_NET_HDR_GSO_NONE
-        };
-        iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
     }
+
+    return hdr_len;
 }
 
 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
@@ -1894,32 +1900,41 @@ static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
     return (index == new_index) ? -1 : new_index;
 }
 
+typedef struct Header {
+    struct virtio_net_hdr_v1_hash virtio_net;
+    struct eth_header eth;
+    struct ip_header ip;
+    struct udp_header udp;
+} Header;
+
 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
-                                      size_t size, bool no_rss)
+                                      size_t size)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
-    VirtIONetQueue *q = virtio_net_get_subqueue(nc);
+    VirtIONetQueue *q;
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
     size_t lens[VIRTQUEUE_MAX_SIZE];
     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
-    struct virtio_net_hdr_v1_hash extra_hdr;
+    Header hdr;
     unsigned mhdr_cnt = 0;
     size_t offset, i, guest_offset, j;
     ssize_t err;
 
+    memset(&hdr.virtio_net, 0, sizeof(hdr.virtio_net));
+
+    if (n->rss_data.enabled && n->rss_data.enabled_software_rss) {
+        int index = virtio_net_process_rss(nc, buf, size, &hdr.virtio_net);
+        if (index >= 0) {
+            nc = qemu_get_subqueue(n->nic, index % n->curr_queue_pairs);
+        }
+    }
+
     if (!virtio_net_can_receive(nc)) {
         return -1;
     }
 
-    if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
+    q = virtio_net_get_subqueue(nc);
-        int index = virtio_net_process_rss(nc, buf, size, &extra_hdr);
-        if (index >= 0) {
-            NetClientState *nc2 =
-                qemu_get_subqueue(n->nic, index % n->curr_queue_pairs);
-            return virtio_net_receive_rcu(nc2, buf, size, true);
-        }
-    }
 
     /* hdr_len refers to the header we supply to the guest */
     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
@@ -1974,21 +1989,18 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
             if (n->mergeable_rx_bufs) {
                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
                                     sg, elem->in_num,
-                                    offsetof(typeof(extra_hdr), hdr.num_buffers),
+                                    offsetof(typeof(hdr),
-                                    sizeof(extra_hdr.hdr.num_buffers));
+                                             virtio_net.hdr.num_buffers),
+                                    sizeof(hdr.virtio_net.hdr.num_buffers));
             }
 
-            receive_header(n, sg, elem->in_num, buf, size);
+            guest_offset = n->has_vnet_hdr ?
-            if (n->rss_data.populate_hash) {
+                           receive_header(n, (struct virtio_net_hdr *)&hdr,
-                offset = offsetof(typeof(extra_hdr), hash_value);
+                                          buf, size, &offset) :
-                iov_from_buf(sg, elem->in_num, offset,
+                           n->guest_hdr_len;
-                             (char *)&extra_hdr + offset,
+
-                             sizeof(extra_hdr.hash_value) +
+            iov_from_buf(sg, elem->in_num, 0, &hdr, guest_offset);
-                             sizeof(extra_hdr.hash_report));
+            total += guest_offset;
-            }
-            offset = n->host_hdr_len;
-            total += n->guest_hdr_len;
-            guest_offset = n->guest_hdr_len;
         } else {
             guest_offset = 0;
         }
@@ -2014,11 +2026,11 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
     }
 
     if (mhdr_cnt) {
-        virtio_stw_p(vdev, &extra_hdr.hdr.num_buffers, i);
+        virtio_stw_p(vdev, &hdr.virtio_net.hdr.num_buffers, i);
         iov_from_buf(mhdr_sg, mhdr_cnt,
                      0,
-                     &extra_hdr.hdr.num_buffers,
+                     &hdr.virtio_net.hdr.num_buffers,
-                     sizeof extra_hdr.hdr.num_buffers);
+                     sizeof hdr.virtio_net.hdr.num_buffers);
     }
 
     for (j = 0; j < i; j++) {
@@ -2046,7 +2058,7 @@ static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
 {
     RCU_READ_LOCK_GUARD();
 
-    return virtio_net_receive_rcu(nc, buf, size, false);
+    return virtio_net_receive_rcu(nc, buf, size);
 }
 
 /*

include/net/checksum.h

@@ -30,7 +30,7 @@ uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
 uint16_t net_checksum_finish(uint32_t sum);
 uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
                              uint8_t *addrs, uint8_t *buf);
-void net_checksum_calculate(uint8_t *data, int length, int csum_flag);
+void net_checksum_calculate(void *data, int length, int csum_flag);
 
 static inline uint32_t
 net_checksum_add(int len, uint8_t *buf)

net/checksum.c

@@ -57,7 +57,7 @@ uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
     return net_checksum_finish(sum);
 }
 
-void net_checksum_calculate(uint8_t *data, int length, int csum_flag)
+void net_checksum_calculate(void *data, int length, int csum_flag)
 {
     int mac_hdr_len, ip_len;
     struct ip_header *ip;
@@ -101,7 +101,7 @@ void net_checksum_calculate(uint8_t *data, int length, int csum_flag)
         return;
     }
 
-    ip = (struct ip_header *)(data + mac_hdr_len);
+    ip = (struct ip_header *)((uint8_t *)data + mac_hdr_len);
 
     if (IP_HEADER_VERSION(ip) != IP_HEADER_VERSION_4) {
         return; /* not IPv4 */