On Tue, Jun 15, 2021 at 9:06 AM Xiao Wang <xiao.w.w...@intel.com> wrote:
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index 8da8a86a10..351ff0a841 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -2259,44 +2259,64 @@ virtio_net_with_host_offload(struct virtio_net *dev)
> return false;
> }
>
> -static void
> -parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
> +static int
> +parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr,
> + uint16_t *len)
> {
This function name is misleading, name could be parse_headers().
Its semantic gets more and more confusing with those l4_hdr and len pointers.
This function fills ->lX_len in the mbuf, everything is available for caller.
Caller can check that rte_pktmbuf_data_len() is >= m->l2_len +
m->l3_len + somesize.
=> no need for len.
l4_hdr can simply be deduced with rte_pktmbuf_mtod_offset(m, struct
somestruct *, m->l2_len + m->l3_len).
=> no need for l4_hdr.
> struct rte_ipv4_hdr *ipv4_hdr;
> struct rte_ipv6_hdr *ipv6_hdr;
> void *l3_hdr = NULL;
No need for l3_hdr.
> struct rte_ether_hdr *eth_hdr;
> uint16_t ethertype;
> + uint16_t data_len = m->data_len;
Avoid direct access to mbuf internals, we have inline helpers:
rte_pktmbuf_data_len(m).
> +
> + if (data_len <= sizeof(struct rte_ether_hdr))
Strictly speaking, < is enough.
> + return -EINVAL;
>
> eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
>
> m->l2_len = sizeof(struct rte_ether_hdr);
> ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
> + data_len -= sizeof(struct rte_ether_hdr);
No need to decrement data_len if checks below are all done for absolute value.
See suggestions below.
>
> if (ethertype == RTE_ETHER_TYPE_VLAN) {
> + if (data_len <= sizeof(struct rte_vlan_hdr))
> + return -EINVAL;
if (data_len < sizeof(rte_ether_hdr) + sizeof(struct rte_vlan_hdr))
> +
> struct rte_vlan_hdr *vlan_hdr =
> (struct rte_vlan_hdr *)(eth_hdr + 1);
>
> m->l2_len += sizeof(struct rte_vlan_hdr);
> ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
> + data_len -= sizeof(struct rte_vlan_hdr);
Idem.
> }
>
> l3_hdr = (char *)eth_hdr + m->l2_len;
>
> switch (ethertype) {
> case RTE_ETHER_TYPE_IPV4:
> + if (data_len <= sizeof(struct rte_ipv4_hdr))
> + return -EINVAL;
if (data_len < m->l2_len + sizeof(struct rte_ipv4_hdr))
> ipv4_hdr = l3_hdr;
ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv4_hdr *, m->l2_len);
> *l4_proto = ipv4_hdr->next_proto_id;
> m->l3_len = rte_ipv4_hdr_len(ipv4_hdr);
> + if (data_len <= m->l3_len) {
if (data_len < m->l2_len + m->l3_len)
> + m->l3_len = 0;
> + return -EINVAL;
Returning here leaves m->l2_len set.
> + }
> *l4_hdr = (char *)l3_hdr + m->l3_len;
> m->ol_flags |= PKT_TX_IPV4;
> + data_len -= m->l3_len;
> break;
> case RTE_ETHER_TYPE_IPV6:
> + if (data_len <= sizeof(struct rte_ipv6_hdr))
> + return -EINVAL;
if (data_len < m->l2_len + sizeof(struct rte_ipv6_hdr))
Returning here leaves m->l2_len set.
> ipv6_hdr = l3_hdr;
ipv6_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv6_hdr *, m->l2_len);
> *l4_proto = ipv6_hdr->proto;
> m->l3_len = sizeof(struct rte_ipv6_hdr);
> *l4_hdr = (char *)l3_hdr + m->l3_len;
> m->ol_flags |= PKT_TX_IPV6;
> + data_len -= m->l3_len;
> break;
> default:
> m->l3_len = 0;
> @@ -2304,6 +2324,9 @@ parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto,
> void **l4_hdr)
> *l4_hdr = NULL;
> break;
> }
> +
> + *len = data_len;
> + return 0;
> }
>
> static __rte_always_inline void
> @@ -2312,21 +2335,27 @@ vhost_dequeue_offload_legacy(struct virtio_net_hdr
> *hdr, struct rte_mbuf *m)
> uint16_t l4_proto = 0;
> void *l4_hdr = NULL;
> struct rte_tcp_hdr *tcp_hdr = NULL;
> + uint16_t len = 0, tcp_len;
> +
> + if (parse_ethernet(m, &l4_proto, &l4_hdr, &len) < 0)
> + return;
>
> - parse_ethernet(m, &l4_proto, &l4_hdr);
> if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
> if (hdr->csum_start == (m->l2_len + m->l3_len)) {
> switch (hdr->csum_offset) {
> case (offsetof(struct rte_tcp_hdr, cksum)):
> - if (l4_proto == IPPROTO_TCP)
> + if (l4_proto == IPPROTO_TCP &&
> + len >= sizeof(struct rte_tcp_hdr))
if (rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len + sizeof(struct
rte_tcp_hdr))
Then, if this check is wrong, we leave l2_len, l3_len + PKT_TX_IPVx
flag set in mbuf.
These two comments apply to other updates below.
> m->ol_flags |= PKT_TX_TCP_CKSUM;
> break;
> case (offsetof(struct rte_udp_hdr, dgram_cksum)):
> - if (l4_proto == IPPROTO_UDP)
> + if (l4_proto == IPPROTO_UDP &&
> + len >= sizeof(struct rte_udp_hdr))
> m->ol_flags |= PKT_TX_UDP_CKSUM;
> break;
> case (offsetof(struct rte_sctp_hdr, cksum)):
> - if (l4_proto == IPPROTO_SCTP)
> + if (l4_proto == IPPROTO_SCTP &&
> + len >= sizeof(struct rte_sctp_hdr))
> m->ol_flags |= PKT_TX_SCTP_CKSUM;
> break;
> default:
> @@ -2339,12 +2368,21 @@ vhost_dequeue_offload_legacy(struct virtio_net_hdr
> *hdr, struct rte_mbuf *m)
> switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
> case VIRTIO_NET_HDR_GSO_TCPV4:
> case VIRTIO_NET_HDR_GSO_TCPV6:
> + if (l4_proto != IPPROTO_TCP ||
> + len < sizeof(struct rte_tcp_hdr))
> + break;
> tcp_hdr = l4_hdr;
tcp_hdr = rte_pktmbuf_mtod_offset(m, struct rte_tcp_hdr *, m->l2_len +
m->l3_len);
> + tcp_len = (tcp_hdr->data_off & 0xf0) >> 2;
> + if (len < tcp_len)
> + break;
> m->ol_flags |= PKT_TX_TCP_SEG;
> m->tso_segsz = hdr->gso_size;
> - m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
> + m->l4_len = tcp_len;
> break;
> case VIRTIO_NET_HDR_GSO_UDP:
> + if (l4_proto != IPPROTO_UDP ||
> + len < sizeof(struct rte_udp_hdr))
> + break;
> m->ol_flags |= PKT_TX_UDP_SEG;
> m->tso_segsz = hdr->gso_size;
> m->l4_len = sizeof(struct rte_udp_hdr);
> --
> 2.15.1
>
--
David Marchand
