2460d96c19
[ Upstream commit 1ed1d592113959f00cc552c3b9f47ca2d157768f ]
virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr
gso_type, to avoid packets getting dropped for lack of a proto type.
Its protocol choice is a guess, especially in the case of UFO, where
the single VIRTIO_NET_HDR_GSO_UDP label covers both UFOv4 and UFOv6.
Skip this best effort if the field is already initialized. Whether
explicitly from userspace, or implicitly based on an earlier call to
dev_parse_header_protocol (which is more robust, but was introduced
after this patch).
Fixes: 9d2f67e43b ("net/packet: fix packet drop as of virtio gso")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20211220145027.2784293-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
207 lines
5.4 KiB
C
207 lines
5.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_VIRTIO_NET_H
|
|
#define _LINUX_VIRTIO_NET_H
|
|
|
|
#include <linux/if_vlan.h>
|
|
#include <uapi/linux/tcp.h>
|
|
#include <uapi/linux/udp.h>
|
|
#include <uapi/linux/virtio_net.h>
|
|
|
|
static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type)
|
|
{
|
|
switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
|
|
case VIRTIO_NET_HDR_GSO_TCPV4:
|
|
return protocol == cpu_to_be16(ETH_P_IP);
|
|
case VIRTIO_NET_HDR_GSO_TCPV6:
|
|
return protocol == cpu_to_be16(ETH_P_IPV6);
|
|
case VIRTIO_NET_HDR_GSO_UDP:
|
|
return protocol == cpu_to_be16(ETH_P_IP) ||
|
|
protocol == cpu_to_be16(ETH_P_IPV6);
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static inline int virtio_net_hdr_set_proto(struct sk_buff *skb,
|
|
const struct virtio_net_hdr *hdr)
|
|
{
|
|
if (skb->protocol)
|
|
return 0;
|
|
|
|
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
|
|
case VIRTIO_NET_HDR_GSO_TCPV4:
|
|
case VIRTIO_NET_HDR_GSO_UDP:
|
|
skb->protocol = cpu_to_be16(ETH_P_IP);
|
|
break;
|
|
case VIRTIO_NET_HDR_GSO_TCPV6:
|
|
skb->protocol = cpu_to_be16(ETH_P_IPV6);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
|
|
const struct virtio_net_hdr *hdr,
|
|
bool little_endian)
|
|
{
|
|
unsigned int gso_type = 0;
|
|
unsigned int thlen = 0;
|
|
unsigned int p_off = 0;
|
|
unsigned int ip_proto;
|
|
|
|
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
|
|
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
|
|
case VIRTIO_NET_HDR_GSO_TCPV4:
|
|
gso_type = SKB_GSO_TCPV4;
|
|
ip_proto = IPPROTO_TCP;
|
|
thlen = sizeof(struct tcphdr);
|
|
break;
|
|
case VIRTIO_NET_HDR_GSO_TCPV6:
|
|
gso_type = SKB_GSO_TCPV6;
|
|
ip_proto = IPPROTO_TCP;
|
|
thlen = sizeof(struct tcphdr);
|
|
break;
|
|
case VIRTIO_NET_HDR_GSO_UDP:
|
|
gso_type = SKB_GSO_UDP;
|
|
ip_proto = IPPROTO_UDP;
|
|
thlen = sizeof(struct udphdr);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
|
|
gso_type |= SKB_GSO_TCP_ECN;
|
|
|
|
if (hdr->gso_size == 0)
|
|
return -EINVAL;
|
|
}
|
|
|
|
skb_reset_mac_header(skb);
|
|
|
|
if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
|
|
u32 start = __virtio16_to_cpu(little_endian, hdr->csum_start);
|
|
u32 off = __virtio16_to_cpu(little_endian, hdr->csum_offset);
|
|
u32 needed = start + max_t(u32, thlen, off + sizeof(__sum16));
|
|
|
|
if (!pskb_may_pull(skb, needed))
|
|
return -EINVAL;
|
|
|
|
if (!skb_partial_csum_set(skb, start, off))
|
|
return -EINVAL;
|
|
|
|
p_off = skb_transport_offset(skb) + thlen;
|
|
if (!pskb_may_pull(skb, p_off))
|
|
return -EINVAL;
|
|
} else {
|
|
/* gso packets without NEEDS_CSUM do not set transport_offset.
|
|
* probe and drop if does not match one of the above types.
|
|
*/
|
|
if (gso_type && skb->network_header) {
|
|
struct flow_keys_basic keys;
|
|
|
|
if (!skb->protocol) {
|
|
__be16 protocol = dev_parse_header_protocol(skb);
|
|
|
|
if (!protocol)
|
|
virtio_net_hdr_set_proto(skb, hdr);
|
|
else if (!virtio_net_hdr_match_proto(protocol, hdr->gso_type))
|
|
return -EINVAL;
|
|
else
|
|
skb->protocol = protocol;
|
|
}
|
|
retry:
|
|
if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
|
|
NULL, 0, 0, 0,
|
|
0)) {
|
|
/* UFO does not specify ipv4 or 6: try both */
|
|
if (gso_type & SKB_GSO_UDP &&
|
|
skb->protocol == htons(ETH_P_IP)) {
|
|
skb->protocol = htons(ETH_P_IPV6);
|
|
goto retry;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
p_off = keys.control.thoff + thlen;
|
|
if (!pskb_may_pull(skb, p_off) ||
|
|
keys.basic.ip_proto != ip_proto)
|
|
return -EINVAL;
|
|
|
|
skb_set_transport_header(skb, keys.control.thoff);
|
|
} else if (gso_type) {
|
|
p_off = thlen;
|
|
if (!pskb_may_pull(skb, p_off))
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
|
|
u16 gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size);
|
|
unsigned int nh_off = p_off;
|
|
struct skb_shared_info *shinfo = skb_shinfo(skb);
|
|
|
|
/* UFO may not include transport header in gso_size. */
|
|
if (gso_type & SKB_GSO_UDP)
|
|
nh_off -= thlen;
|
|
|
|
/* Too small packets are not really GSO ones. */
|
|
if (skb->len - nh_off > gso_size) {
|
|
shinfo->gso_size = gso_size;
|
|
shinfo->gso_type = gso_type;
|
|
|
|
/* Header must be checked, and gso_segs computed. */
|
|
shinfo->gso_type |= SKB_GSO_DODGY;
|
|
shinfo->gso_segs = 0;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
|
|
struct virtio_net_hdr *hdr,
|
|
bool little_endian,
|
|
bool has_data_valid,
|
|
int vlan_hlen)
|
|
{
|
|
memset(hdr, 0, sizeof(*hdr)); /* no info leak */
|
|
|
|
if (skb_is_gso(skb)) {
|
|
struct skb_shared_info *sinfo = skb_shinfo(skb);
|
|
|
|
/* This is a hint as to how much should be linear. */
|
|
hdr->hdr_len = __cpu_to_virtio16(little_endian,
|
|
skb_headlen(skb));
|
|
hdr->gso_size = __cpu_to_virtio16(little_endian,
|
|
sinfo->gso_size);
|
|
if (sinfo->gso_type & SKB_GSO_TCPV4)
|
|
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
|
|
else if (sinfo->gso_type & SKB_GSO_TCPV6)
|
|
hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
|
|
else
|
|
return -EINVAL;
|
|
if (sinfo->gso_type & SKB_GSO_TCP_ECN)
|
|
hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
|
|
} else
|
|
hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
|
hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
|
|
hdr->csum_start = __cpu_to_virtio16(little_endian,
|
|
skb_checksum_start_offset(skb) + vlan_hlen);
|
|
hdr->csum_offset = __cpu_to_virtio16(little_endian,
|
|
skb->csum_offset);
|
|
} else if (has_data_valid &&
|
|
skb->ip_summed == CHECKSUM_UNNECESSARY) {
|
|
hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
|
|
} /* else everything is zero */
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* _LINUX_VIRTIO_NET_H */
|