diff options
| author | Akihiko Odaki <akihiko.odaki@daynix.com> | 2025-02-07 15:10:56 +0900 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-02-10 19:07:11 -0800 |
| commit | 74212f20f366db41dd3148b951284ac38ef9bb10 (patch) | |
| tree | bb84b9dc4e24008534fd5e9b7a290edcdcf4f8ee | |
| parent | 1d41e2fa93f7d4dce4d05dfa2f980fba0898bea8 (diff) | |
tap: Keep hdr_len in tap_get_user()
hdr_len is repeatedly used so keep it in a local variable.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250207-tun-v6-6-fb49cf8b103e@daynix.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/tap.c | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 5ca6ecf0ce5f..21b77c261fea 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -645,6 +645,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, int err; struct virtio_net_hdr vnet_hdr = { 0 }; int vnet_hdr_len = 0; + int hdr_len = 0; int copylen = 0; int depth; bool zerocopy = false; @@ -663,13 +664,13 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from)) goto err; iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr)); - if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && - tap16_to_cpu(q, vnet_hdr.csum_start) + - tap16_to_cpu(q, vnet_hdr.csum_offset) + 2 > - tap16_to_cpu(q, vnet_hdr.hdr_len)) - vnet_hdr.hdr_len = cpu_to_tap16(q, - tap16_to_cpu(q, vnet_hdr.csum_start) + - tap16_to_cpu(q, vnet_hdr.csum_offset) + 2); + hdr_len = tap16_to_cpu(q, vnet_hdr.hdr_len); + if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len = max(tap16_to_cpu(q, vnet_hdr.csum_start) + + tap16_to_cpu(q, vnet_hdr.csum_offset) + 2, + hdr_len); + vnet_hdr.hdr_len = cpu_to_tap16(q, hdr_len); + } err = -EINVAL; if (tap16_to_cpu(q, vnet_hdr.hdr_len) > len) goto err; @@ -682,12 +683,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { struct iov_iter i; - copylen = vnet_hdr.hdr_len ? - tap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; - if (copylen > good_linear) - copylen = good_linear; - else if (copylen < ETH_HLEN) - copylen = ETH_HLEN; + copylen = clamp(hdr_len ?: GOODCOPY_LEN, ETH_HLEN, good_linear); linear = copylen; i = *from; iov_iter_advance(&i, copylen); @@ -697,11 +693,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, if (!zerocopy) { copylen = len; - linear = tap16_to_cpu(q, vnet_hdr.hdr_len); - if (linear > good_linear) - linear = good_linear; - else if (linear < ETH_HLEN) - linear = ETH_HLEN; + linear = clamp(hdr_len, ETH_HLEN, good_linear); } skb = tap_alloc_skb(&q->sk, TAP_RESERVE, copylen, |