From c9af6db4c11ccc6c3e7f19bbc15d54023956f97c Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Mon, 11 Feb 2013 09:27:41 +0000 Subject: [PATCH] net: Fix possible wrong checksum generation. Patch cef401de7be8c4e (net: fix possible wrong checksum generation) fixed wrong checksum calculation but it broke TSO by defining new GSO type but not a netdev feature for that type. net_gso_ok() would not allow hardware checksum/segmentation offload of such packets without the feature. Following patch fixes TSO and wrong checksum. This patch uses same logic that Eric Dumazet used. Patch introduces new flag SKBTX_SHARED_FRAG if at least one frag can be modified by the user. but SKBTX_SHARED_FRAG flag is kept in skb shared info tx_flags rather than gso_type. tx_flags is better compared to gso_type since we can have skb with shared frag without gso packet. It does not link SHARED_FRAG to GSO, So there is no need to define netdev feature for this. Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- drivers/net/macvtap.c | 4 ++-- drivers/net/tun.c | 13 +++++-------- drivers/net/virtio_net.c | 13 +++++-------- include/linux/skbuff.h | 17 +++++++++-------- net/core/skbuff.c | 5 ++--- net/ipv4/af_inet.c | 1 - net/ipv4/ip_output.c | 1 + net/ipv4/tcp.c | 4 +--- net/ipv4/tcp_input.c | 4 ++-- net/ipv4/tcp_output.c | 4 ++-- net/ipv6/ip6_offload.c | 1 - 11 files changed, 29 insertions(+), 38 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index b181dfb..9724301 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -543,7 +543,6 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, skb->data_len += len; skb->len += len; skb->truesize += truesize; - skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG; atomic_add(truesize, &skb->sk->sk_wmem_alloc); while (len) { int off = base & ~PAGE_MASK; @@ -599,7 +598,7 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb, if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { skb_shinfo(skb)->gso_size = vnet_hdr->gso_size; - skb_shinfo(skb)->gso_type |= gso_type; + skb_shinfo(skb)->gso_type = gso_type; /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; @@ -743,6 +742,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, if (zerocopy) { skb_shinfo(skb)->destructor_arg = m->msg_control; skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; } if (vlan) macvlan_start_xmit(skb, vlan->dev); diff --git a/drivers/net/tun.c b/drivers/net/tun.c index b1038c0..b6f45c5 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1019,7 +1019,6 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, skb->data_len += len; skb->len += len; skb->truesize += truesize; - skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG; atomic_add(truesize, &skb->sk->sk_wmem_alloc); while (len) { int off = base & ~PAGE_MASK; @@ -1165,18 +1164,16 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { - unsigned short gso_type = 0; - pr_debug("GSO!\n"); switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: - gso_type = SKB_GSO_TCPV4; + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; break; case VIRTIO_NET_HDR_GSO_TCPV6: - gso_type = SKB_GSO_TCPV6; + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; break; case VIRTIO_NET_HDR_GSO_UDP: - gso_type = SKB_GSO_UDP; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP; break; default: tun->dev->stats.rx_frame_errors++; @@ -1185,10 +1182,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) - gso_type |= SKB_GSO_TCP_ECN; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; skb_shinfo(skb)->gso_size = gso.gso_size; - skb_shinfo(skb)->gso_type |= gso_type; if (skb_shinfo(skb)->gso_size == 0) { tun->dev->stats.rx_frame_errors++; kfree_skb(skb); @@ -1204,6 +1200,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, if (zerocopy) { skb_shinfo(skb)->destructor_arg = msg_control; skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; } skb_reset_network_header(skb); diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 381a2d8..192c91c 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -227,7 +227,7 @@ static void set_skb_frag(struct sk_buff *skb, struct page *page, skb->len += size; skb->truesize += PAGE_SIZE; skb_shinfo(skb)->nr_frags++; - skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG; + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; *len -= size; } @@ -387,18 +387,16 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) ntohs(skb->protocol), skb->len, skb->pkt_type); if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { - unsigned short gso_type = 0; - pr_debug("GSO!\n"); switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: - gso_type = SKB_GSO_TCPV4; + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; break; case VIRTIO_NET_HDR_GSO_UDP: - gso_type = SKB_GSO_UDP; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP; break; case VIRTIO_NET_HDR_GSO_TCPV6: - gso_type = SKB_GSO_TCPV6; + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; break; default: net_warn_ratelimited("%s: bad gso type %u.\n", @@ -407,7 +405,7 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) } if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) - gso_type |= SKB_GSO_TCP_ECN; + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; if (skb_shinfo(skb)->gso_size == 0) { @@ -415,7 +413,6 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len) goto frame_err; } - skb_shinfo(skb)->gso_type |= gso_type; /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; skb_shinfo(skb)->gso_segs = 0; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d7573c3..9da9952 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -230,6 +230,13 @@ enum { /* generate wifi status information (where possible) */ SKBTX_WIFI_STATUS = 1 << 4, + + /* This indicates at least one fragment might be overwritten + * (as in vmsplice(), sendfile() ...) + * If we need to compute a TX checksum, we'll need to copy + * all frags to avoid possible bad checksum + */ + SKBTX_SHARED_FRAG = 1 << 5, }; /* @@ -307,13 +314,6 @@ enum { SKB_GSO_TCPV6 = 1 << 4, SKB_GSO_FCOE = 1 << 5, - - /* This indicates at least one fragment might be overwritten - * (as in vmsplice(), sendfile() ...) - * If we need to compute a TX checksum, we'll need to copy - * all frags to avoid possible bad checksum - */ - SKB_GSO_SHARED_FRAG = 1 << 6, }; #if BITS_PER_LONG > 32 @@ -2220,7 +2220,8 @@ static inline int skb_linearize(struct sk_buff *skb) */ static inline bool skb_has_shared_frag(const struct sk_buff *skb) { - return skb_shinfo(skb)->gso_type & SKB_GSO_SHARED_FRAG; + return skb_is_nonlinear(skb) && + skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; } /** diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 21a22cc..6c1ad09 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2326,8 +2326,7 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) { int pos = skb_headlen(skb); - skb_shinfo(skb1)->gso_type = skb_shinfo(skb)->gso_type; - + skb_shinfo(skb)->tx_flags = skb_shinfo(skb1)->tx_flags & SKBTX_SHARED_FRAG; if (len < pos) /* Split line is inside header. */ skb_split_inside_header(skb, skb1, len, pos); else /* Second chunk has no header, nothing to copy. */ @@ -2833,7 +2832,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) skb_copy_from_linear_data_offset(skb, offset, skb_put(nskb, hsize), hsize); - skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type; + skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; while (pos < offset + len && i < nfrags) { *frag = skb_shinfo(skb)->frags[i]; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 1aec92b..e6e5d85 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1287,7 +1287,6 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, SKB_GSO_UDP | SKB_GSO_DODGY | SKB_GSO_TCP_ECN | - SKB_GSO_SHARED_FRAG | 0))) goto out; diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 3e98ed2..5e12dca 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -598,6 +598,7 @@ slow_path: /* for offloaded checksums cleanup checksum before fragmentation */ if ((skb->ip_summed == CHECKSUM_PARTIAL) && skb_checksum_help(skb)) goto fail; + iph = ip_hdr(skb); left = skb->len - hlen; /* Space per frame */ ptr = hlen; /* Where to start from */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 801b07b..1f0bedb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -897,8 +897,7 @@ new_segment: get_page(page); skb_fill_page_desc(skb, i, page, offset, copy); } - - skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG; + skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; skb->len += copy; skb->data_len += copy; @@ -3044,7 +3043,6 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, SKB_GSO_DODGY | SKB_GSO_TCP_ECN | SKB_GSO_TCPV6 | - SKB_GSO_SHARED_FRAG | 0) || !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))) goto out; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index d9bfaea..a759e19 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1239,13 +1239,13 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, */ if (!skb_shinfo(prev)->gso_size) { skb_shinfo(prev)->gso_size = mss; - skb_shinfo(prev)->gso_type |= sk->sk_gso_type; + skb_shinfo(prev)->gso_type = sk->sk_gso_type; } /* CHECKME: To clear or not to clear? Mimics normal skb currently */ if (skb_shinfo(skb)->gso_segs <= 1) { skb_shinfo(skb)->gso_size = 0; - skb_shinfo(skb)->gso_type &= SKB_GSO_SHARED_FRAG; + skb_shinfo(skb)->gso_type = 0; } /* Difference in this won't matter, both ACKed by the same cumul. ACK */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 564bf89..6182d90 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1133,7 +1133,6 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb, unsigned int mss_now) { - skb_shinfo(skb)->gso_type &= SKB_GSO_SHARED_FRAG; if (skb->len <= mss_now || !sk_can_gso(sk) || skb->ip_summed == CHECKSUM_NONE) { /* Avoid the costly divide in the normal @@ -1141,10 +1140,11 @@ static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb, */ skb_shinfo(skb)->gso_segs = 1; skb_shinfo(skb)->gso_size = 0; + skb_shinfo(skb)->gso_type = 0; } else { skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss_now); skb_shinfo(skb)->gso_size = mss_now; - skb_shinfo(skb)->gso_type |= sk->sk_gso_type; + skb_shinfo(skb)->gso_type = sk->sk_gso_type; } } diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index d141fc3..f26f0da 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -100,7 +100,6 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, SKB_GSO_DODGY | SKB_GSO_TCP_ECN | SKB_GSO_TCPV6 | - SKB_GSO_SHARED_FRAG | 0))) goto out; -- 2.7.4