From a7ae1992248e5cf9dc5bd35695ab846d27efe15f Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 18 Nov 2011 02:20:04 +0000 Subject: [PATCH] ipv6: Remove all uses of LL_ALLOCATED_SPACE ipv6: Remove all uses of LL_ALLOCATED_SPACE The macro LL_ALLOCATED_SPACE was ill-conceived. It applies the alignment to the sum of needed_headroom and needed_tailroom. As the amount that is then reserved for head room is needed_headroom with alignment, this means that the tail room left may be too small. This patch replaces all uses of LL_ALLOCATED_SPACE in net/ipv6 with the macro LL_RESERVED_SPACE and direct reference to needed_tailroom. This also fixes the problem with needed_headroom changing between allocating the skb and reserving the head room. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 8 ++++++-- net/ipv6/mcast.c | 12 ++++++++---- net/ipv6/ndisc.c | 13 +++++++++---- net/ipv6/raw.c | 6 ++++-- 4 files changed, 27 insertions(+), 12 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 84d0bd5cac9..68ef97f353b 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -631,6 +631,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) struct ipv6hdr *tmp_hdr; struct frag_hdr *fh; unsigned int mtu, hlen, left, len; + int hroom, troom; __be32 frag_id = 0; int ptr, offset = 0, err=0; u8 *prevhdr, nexthdr = 0; @@ -797,6 +798,8 @@ slow_path: */ *prevhdr = NEXTHDR_FRAGMENT; + hroom = LL_RESERVED_SPACE(rt->dst.dev); + troom = rt->dst.dev->needed_tailroom; /* * Keep copying data until we run out. @@ -815,7 +818,8 @@ slow_path: * Allocate buffer. */ - if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->dst.dev), GFP_ATOMIC)) == NULL) { + if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + + hroom + troom, GFP_ATOMIC)) == NULL) { NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); @@ -828,7 +832,7 @@ slow_path: */ ip6_copy_metadata(frag, skb); - skb_reserve(frag, LL_RESERVED_SPACE(rt->dst.dev)); + skb_reserve(frag, hroom); skb_put(frag, len + hlen + sizeof(struct frag_hdr)); skb_reset_network_header(frag); fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index ee7839f4d6e..7b94bebb73b 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -1343,13 +1343,15 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size) struct mld2_report *pmr; struct in6_addr addr_buf; const struct in6_addr *saddr; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; int err; u8 ra[8] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT, 2, 0, 0, IPV6_TLV_PADN, 0 }; /* we assume size > sizeof(ra) here */ - size += LL_ALLOCATED_SPACE(dev); + size += hlen + tlen; /* limit our allocations to order-0 page */ size = min_t(int, size, SKB_MAX_ORDER(0, 0)); skb = sock_alloc_send_skb(sk, size, 1, &err); @@ -1357,7 +1359,7 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size) if (!skb) return NULL; - skb_reserve(skb, LL_RESERVED_SPACE(dev)); + skb_reserve(skb, hlen); if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) { /* : @@ -1723,6 +1725,8 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type) struct mld_msg *hdr; const struct in6_addr *snd_addr, *saddr; struct in6_addr addr_buf; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; int err, len, payload_len, full_len; u8 ra[8] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT, 2, 0, 0, @@ -1744,7 +1748,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type) IPSTATS_MIB_OUT, full_len); rcu_read_unlock(); - skb = sock_alloc_send_skb(sk, LL_ALLOCATED_SPACE(dev) + full_len, 1, &err); + skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err); if (skb == NULL) { rcu_read_lock(); @@ -1754,7 +1758,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type) return; } - skb_reserve(skb, LL_RESERVED_SPACE(dev)); + skb_reserve(skb, hlen); if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) { /* : diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 4a209822262..d699ddcad4c 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -446,6 +446,8 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev, struct sock *sk = net->ipv6.ndisc_sk; struct sk_buff *skb; struct icmp6hdr *hdr; + int hlen = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; int len; int err; u8 *opt; @@ -459,7 +461,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev, skb = sock_alloc_send_skb(sk, (MAX_HEADER + sizeof(struct ipv6hdr) + - len + LL_ALLOCATED_SPACE(dev)), + len + hlen + tlen), 1, &err); if (!skb) { ND_PRINTK0(KERN_ERR @@ -468,7 +470,7 @@ struct sk_buff *ndisc_build_skb(struct net_device *dev, return NULL; } - skb_reserve(skb, LL_RESERVED_SPACE(dev)); + skb_reserve(skb, hlen); ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); skb->transport_header = skb->tail; @@ -1533,6 +1535,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, struct inet6_dev *idev; struct flowi6 fl6; u8 *opt; + int hlen, tlen; int rd_len; int err; u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; @@ -1590,9 +1593,11 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, rd_len &= ~0x7; len += rd_len; + hlen = LL_RESERVED_SPACE(dev); + tlen = dev->needed_tailroom; buff = sock_alloc_send_skb(sk, (MAX_HEADER + sizeof(struct ipv6hdr) + - len + LL_ALLOCATED_SPACE(dev)), + len + hlen + tlen), 1, &err); if (buff == NULL) { ND_PRINTK0(KERN_ERR @@ -1601,7 +1606,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, goto release; } - skb_reserve(buff, LL_RESERVED_SPACE(dev)); + skb_reserve(buff, hlen); ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, IPPROTO_ICMPV6, len); diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 204f2e833f0..a1aa869a9ce 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -611,6 +611,8 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length, struct sk_buff *skb; int err; struct rt6_info *rt = (struct rt6_info *)*dstp; + int hlen = LL_RESERVED_SPACE(rt->dst.dev); + int tlen = rt->dst.dev->needed_tailroom; if (length > rt->dst.dev->mtu) { ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu); @@ -620,11 +622,11 @@ static int rawv6_send_hdrinc(struct sock *sk, void *from, int length, goto out; skb = sock_alloc_send_skb(sk, - length + LL_ALLOCATED_SPACE(rt->dst.dev) + 15, + length + hlen + tlen + 15, flags & MSG_DONTWAIT, &err); if (skb == NULL) goto error; - skb_reserve(skb, LL_RESERVED_SPACE(rt->dst.dev)); + skb_reserve(skb, hlen); skb->priority = sk->sk_priority; skb->mark = sk->sk_mark; -- 2.46.0