mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 16:16:56 +07:00
3de33e1ba0
A packet length of exactly IPV6_MAXPLEN is allowed, we should
refuse parsing options only if the size is 64KiB or more.
While at it, remove one extra variable and one assignment which
were also introduced by the commit that introduced the size
check. Checking the sum 'offset + len' and only later adding
'len' to 'offset' doesn't provide any advantage over directly
summing to 'offset' and checking it.
Fixes: 6399f1fae4
("ipv6: avoid overflow of offset in ip6_find_1stfragopt")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
181 lines
4.3 KiB
C
181 lines
4.3 KiB
C
/*
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* IPv6 library code, needed by static components when full IPv6 support is
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* not configured or static. These functions are needed by GSO/GRO implementation.
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*/
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#include <linux/export.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <net/ip6_fib.h>
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#include <net/addrconf.h>
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#include <net/secure_seq.h>
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#include <linux/netfilter.h>
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static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
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const struct in6_addr *dst,
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const struct in6_addr *src)
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{
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u32 hash, id;
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hash = __ipv6_addr_jhash(dst, hashrnd);
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hash = __ipv6_addr_jhash(src, hash);
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hash ^= net_hash_mix(net);
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/* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
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* set the hight order instead thus minimizing possible future
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* collisions.
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*/
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id = ip_idents_reserve(hash, 1);
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if (unlikely(!id))
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id = 1 << 31;
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return id;
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}
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/* This function exists only for tap drivers that must support broken
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* clients requesting UFO without specifying an IPv6 fragment ID.
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*
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* This is similar to ipv6_select_ident() but we use an independent hash
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* seed to limit information leakage.
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*
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* The network header must be set before calling this.
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*/
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void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
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{
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static u32 ip6_proxy_idents_hashrnd __read_mostly;
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struct in6_addr buf[2];
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struct in6_addr *addrs;
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u32 id;
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addrs = skb_header_pointer(skb,
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skb_network_offset(skb) +
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offsetof(struct ipv6hdr, saddr),
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sizeof(buf), buf);
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if (!addrs)
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return;
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net_get_random_once(&ip6_proxy_idents_hashrnd,
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sizeof(ip6_proxy_idents_hashrnd));
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id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
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&addrs[1], &addrs[0]);
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skb_shinfo(skb)->ip6_frag_id = htonl(id);
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}
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EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
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__be32 ipv6_select_ident(struct net *net,
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const struct in6_addr *daddr,
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const struct in6_addr *saddr)
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{
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static u32 ip6_idents_hashrnd __read_mostly;
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u32 id;
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net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
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id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
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return htonl(id);
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}
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EXPORT_SYMBOL(ipv6_select_ident);
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int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
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{
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unsigned int offset = sizeof(struct ipv6hdr);
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unsigned int packet_len = skb_tail_pointer(skb) -
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skb_network_header(skb);
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int found_rhdr = 0;
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*nexthdr = &ipv6_hdr(skb)->nexthdr;
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while (offset <= packet_len) {
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struct ipv6_opt_hdr *exthdr;
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switch (**nexthdr) {
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case NEXTHDR_HOP:
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break;
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case NEXTHDR_ROUTING:
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found_rhdr = 1;
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break;
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case NEXTHDR_DEST:
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
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break;
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#endif
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if (found_rhdr)
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return offset;
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break;
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default:
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return offset;
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}
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if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
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return -EINVAL;
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exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
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offset);
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offset += ipv6_optlen(exthdr);
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if (offset > IPV6_MAXPLEN)
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return -EINVAL;
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*nexthdr = &exthdr->nexthdr;
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}
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return -EINVAL;
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}
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EXPORT_SYMBOL(ip6_find_1stfragopt);
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#if IS_ENABLED(CONFIG_IPV6)
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int ip6_dst_hoplimit(struct dst_entry *dst)
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{
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int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
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if (hoplimit == 0) {
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struct net_device *dev = dst->dev;
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struct inet6_dev *idev;
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rcu_read_lock();
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idev = __in6_dev_get(dev);
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if (idev)
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hoplimit = idev->cnf.hop_limit;
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else
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hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
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rcu_read_unlock();
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}
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return hoplimit;
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}
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EXPORT_SYMBOL(ip6_dst_hoplimit);
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#endif
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int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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int len;
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len = skb->len - sizeof(struct ipv6hdr);
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if (len > IPV6_MAXPLEN)
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len = 0;
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ipv6_hdr(skb)->payload_len = htons(len);
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IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
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/* if egress device is enslaved to an L3 master device pass the
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* skb to its handler for processing
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*/
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skb = l3mdev_ip6_out(sk, skb);
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if (unlikely(!skb))
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return 0;
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skb->protocol = htons(ETH_P_IPV6);
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return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
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net, sk, skb, NULL, skb_dst(skb)->dev,
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dst_output);
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}
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EXPORT_SYMBOL_GPL(__ip6_local_out);
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int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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int err;
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err = __ip6_local_out(net, sk, skb);
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if (likely(err == 1))
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err = dst_output(net, sk, skb);
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return err;
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}
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EXPORT_SYMBOL_GPL(ip6_local_out);
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