diff options
| -rw-r--r-- | drivers/net/macvtap.c | 3 | ||||
| -rw-r--r-- | drivers/net/tun.c | 6 | ||||
| -rw-r--r-- | include/net/ipv6.h | 2 | ||||
| -rw-r--r-- | net/ipv6/output_core.c | 38 |
4 files changed, 48 insertions, 1 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 052d1832d3fb..4abd98efdc34 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -17,6 +17,7 @@ #include <linux/idr.h> #include <linux/fs.h> +#include <net/ipv6.h> #include <net/net_namespace.h> #include <net/rtnetlink.h> #include <net/sock.h> @@ -566,6 +567,8 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb, break; case VIRTIO_NET_HDR_GSO_UDP: gso_type = SKB_GSO_UDP; + if (skb->protocol == htons(ETH_P_IPV6)) + ipv6_proxy_select_ident(skb); break; default: return -EINVAL; diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 10636cbd3807..495830a8ee28 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -65,6 +65,7 @@ #include <linux/nsproxy.h> #include <linux/virtio_net.h> #include <linux/rcupdate.h> +#include <net/ipv6.h> #include <net/net_namespace.h> #include <net/netns/generic.h> #include <net/rtnetlink.h> @@ -1103,6 +1104,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, break; } + skb_reset_network_header(skb); + if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { pr_debug("GSO!\n"); switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { @@ -1114,6 +1117,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, break; case VIRTIO_NET_HDR_GSO_UDP: skb_shinfo(skb)->gso_type = SKB_GSO_UDP; + if (skb->protocol == htons(ETH_P_IPV6)) + ipv6_proxy_select_ident(skb); break; default: tun->dev->stats.rx_frame_errors++; @@ -1143,7 +1148,6 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; } - skb_reset_network_header(skb); skb_probe_transport_header(skb, 0); rxhash = skb_get_rxhash(skb); diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 6b4956e4408f..ea97c94fbc7d 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -661,6 +661,8 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr)); } +extern void ipv6_proxy_select_ident(struct sk_buff *skb); + extern int ip6_dst_hoplimit(struct dst_entry *dst); /* diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c index 798eb0f79078..4bd870af05d6 100644 --- a/net/ipv6/output_core.c +++ b/net/ipv6/output_core.c @@ -3,10 +3,48 @@ * not configured or static. These functions are needed by GSO/GRO implementation. */ #include <linux/export.h> +#include <linux/random.h> +#include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_fib.h> #include <net/addrconf.h> +/* This function exists only for tap drivers that must support broken + * clients requesting UFO without specifying an IPv6 fragment ID. + * + * This is similar to ipv6_select_ident() but we use an independent hash + * seed to limit information leakage. + * + * The network header must be set before calling this. + */ +void ipv6_proxy_select_ident(struct sk_buff *skb) +{ + static u32 ip6_proxy_idents_hashrnd __read_mostly; + struct in6_addr buf[2]; + struct in6_addr *addrs; + static bool done = false; + u32 hash, id; + + addrs = skb_header_pointer(skb, + skb_network_offset(skb) + + offsetof(struct ipv6hdr, saddr), + sizeof(buf), buf); + if (!addrs) + return; + + if (!done) { + get_random_bytes(&ip6_proxy_idents_hashrnd, + sizeof(ip6_proxy_idents_hashrnd)); + done = true; + } + + hash = __ipv6_addr_jhash(&addrs[1], ip6_proxy_idents_hashrnd); + hash = __ipv6_addr_jhash(&addrs[0], hash); + + id = ip_idents_reserve(hash, 1); + skb_shinfo(skb)->ip6_frag_id = htonl(id); +} +EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident); int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) { |