[PATCH net-next v8] net: openvswitch: IPv6: Add IPv6 extension header support
From: Toms Atteka <hidden>
Date: 2021-11-24 19:33:54
This change adds a new OpenFlow field OFPXMT_OFB_IPV6_EXTHDR and packets can be filtered using ipv6_ext flag. Signed-off-by: Toms Atteka <redacted> --- include/uapi/linux/openvswitch.h | 6 ++ net/openvswitch/flow.c | 140 +++++++++++++++++++++++++++++++ net/openvswitch/flow.h | 14 ++++ net/openvswitch/flow_netlink.c | 26 +++++- 4 files changed, 184 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index a87b44cd5590..43790f07e4a2 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h@@ -342,6 +342,7 @@ enum ovs_key_attr { OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4, /* struct ovs_key_ct_tuple_ipv4 */ OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6, /* struct ovs_key_ct_tuple_ipv6 */ OVS_KEY_ATTR_NSH, /* Nested set of ovs_nsh_key_* */ + OVS_KEY_ATTR_IPV6_EXTHDRS, /* struct ovs_key_ipv6_exthdr */ #ifdef __KERNEL__ OVS_KEY_ATTR_TUNNEL_INFO, /* struct ip_tunnel_info */
@@ -421,6 +422,11 @@ struct ovs_key_ipv6 { __u8 ipv6_frag; /* One of OVS_FRAG_TYPE_*. */ }; +/* separate structure to support backward compatibility with older user space */ +struct ovs_key_ipv6_exthdrs { + __u16 hdrs; +}; + struct ovs_key_tcp { __be16 tcp_src; __be16 tcp_dst;
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 9d375e74b607..28acb40437ca 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c@@ -239,6 +239,144 @@ static bool icmphdr_ok(struct sk_buff *skb) sizeof(struct icmphdr)); } +/** + * get_ipv6_ext_hdrs() - Parses packet and sets IPv6 extension header flags. + * + * @skb: buffer where extension header data starts in packet + * @nh: ipv6 header + * @ext_hdrs: flags are stored here + * + * OFPIEH12_UNREP is set if more than one of a given IPv6 extension header + * is unexpectedly encountered. (Two destination options headers may be + * expected and would not cause this bit to be set.) + * + * OFPIEH12_UNSEQ is set if IPv6 extension headers were not in the order + * preferred (but not required) by RFC 2460: + * + * When more than one extension header is used in the same packet, it is + * recommended that those headers appear in the following order: + * IPv6 header + * Hop-by-Hop Options header + * Destination Options header + * Routing header + * Fragment header + * Authentication header + * Encapsulating Security Payload header + * Destination Options header + * upper-layer header + */ +static void get_ipv6_ext_hdrs(struct sk_buff *skb, struct ipv6hdr *nh, + u16 *ext_hdrs) +{ + u8 next_type = nh->nexthdr; + unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr); + int dest_options_header_count = 0; + + *ext_hdrs = 0; + + while (ipv6_ext_hdr(next_type)) { + struct ipv6_opt_hdr _hdr, *hp; + + switch (next_type) { + case IPPROTO_NONE: + *ext_hdrs |= OFPIEH12_NONEXT; + /* stop parsing */ + return; + + case IPPROTO_ESP: + if (*ext_hdrs & OFPIEH12_ESP) + *ext_hdrs |= OFPIEH12_UNREP; + if ((*ext_hdrs & ~(OFPIEH12_HOP | OFPIEH12_DEST | + OFPIEH12_ROUTER | IPPROTO_FRAGMENT | + OFPIEH12_AUTH | OFPIEH12_UNREP)) || + dest_options_header_count >= 2) { + *ext_hdrs |= OFPIEH12_UNSEQ; + } + *ext_hdrs |= OFPIEH12_ESP; + break; + + case IPPROTO_AH: + if (*ext_hdrs & OFPIEH12_AUTH) + *ext_hdrs |= OFPIEH12_UNREP; + if ((*ext_hdrs & + ~(OFPIEH12_HOP | OFPIEH12_DEST | OFPIEH12_ROUTER | + IPPROTO_FRAGMENT | OFPIEH12_UNREP)) || + dest_options_header_count >= 2) { + *ext_hdrs |= OFPIEH12_UNSEQ; + } + *ext_hdrs |= OFPIEH12_AUTH; + break; + + case IPPROTO_DSTOPTS: + if (dest_options_header_count == 0) { + if (*ext_hdrs & + ~(OFPIEH12_HOP | OFPIEH12_UNREP)) + *ext_hdrs |= OFPIEH12_UNSEQ; + *ext_hdrs |= OFPIEH12_DEST; + } else if (dest_options_header_count == 1) { + if (*ext_hdrs & + ~(OFPIEH12_HOP | OFPIEH12_DEST | + OFPIEH12_ROUTER | OFPIEH12_FRAG | + OFPIEH12_AUTH | OFPIEH12_ESP | + OFPIEH12_UNREP)) { + *ext_hdrs |= OFPIEH12_UNSEQ; + } + } else { + *ext_hdrs |= OFPIEH12_UNREP; + } + dest_options_header_count++; + break; + + case IPPROTO_FRAGMENT: + if (*ext_hdrs & OFPIEH12_FRAG) + *ext_hdrs |= OFPIEH12_UNREP; + if ((*ext_hdrs & ~(OFPIEH12_HOP | + OFPIEH12_DEST | + OFPIEH12_ROUTER | + OFPIEH12_UNREP)) || + dest_options_header_count >= 2) { + *ext_hdrs |= OFPIEH12_UNSEQ; + } + *ext_hdrs |= OFPIEH12_FRAG; + break; + + case IPPROTO_ROUTING: + if (*ext_hdrs & OFPIEH12_ROUTER) + *ext_hdrs |= OFPIEH12_UNREP; + if ((*ext_hdrs & ~(OFPIEH12_HOP | + OFPIEH12_DEST | + OFPIEH12_UNREP)) || + dest_options_header_count >= 2) { + *ext_hdrs |= OFPIEH12_UNSEQ; + } + *ext_hdrs |= OFPIEH12_ROUTER; + break; + + case IPPROTO_HOPOPTS: + if (*ext_hdrs & OFPIEH12_HOP) + *ext_hdrs |= OFPIEH12_UNREP; + /* OFPIEH12_HOP is set to 1 if a hop-by-hop IPv6 + * extension header is present as the first + * extension header in the packet. + */ + if (*ext_hdrs == 0) + *ext_hdrs |= OFPIEH12_HOP; + else + *ext_hdrs |= OFPIEH12_UNSEQ; + break; + + default: + return; + } + + hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); + if (!hp) + break; + next_type = hp->nexthdr; + start += ipv6_optlen(hp); + }; +} + static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) { unsigned short frag_off;
@@ -254,6 +392,8 @@ static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) nh = ipv6_hdr(skb); + get_ipv6_ext_hdrs(skb, nh, &key->ipv6.exthdrs); + key->ip.proto = NEXTHDR_NONE; key->ip.tos = ipv6_get_dsfield(nh); key->ip.ttl = nh->hop_limit;
diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
index 758a8c77f736..073ab73ffeaa 100644
--- a/net/openvswitch/flow.h
+++ b/net/openvswitch/flow.h@@ -32,6 +32,19 @@ enum sw_flow_mac_proto { #define SW_FLOW_KEY_INVALID 0x80 #define MPLS_LABEL_DEPTH 3 +/* Bit definitions for IPv6 Extension Header pseudo-field. */ +enum ofp12_ipv6exthdr_flags { + OFPIEH12_NONEXT = 1 << 0, /* "No next header" encountered. */ + OFPIEH12_ESP = 1 << 1, /* Encrypted Sec Payload header present. */ + OFPIEH12_AUTH = 1 << 2, /* Authentication header present. */ + OFPIEH12_DEST = 1 << 3, /* 1 or 2 dest headers present. */ + OFPIEH12_FRAG = 1 << 4, /* Fragment header present. */ + OFPIEH12_ROUTER = 1 << 5, /* Router header present. */ + OFPIEH12_HOP = 1 << 6, /* Hop-by-hop header present. */ + OFPIEH12_UNREP = 1 << 7, /* Unexpected repeats encountered. */ + OFPIEH12_UNSEQ = 1 << 8 /* Unexpected sequencing encountered. */ +}; + /* Store options at the end of the array if they are less than the * maximum size. This allows us to get the benefits of variable length * matching for small options.
@@ -121,6 +134,7 @@ struct sw_flow_key { struct in6_addr dst; /* IPv6 destination address. */ } addr; __be32 label; /* IPv6 flow label. */ + u16 exthdrs; /* IPv6 extension header flags */ union { struct { struct in6_addr src;
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 65c2e3458ff5..0aeaf28594ce 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c@@ -344,7 +344,7 @@ size_t ovs_key_attr_size(void) /* Whenever adding new OVS_KEY_ FIELDS, we should consider * updating this function. */ - BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 29); + BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 30); return nla_total_size(4) /* OVS_KEY_ATTR_PRIORITY */ + nla_total_size(0) /* OVS_KEY_ATTR_TUNNEL */
@@ -367,7 +367,8 @@ size_t ovs_key_attr_size(void) + nla_total_size(2) /* OVS_KEY_ATTR_ETHERTYPE */ + nla_total_size(40) /* OVS_KEY_ATTR_IPV6 */ + nla_total_size(2) /* OVS_KEY_ATTR_ICMPV6 */ - + nla_total_size(28); /* OVS_KEY_ATTR_ND */ + + nla_total_size(28) /* OVS_KEY_ATTR_ND */ + + nla_total_size(2); /* OVS_KEY_ATTR_IPV6_EXTHDRS */ } static const struct ovs_len_tbl ovs_vxlan_ext_key_lens[OVS_VXLAN_EXT_MAX + 1] = {
@@ -435,6 +436,8 @@ static const struct ovs_len_tbl ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = { .len = sizeof(struct ovs_key_ct_tuple_ipv6) }, [OVS_KEY_ATTR_NSH] = { .len = OVS_ATTR_NESTED, .next = ovs_nsh_key_attr_lens, }, + [OVS_KEY_ATTR_IPV6_EXTHDRS] = { + .len = sizeof(struct ovs_key_ipv6_exthdrs) }, }; static bool check_attr_len(unsigned int attr_len, unsigned int expected_len)
@@ -1595,6 +1598,17 @@ static int ovs_key_from_nlattrs(struct net *net, struct sw_flow_match *match, attrs &= ~(1 << OVS_KEY_ATTR_IPV6); } + if (attrs & (1ULL << OVS_KEY_ATTR_IPV6_EXTHDRS)) { + const struct ovs_key_ipv6_exthdrs *ipv6_exthdrs_key; + + ipv6_exthdrs_key = nla_data(a[OVS_KEY_ATTR_IPV6_EXTHDRS]); + + SW_FLOW_KEY_PUT(match, ipv6.exthdrs, + ipv6_exthdrs_key->hdrs, is_mask); + + attrs &= ~(1ULL << OVS_KEY_ATTR_IPV6_EXTHDRS); + } + if (attrs & (1 << OVS_KEY_ATTR_ARP)) { const struct ovs_key_arp *arp_key;
@@ -2097,6 +2111,7 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey, ipv4_key->ipv4_frag = output->ip.frag; } else if (swkey->eth.type == htons(ETH_P_IPV6)) { struct ovs_key_ipv6 *ipv6_key; + struct ovs_key_ipv6_exthdrs *ipv6_exthdrs_key; nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6, sizeof(*ipv6_key)); if (!nla)
@@ -2111,6 +2126,13 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey, ipv6_key->ipv6_tclass = output->ip.tos; ipv6_key->ipv6_hlimit = output->ip.ttl; ipv6_key->ipv6_frag = output->ip.frag; + + nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6_EXTHDRS, + sizeof(*ipv6_exthdrs_key)); + if (!nla) + goto nla_put_failure; + ipv6_exthdrs_key = nla_data(nla); + ipv6_exthdrs_key->hdrs = output->ipv6.exthdrs; } else if (swkey->eth.type == htons(ETH_P_NSH)) { if (nsh_key_to_nlattr(&output->nsh, is_mask, skb)) goto nla_put_failure;
--
2.25.1