xref: /dpdk/examples/ipsec-secgw/ipip.h (revision 27d822e88e61fa74f30a9239fc5bb24daaae7f59)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2016 Intel Corporation
3  */
4 
5 #ifndef __IPIP_H__
6 #define __IPIP_H__
7 
8 #include <stdint.h>
9 #include <netinet/in.h>
10 #include <netinet/ip.h>
11 #include <netinet/ip6.h>
12 
13 #include <rte_mbuf.h>
14 
15 static inline void *
ipip_outbound(struct rte_mbuf * m,uint32_t offset,uint32_t is_ipv6,struct ip_addr * src,struct ip_addr * dst)16 ipip_outbound(struct rte_mbuf *m, uint32_t offset, uint32_t is_ipv6,
17 		struct ip_addr *src,  struct ip_addr *dst)
18 {
19 	struct ip *inip4, *outip4;
20 	struct ip6_hdr *inip6, *outip6;
21 	uint8_t ds_ecn;
22 
23 	inip4 = rte_pktmbuf_mtod(m, struct ip *);
24 
25 	RTE_ASSERT(inip4->ip_v == IPVERSION || inip4->ip_v == IP6_VERSION);
26 
27 	if (inip4->ip_v == IPVERSION) {
28 		/* XXX This should be done by the forwarding engine instead */
29 		inip4->ip_ttl -= 1;
30 		if (inip4->ip_sum >= rte_cpu_to_be_16(0xffff - 0x100))
31 			inip4->ip_sum += rte_cpu_to_be_16(0x100) + 1;
32 		else
33 			inip4->ip_sum += rte_cpu_to_be_16(0x100);
34 		ds_ecn = inip4->ip_tos;
35 	} else {
36 		inip6 = (struct ip6_hdr *)inip4;
37 		/* XXX This should be done by the forwarding engine instead */
38 		inip6->ip6_hops -= 1;
39 		ds_ecn = ntohl(inip6->ip6_flow) >> 20;
40 	}
41 
42 	if (is_ipv6) {
43 		offset += sizeof(struct ip6_hdr);
44 		outip6 = (struct ip6_hdr *)rte_pktmbuf_prepend(m, offset);
45 
46 		RTE_ASSERT(outip6 != NULL);
47 
48 		/* Per RFC4301 5.1.2.1 */
49 		outip6->ip6_flow = htonl(IP6_VERSION << 28 | ds_ecn << 20);
50 		outip6->ip6_plen = htons(rte_pktmbuf_data_len(m) -
51 					 sizeof(struct ip6_hdr));
52 
53 		outip6->ip6_nxt = IPPROTO_ESP;
54 		outip6->ip6_hops = IPDEFTTL;
55 
56 		memcpy(&outip6->ip6_src.s6_addr, src, 16);
57 		memcpy(&outip6->ip6_dst.s6_addr, dst, 16);
58 
59 		return outip6;
60 	}
61 
62 	offset += sizeof(struct ip);
63 	outip4 = (struct ip *)rte_pktmbuf_prepend(m, offset);
64 
65 	RTE_ASSERT(outip4 != NULL);
66 
67 	/* Per RFC4301 5.1.2.1 */
68 	outip4->ip_v = IPVERSION;
69 	outip4->ip_hl = 5;
70 	outip4->ip_tos = ds_ecn;
71 	outip4->ip_len = htons(rte_pktmbuf_data_len(m));
72 
73 	outip4->ip_id = 0;
74 	outip4->ip_off = 0;
75 
76 	outip4->ip_ttl = IPDEFTTL;
77 	outip4->ip_p = IPPROTO_ESP;
78 
79 	outip4->ip_src.s_addr = src->ip.ip4;
80 	outip4->ip_dst.s_addr = dst->ip.ip4;
81 	m->packet_type &= ~RTE_PTYPE_L4_MASK;
82 	return outip4;
83 }
84 
85 static inline struct ip *
ip4ip_outbound(struct rte_mbuf * m,uint32_t offset,struct ip_addr * src,struct ip_addr * dst)86 ip4ip_outbound(struct rte_mbuf *m, uint32_t offset,
87 		struct ip_addr *src,  struct ip_addr *dst)
88 {
89 	return ipip_outbound(m, offset, 0, src, dst);
90 }
91 
92 static inline struct ip6_hdr *
ip6ip_outbound(struct rte_mbuf * m,uint32_t offset,struct ip_addr * src,struct ip_addr * dst)93 ip6ip_outbound(struct rte_mbuf *m, uint32_t offset,
94 		struct ip_addr *src,  struct ip_addr *dst)
95 {
96 	return ipip_outbound(m, offset, 1, src, dst);
97 }
98 
99 static inline void
ip4_ecn_setup(struct ip * ip4)100 ip4_ecn_setup(struct ip *ip4)
101 {
102 	if (ip4->ip_tos & IPTOS_ECN_MASK) {
103 		unsigned long sum;
104 		uint8_t old;
105 
106 		old = ip4->ip_tos;
107 		ip4->ip_tos |= IPTOS_ECN_CE;
108 		sum = old + (~(*(uint8_t *)&ip4->ip_tos) & 0xff);
109 		sum += rte_be_to_cpu_16(ip4->ip_sum);
110 		sum = (sum & 0xffff) + (sum >> 16);
111 		ip4->ip_sum = rte_cpu_to_be_16(sum + (sum >> 16));
112 	}
113 }
114 
115 static inline void
ip6_ecn_setup(struct ip6_hdr * ip6)116 ip6_ecn_setup(struct ip6_hdr *ip6)
117 {
118 	if ((ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK)
119 		ip6->ip6_flow = htonl(ntohl(ip6->ip6_flow) |
120 					(IPTOS_ECN_CE << 20));
121 }
122 
123 static inline void
ipip_inbound(struct rte_mbuf * m,uint32_t offset)124 ipip_inbound(struct rte_mbuf *m, uint32_t offset)
125 {
126 	struct ip *inip4, *outip4;
127 	struct ip6_hdr *inip6, *outip6;
128 	uint32_t ip_len, set_ecn;
129 
130 	outip4 = rte_pktmbuf_mtod(m, struct ip*);
131 
132 	RTE_ASSERT(outip4->ip_v == IPVERSION || outip4->ip_v == IP6_VERSION);
133 
134 	if (outip4->ip_v == IPVERSION) {
135 		ip_len = sizeof(struct ip);
136 		set_ecn = ((outip4->ip_tos & IPTOS_ECN_CE) == IPTOS_ECN_CE);
137 	} else {
138 		outip6 = (struct ip6_hdr *)outip4;
139 		ip_len = sizeof(struct ip6_hdr);
140 		set_ecn = ntohl(outip6->ip6_flow) >> 20;
141 		set_ecn = ((set_ecn & IPTOS_ECN_CE) == IPTOS_ECN_CE);
142 	}
143 
144 	inip4 = (struct ip *)rte_pktmbuf_adj(m, offset + ip_len);
145 	RTE_ASSERT(inip4->ip_v == IPVERSION || inip4->ip_v == IP6_VERSION);
146 
147 	/* Check packet is still bigger than IP header (inner) */
148 	RTE_ASSERT(rte_pktmbuf_pkt_len(m) > ip_len);
149 
150 	/* RFC4301 5.1.2.1 Note 6 */
151 	if (inip4->ip_v == IPVERSION) {
152 		if (set_ecn)
153 			ip4_ecn_setup(inip4);
154 		/* XXX This should be done by the forwarding engine instead */
155 		inip4->ip_ttl -= 1;
156 		if (inip4->ip_sum >= rte_cpu_to_be_16(0xffff - 0x100))
157 			inip4->ip_sum += rte_cpu_to_be_16(0x100) + 1;
158 		else
159 			inip4->ip_sum += rte_cpu_to_be_16(0x100);
160 		m->packet_type &= ~RTE_PTYPE_L4_MASK;
161 		if (inip4->ip_p == IPPROTO_UDP)
162 			m->packet_type |= RTE_PTYPE_L4_UDP;
163 		else if (inip4->ip_p == IPPROTO_TCP)
164 			m->packet_type |= RTE_PTYPE_L4_TCP;
165 	} else {
166 		inip6 = (struct ip6_hdr *)inip4;
167 		if (set_ecn)
168 			ip6_ecn_setup(inip6);
169 		/* XXX This should be done by the forwarding engine instead */
170 		inip6->ip6_hops -= 1;
171 	}
172 }
173 
174 #endif /* __IPIP_H__ */
175