xref: /dpdk/lib/net/rte_net.h (revision 719834a6849e1daf4a70ff7742bbcc3ae7e25607)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2016 6WIND S.A.
3  */
4 
5 #ifndef _RTE_NET_PTYPE_H_
6 #define _RTE_NET_PTYPE_H_
7 
8 #include <rte_ip.h>
9 #include <rte_udp.h>
10 #include <rte_tcp.h>
11 
12 #ifdef __cplusplus
13 extern "C" {
14 #endif
15 
16 /**
17  * Structure containing header lengths associated to a packet, filled
18  * by rte_net_get_ptype().
19  */
20 struct rte_net_hdr_lens {
21 	uint8_t l2_len;
22 	uint8_t inner_l2_len;
23 	uint16_t l3_len;
24 	uint16_t inner_l3_len;
25 	uint16_t tunnel_len;
26 	uint8_t l4_len;
27 	uint8_t inner_l4_len;
28 };
29 
30 /**
31  * Skip IPv6 header extensions.
32  *
33  * This function skips all IPv6 extensions, returning size of
34  * complete header including options and final protocol value.
35  *
36  * @param proto
37  *   Protocol field of IPv6 header.
38  * @param m
39  *   The packet mbuf to be parsed.
40  * @param off
41  *   On input, must contain the offset to the first byte following
42  *   IPv6 header, on output, contains offset to the first byte
43  *   of next layer (after any IPv6 extension header)
44  * @param frag
45  *   Contains 1 in output if packet is an IPv6 fragment.
46  * @return
47  *   Protocol that follows IPv6 header.
48  *   -1 if an error occurs during mbuf parsing.
49  */
50 int
51 rte_net_skip_ip6_ext(uint16_t proto, const struct rte_mbuf *m, uint32_t *off,
52 	int *frag);
53 
54 /**
55  * Parse an Ethernet packet to get its packet type.
56  *
57  * This function parses the network headers in mbuf data and return its
58  * packet type.
59  *
60  * If it is provided by the user, it also fills a rte_net_hdr_lens
61  * structure that contains the lengths of the parsed network
62  * headers. Each length field is valid only if the associated packet
63  * type is set. For instance, hdr_lens->l2_len is valid only if
64  * (retval & RTE_PTYPE_L2_MASK) != RTE_PTYPE_UNKNOWN.
65  *
66  * Supported packet types are:
67  *   L2: Ether, Vlan, QinQ
68  *   L3: IPv4, IPv6
69  *   L4: TCP, UDP, SCTP
70  *   Tunnels: IPv4, IPv6, Gre, Nvgre
71  *
72  * @param m
73  *   The packet mbuf to be parsed.
74  * @param hdr_lens
75  *   A pointer to a structure where the header lengths will be returned,
76  *   or NULL.
77  * @param layers
78  *   List of layers to parse. The function will stop at the first
79  *   empty layer. Examples:
80  *   - To parse all known layers, use RTE_PTYPE_ALL_MASK.
81  *   - To parse only L2 and L3, use RTE_PTYPE_L2_MASK | RTE_PTYPE_L3_MASK
82  * @return
83  *   The packet type of the packet.
84  */
85 uint32_t rte_net_get_ptype(const struct rte_mbuf *m,
86 	struct rte_net_hdr_lens *hdr_lens, uint32_t layers);
87 
88 /**
89  * Prepare pseudo header checksum
90  *
91  * This function prepares pseudo header checksum for TSO and non-TSO tcp/udp in
92  * provided mbufs packet data and based on the requested offload flags.
93  *
94  * - for non-TSO tcp/udp packets full pseudo-header checksum is counted and set
95  *   in packet data,
96  * - for TSO the IP payload length is not included in pseudo header.
97  *
98  * This function expects that used headers are in the first data segment of
99  * mbuf, are not fragmented and can be safely modified.
100  *
101  * @param m
102  *   The packet mbuf to be fixed.
103  * @param ol_flags
104  *   TX offloads flags to use with this packet.
105  * @return
106  *   0 if checksum is initialized properly
107  */
108 static inline int
109 rte_net_intel_cksum_flags_prepare(struct rte_mbuf *m, uint64_t ol_flags)
110 {
111 	const uint64_t inner_requests = RTE_MBUF_F_TX_IP_CKSUM | RTE_MBUF_F_TX_L4_MASK |
112 		RTE_MBUF_F_TX_TCP_SEG | RTE_MBUF_F_TX_UDP_SEG;
113 	const uint64_t outer_requests = RTE_MBUF_F_TX_OUTER_IP_CKSUM |
114 		RTE_MBUF_F_TX_OUTER_UDP_CKSUM;
115 	/* Initialise ipv4_hdr to avoid false positive compiler warnings. */
116 	struct rte_ipv4_hdr *ipv4_hdr = NULL;
117 	struct rte_ipv6_hdr *ipv6_hdr;
118 	struct rte_tcp_hdr *tcp_hdr;
119 	struct rte_udp_hdr *udp_hdr;
120 	uint64_t inner_l3_offset = m->l2_len;
121 
122 	/*
123 	 * Does packet set any of available offloads?
124 	 * Mainly it is required to avoid fragmented headers check if
125 	 * no offloads are requested.
126 	 */
127 	if (!(ol_flags & (inner_requests | outer_requests)))
128 		return 0;
129 
130 	if (ol_flags & (RTE_MBUF_F_TX_OUTER_IPV4 | RTE_MBUF_F_TX_OUTER_IPV6)) {
131 		inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
132 		/*
133 		 * prepare outer IPv4 header checksum by setting it to 0,
134 		 * in order to be computed by hardware NICs.
135 		 */
136 		if (ol_flags & RTE_MBUF_F_TX_OUTER_IP_CKSUM) {
137 			ipv4_hdr = rte_pktmbuf_mtod_offset(m,
138 					struct rte_ipv4_hdr *, m->outer_l2_len);
139 			ipv4_hdr->hdr_checksum = 0;
140 		}
141 		if (ol_flags & RTE_MBUF_F_TX_OUTER_UDP_CKSUM || ol_flags & inner_requests) {
142 			if (ol_flags & RTE_MBUF_F_TX_OUTER_IPV4) {
143 				ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv4_hdr *,
144 					m->outer_l2_len);
145 				udp_hdr = (struct rte_udp_hdr *)((char *)ipv4_hdr +
146 					m->outer_l3_len);
147 				if (ol_flags & RTE_MBUF_F_TX_OUTER_UDP_CKSUM)
148 					udp_hdr->dgram_cksum = rte_ipv4_phdr_cksum(ipv4_hdr,
149 						m->ol_flags);
150 				else if (ipv4_hdr->next_proto_id == IPPROTO_UDP)
151 					udp_hdr->dgram_cksum = 0;
152 			} else {
153 				ipv6_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv6_hdr *,
154 					m->outer_l2_len);
155 				udp_hdr = rte_pktmbuf_mtod_offset(m, struct rte_udp_hdr *,
156 					 m->outer_l2_len + m->outer_l3_len);
157 				if (ol_flags & RTE_MBUF_F_TX_OUTER_UDP_CKSUM)
158 					udp_hdr->dgram_cksum = rte_ipv6_phdr_cksum(ipv6_hdr,
159 						m->ol_flags);
160 				else if (ipv6_hdr->proto == IPPROTO_UDP)
161 					udp_hdr->dgram_cksum = 0;
162 			}
163 		}
164 	}
165 
166 	/*
167 	 * Check if headers are fragmented.
168 	 * The check could be less strict depending on which offloads are
169 	 * requested and headers to be used, but let's keep it simple.
170 	 */
171 	if (unlikely(rte_pktmbuf_data_len(m) <
172 		     inner_l3_offset + m->l3_len + m->l4_len))
173 		return -ENOTSUP;
174 
175 	if (ol_flags & RTE_MBUF_F_TX_IPV4) {
176 		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv4_hdr *,
177 				inner_l3_offset);
178 
179 		if (ol_flags & RTE_MBUF_F_TX_IP_CKSUM)
180 			ipv4_hdr->hdr_checksum = 0;
181 	}
182 
183 	if ((ol_flags & RTE_MBUF_F_TX_L4_MASK) == RTE_MBUF_F_TX_UDP_CKSUM ||
184 			(ol_flags & RTE_MBUF_F_TX_UDP_SEG)) {
185 		if (ol_flags & RTE_MBUF_F_TX_IPV4) {
186 			udp_hdr = (struct rte_udp_hdr *)((char *)ipv4_hdr +
187 					m->l3_len);
188 			udp_hdr->dgram_cksum = rte_ipv4_phdr_cksum(ipv4_hdr,
189 					ol_flags);
190 		} else {
191 			ipv6_hdr = rte_pktmbuf_mtod_offset(m,
192 				struct rte_ipv6_hdr *, inner_l3_offset);
193 			/* non-TSO udp */
194 			udp_hdr = rte_pktmbuf_mtod_offset(m,
195 					struct rte_udp_hdr *,
196 					inner_l3_offset + m->l3_len);
197 			udp_hdr->dgram_cksum = rte_ipv6_phdr_cksum(ipv6_hdr,
198 					ol_flags);
199 		}
200 	} else if ((ol_flags & RTE_MBUF_F_TX_L4_MASK) == RTE_MBUF_F_TX_TCP_CKSUM ||
201 			(ol_flags & RTE_MBUF_F_TX_TCP_SEG)) {
202 		if (ol_flags & RTE_MBUF_F_TX_IPV4) {
203 			/* non-TSO tcp or TSO */
204 			tcp_hdr = (struct rte_tcp_hdr *)((char *)ipv4_hdr +
205 					m->l3_len);
206 			tcp_hdr->cksum = rte_ipv4_phdr_cksum(ipv4_hdr,
207 					ol_flags);
208 		} else {
209 			ipv6_hdr = rte_pktmbuf_mtod_offset(m,
210 				struct rte_ipv6_hdr *, inner_l3_offset);
211 			/* non-TSO tcp or TSO */
212 			tcp_hdr = rte_pktmbuf_mtod_offset(m,
213 					struct rte_tcp_hdr *,
214 					inner_l3_offset + m->l3_len);
215 			tcp_hdr->cksum = rte_ipv6_phdr_cksum(ipv6_hdr,
216 					ol_flags);
217 		}
218 	}
219 
220 	return 0;
221 }
222 
223 /**
224  * Prepare pseudo header checksum
225  *
226  * This function prepares pseudo header checksum for TSO and non-TSO tcp/udp in
227  * provided mbufs packet data.
228  *
229  * - for non-TSO tcp/udp packets full pseudo-header checksum is counted and set
230  *   in packet data,
231  * - for TSO the IP payload length is not included in pseudo header.
232  *
233  * This function expects that used headers are in the first data segment of
234  * mbuf, are not fragmented and can be safely modified.
235  *
236  * @param m
237  *   The packet mbuf to be fixed.
238  * @return
239  *   0 if checksum is initialized properly
240  */
241 static inline int
242 rte_net_intel_cksum_prepare(struct rte_mbuf *m)
243 {
244 	return rte_net_intel_cksum_flags_prepare(m, m->ol_flags);
245 }
246 
247 #ifdef __cplusplus
248 }
249 #endif
250 
251 
252 #endif /* _RTE_NET_PTYPE_H_ */
253