xref: /dpdk/lib/gso/gso_common.c (revision e15331dd269da07f7d70a0c7c6b06bd07949c4d1)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2017 Intel Corporation
3  */
4 
5 #include <stdbool.h>
6 #include <errno.h>
7 
8 #include <rte_memcpy.h>
9 
10 #include "gso_common.h"
11 
12 static inline void
hdr_segment_init(struct rte_mbuf * hdr_segment,struct rte_mbuf * pkt,uint16_t pkt_hdr_offset)13 hdr_segment_init(struct rte_mbuf *hdr_segment, struct rte_mbuf *pkt,
14 		uint16_t pkt_hdr_offset)
15 {
16 	/* Copy MBUF metadata */
17 	hdr_segment->nb_segs = 1;
18 	hdr_segment->port = pkt->port;
19 	hdr_segment->ol_flags = pkt->ol_flags;
20 	hdr_segment->packet_type = pkt->packet_type;
21 	hdr_segment->pkt_len = pkt_hdr_offset;
22 	hdr_segment->data_len = pkt_hdr_offset;
23 	hdr_segment->tx_offload = pkt->tx_offload;
24 
25 	/* Copy the packet header */
26 	rte_memcpy(rte_pktmbuf_mtod(hdr_segment, char *),
27 			rte_pktmbuf_mtod(pkt, char *),
28 			pkt_hdr_offset);
29 }
30 
31 static inline void
free_gso_segment(struct rte_mbuf ** pkts,uint16_t nb_pkts)32 free_gso_segment(struct rte_mbuf **pkts, uint16_t nb_pkts)
33 {
34 	uint16_t i;
35 
36 	for (i = 0; i < nb_pkts; i++)
37 		rte_pktmbuf_free(pkts[i]);
38 }
39 
40 int
gso_do_segment(struct rte_mbuf * pkt,uint16_t pkt_hdr_offset,uint16_t pyld_unit_size,struct rte_mempool * direct_pool,struct rte_mempool * indirect_pool,struct rte_mbuf ** pkts_out,uint16_t nb_pkts_out)41 gso_do_segment(struct rte_mbuf *pkt,
42 		uint16_t pkt_hdr_offset,
43 		uint16_t pyld_unit_size,
44 		struct rte_mempool *direct_pool,
45 		struct rte_mempool *indirect_pool,
46 		struct rte_mbuf **pkts_out,
47 		uint16_t nb_pkts_out)
48 {
49 	struct rte_mbuf *pkt_in;
50 	struct rte_mbuf *hdr_segment, *pyld_segment, *prev_segment;
51 	uint16_t pkt_in_data_pos, segment_bytes_remaining;
52 	uint16_t pyld_len, nb_segs;
53 	bool more_in_pkt, more_out_segs;
54 
55 	pkt_in = pkt;
56 	nb_segs = 0;
57 	more_in_pkt = 1;
58 	pkt_in_data_pos = pkt_hdr_offset;
59 
60 	while (more_in_pkt) {
61 		if (unlikely(nb_segs >= nb_pkts_out)) {
62 			free_gso_segment(pkts_out, nb_segs);
63 			return -EINVAL;
64 		}
65 
66 		/* Allocate a direct MBUF */
67 		hdr_segment = rte_pktmbuf_alloc(direct_pool);
68 		if (unlikely(hdr_segment == NULL)) {
69 			free_gso_segment(pkts_out, nb_segs);
70 			return -ENOMEM;
71 		}
72 		/* Fill the packet header */
73 		hdr_segment_init(hdr_segment, pkt, pkt_hdr_offset);
74 
75 		prev_segment = hdr_segment;
76 		segment_bytes_remaining = pyld_unit_size;
77 		more_out_segs = 1;
78 
79 		while (more_out_segs && more_in_pkt) {
80 			/* Allocate an indirect MBUF */
81 			pyld_segment = rte_pktmbuf_alloc(indirect_pool);
82 			if (unlikely(pyld_segment == NULL)) {
83 				rte_pktmbuf_free(hdr_segment);
84 				free_gso_segment(pkts_out, nb_segs);
85 				return -ENOMEM;
86 			}
87 			/* Attach to current MBUF segment of pkt */
88 			rte_pktmbuf_attach(pyld_segment, pkt_in);
89 
90 			prev_segment->next = pyld_segment;
91 			prev_segment = pyld_segment;
92 
93 			pyld_len = segment_bytes_remaining;
94 			if (pyld_len + pkt_in_data_pos > pkt_in->data_len)
95 				pyld_len = pkt_in->data_len - pkt_in_data_pos;
96 
97 			pyld_segment->data_off = pkt_in_data_pos +
98 				pkt_in->data_off;
99 			pyld_segment->data_len = pyld_len;
100 
101 			/* Update header segment */
102 			hdr_segment->pkt_len += pyld_len;
103 			hdr_segment->nb_segs++;
104 
105 			pkt_in_data_pos += pyld_len;
106 			segment_bytes_remaining -= pyld_len;
107 
108 			/* Finish processing a MBUF segment of pkt */
109 			if (pkt_in_data_pos == pkt_in->data_len) {
110 				pkt_in = pkt_in->next;
111 				pkt_in_data_pos = 0;
112 				if (pkt_in == NULL)
113 					more_in_pkt = 0;
114 			}
115 
116 			/* Finish generating a GSO segment */
117 			if (segment_bytes_remaining == 0)
118 				more_out_segs = 0;
119 		}
120 		pkts_out[nb_segs++] = hdr_segment;
121 	}
122 	return nb_segs;
123 }
124