xref: /dpdk/lib/graph/graph_pcap.c (revision 93998f3c5f22747e4f2c5e8714fa5cbe6c9d1574)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(C) 2023 Marvell International Ltd.
3  */
4 
5 #include <errno.h>
6 #include <pwd.h>
7 #include <stdlib.h>
8 #include <unistd.h>
9 
10 #include <rte_ethdev.h>
11 #include <rte_mbuf.h>
12 #include <rte_pcapng.h>
13 
14 #include "rte_graph_worker.h"
15 
16 #include "graph_pcap_private.h"
17 
18 #define GRAPH_PCAP_BUF_SZ	128
19 #define GRAPH_PCAP_NUM_PACKETS	1024
20 #define GRAPH_PCAP_PKT_POOL	"graph_pcap_pkt_pool"
21 #define GRAPH_PCAP_FILE_NAME	"dpdk_graph_pcap_capture_XXXXXX.pcapng"
22 
23 /* For multi-process, packets are captured in separate files. */
24 static rte_pcapng_t *pcapng_fd;
25 static bool pcap_enable;
26 struct rte_mempool *pkt_mp;
27 
28 void
29 graph_pcap_enable(bool val)
30 {
31 	pcap_enable = val;
32 }
33 
34 int
35 graph_pcap_is_enable(void)
36 {
37 	return pcap_enable;
38 }
39 
40 void
41 graph_pcap_exit(struct rte_graph *graph)
42 {
43 	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
44 		rte_mempool_free(pkt_mp);
45 
46 	if (pcapng_fd) {
47 		rte_pcapng_close(pcapng_fd);
48 		pcapng_fd = NULL;
49 	}
50 
51 	/* Disable pcap. */
52 	graph->pcap_enable = 0;
53 	graph_pcap_enable(0);
54 }
55 
56 static int
57 graph_pcap_default_path_get(char **dir_path)
58 {
59 	struct passwd *pwd;
60 	char *home_dir;
61 
62 	/* First check for shell environment variable */
63 	home_dir = getenv("HOME");
64 	if (home_dir == NULL) {
65 		graph_warn("Home env not preset.");
66 		/* Fallback to password file entry */
67 		pwd = getpwuid(getuid());
68 		if (pwd == NULL)
69 			return -EINVAL;
70 
71 		home_dir = pwd->pw_dir;
72 	}
73 
74 	/* Append default pcap file to directory */
75 	if (asprintf(dir_path, "%s/%s", home_dir, GRAPH_PCAP_FILE_NAME) == -1)
76 		return -ENOMEM;
77 
78 	return 0;
79 }
80 
81 int
82 graph_pcap_file_open(const char *filename)
83 {
84 	int fd, ret;
85 	uint16_t portid;
86 	char file_name[RTE_GRAPH_PCAP_FILE_SZ];
87 	char *pcap_dir;
88 
89 	if (pcapng_fd)
90 		goto done;
91 
92 	if (!filename || filename[0] == '\0') {
93 		if (graph_pcap_default_path_get(&pcap_dir) < 0)
94 			return -1;
95 		snprintf(file_name, RTE_GRAPH_PCAP_FILE_SZ, "%s", pcap_dir);
96 		free(pcap_dir);
97 	} else {
98 		snprintf(file_name, RTE_GRAPH_PCAP_FILE_SZ, "%s_XXXXXX.pcapng",
99 			 filename);
100 	}
101 
102 	fd = mkstemps(file_name, strlen(".pcapng"));
103 	if (fd < 0) {
104 		graph_err("mkstemps() failure");
105 		return -1;
106 	}
107 
108 	graph_info("pcap filename: %s", file_name);
109 
110 	/* Open a capture file */
111 	pcapng_fd = rte_pcapng_fdopen(fd, NULL, NULL, "Graph pcap tracer",
112 				      NULL);
113 	if (pcapng_fd == NULL) {
114 		graph_err("Graph rte_pcapng_fdopen failed.");
115 		goto error;
116 	}
117 
118 	/* Add the configured interfaces as possible capture ports */
119 	RTE_ETH_FOREACH_DEV(portid) {
120 		ret = rte_pcapng_add_interface(pcapng_fd, portid,
121 					       NULL, NULL, NULL);
122 		if (ret < 0) {
123 			graph_err("Graph rte_pcapng_add_interface port %u failed: %d",
124 				  portid, ret);
125 			goto error;
126 		}
127 	}
128 
129 done:
130 	return 0;
131 error:
132 	if (pcapng_fd != NULL) {
133 		rte_pcapng_close(pcapng_fd);
134 		pcapng_fd = NULL;
135 	}
136 	close(fd);
137 	return -1;
138 }
139 
140 int
141 graph_pcap_mp_init(void)
142 {
143 	pkt_mp = rte_mempool_lookup(GRAPH_PCAP_PKT_POOL);
144 	if (pkt_mp)
145 		goto done;
146 
147 	/* Make a pool for cloned packets */
148 	pkt_mp = rte_pktmbuf_pool_create_by_ops(GRAPH_PCAP_PKT_POOL,
149 			IOV_MAX + RTE_GRAPH_BURST_SIZE,	0, 0,
150 			rte_pcapng_mbuf_size(RTE_MBUF_DEFAULT_BUF_SIZE),
151 			SOCKET_ID_ANY, "ring_mp_mc");
152 	if (pkt_mp == NULL) {
153 		graph_err("Cannot create mempool for graph pcap capture.");
154 		return -1;
155 	}
156 
157 done:
158 	return 0;
159 }
160 
161 int
162 graph_pcap_init(struct graph *graph)
163 {
164 	struct rte_graph *graph_data = graph->graph;
165 
166 	if (graph_pcap_file_open(graph->pcap_filename) < 0)
167 		goto error;
168 
169 	if (graph_pcap_mp_init() < 0)
170 		goto error;
171 
172 	/* User configured number of packets to capture. */
173 	if (graph->num_pkt_to_capture)
174 		graph_data->nb_pkt_to_capture = graph->num_pkt_to_capture;
175 	else
176 		graph_data->nb_pkt_to_capture = GRAPH_PCAP_NUM_PACKETS;
177 
178 	/* All good. Now populate data for secondary process. */
179 	rte_strscpy(graph_data->pcap_filename, graph->pcap_filename, RTE_GRAPH_PCAP_FILE_SZ);
180 	graph_data->pcap_enable = 1;
181 
182 	return 0;
183 
184 error:
185 	graph_pcap_exit(graph_data);
186 	graph_pcap_enable(0);
187 	graph_err("Graph pcap initialization failed. Disabling pcap trace.");
188 	return -1;
189 }
190 
191 uint16_t
192 graph_pcap_dispatch(struct rte_graph *graph,
193 			      struct rte_node *node, void **objs,
194 			      uint16_t nb_objs)
195 {
196 	struct rte_mbuf *mbuf_clones[RTE_GRAPH_BURST_SIZE];
197 	char buffer[GRAPH_PCAP_BUF_SZ];
198 	uint64_t i, num_packets;
199 	struct rte_mbuf *mbuf;
200 	ssize_t len;
201 
202 	if (!nb_objs || (graph->nb_pkt_captured >= graph->nb_pkt_to_capture))
203 		goto done;
204 
205 	num_packets = graph->nb_pkt_to_capture - graph->nb_pkt_captured;
206 	/* nb_objs will never be greater than RTE_GRAPH_BURST_SIZE */
207 	if (num_packets > nb_objs)
208 		num_packets = nb_objs;
209 
210 	snprintf(buffer, GRAPH_PCAP_BUF_SZ, "%s: %s", graph->name, node->name);
211 
212 	for (i = 0; i < num_packets; i++) {
213 		struct rte_mbuf *mc;
214 		mbuf = (struct rte_mbuf *)objs[i];
215 
216 		mc = rte_pcapng_copy(mbuf->port, 0, mbuf, pkt_mp, mbuf->pkt_len,
217 				     0, buffer);
218 		if (mc == NULL)
219 			break;
220 
221 		mbuf_clones[i] = mc;
222 	}
223 
224 	/* write it to capture file */
225 	len = rte_pcapng_write_packets(pcapng_fd, mbuf_clones, i);
226 	rte_pktmbuf_free_bulk(mbuf_clones, i);
227 	if (len <= 0)
228 		goto done;
229 
230 	graph->nb_pkt_captured += i;
231 
232 done:
233 	return node->original_process(graph, node, objs, nb_objs);
234 }
235