xref: /aosp_15_r20/external/libnl/src/nl-pktloc-lookup.c (revision 4dc78e53d49367fa8e61b07018507c90983a077d)
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2010 Thomas Graf <[email protected]>
4  */
5 
6 #include "nl-default.h"
7 
8 #include <linux/tc_ematch/tc_em_cmp.h>
9 
10 #include <netlink/cli/utils.h>
11 #include <netlink/route/pktloc.h>
12 
print_usage(void)13 static void print_usage(void)
14 {
15 printf(
16 "Usage: nl-pktloc-lookup [OPTIONS] <name>\n"
17 "\n"
18 "OPTIONS\n"
19 " -h, --help                Show this help text.\n"
20 " -v, --version             Show versioning information.\n"
21 " -l, --list                List all packet location definitions.\n"
22 "     --u32=VALUE	    Print in iproute2's u32 selector style\n"
23 "\n"
24 "\n"
25 "EXAMPLE\n"
26 "   $ nl-pktloc-lookup ip.dst\n"
27 "   $ nl-pktloc-lookup --list\n"
28 "\n"
29 );
30 	exit(0);
31 }
32 
33 static const char *align_txt[] = {
34 	[TCF_EM_ALIGN_U8] = "u8",
35 	[TCF_EM_ALIGN_U16] = "u16",
36 	[TCF_EM_ALIGN_U32] = "u32"
37 };
38 
39 static uint32_t align_mask[] = {
40 	[TCF_EM_ALIGN_U8] = 0xff,
41 	[TCF_EM_ALIGN_U16] = 0xffff,
42 	[TCF_EM_ALIGN_U32] = 0xffffffff,
43 };
44 
45 static const char *layer_txt[] = {
46 	[TCF_LAYER_LINK] = "eth",
47 	[TCF_LAYER_NETWORK] = "ip",
48 	[TCF_LAYER_TRANSPORT] = "tcp"
49 };
50 
get_align_txt(struct rtnl_pktloc * loc,char buf[static16])51 static const char *get_align_txt(struct rtnl_pktloc *loc, char buf[static 16])
52 {
53 	if (loc->align < _NL_N_ELEMENTS(align_txt))
54 		return align_txt[loc->align];
55 
56 	snprintf(buf, 16, "%u", loc->align);
57 	return buf;
58 }
59 
dump_u32_style(struct rtnl_pktloc * loc,uint32_t value)60 static void dump_u32_style(struct rtnl_pktloc *loc, uint32_t value)
61 {
62 	char buf[16];
63 
64 	if (loc->align > 4)
65 		nl_cli_fatal(EINVAL, "u32 only supports alignments u8|u16|u32.");
66 
67 	if (loc->layer == TCF_LAYER_LINK)
68 		nl_cli_fatal(EINVAL, "u32 does not support link "
69 				"layer locations.");
70 
71 	if (loc->shift > 0)
72 		nl_cli_fatal(EINVAL, "u32 does not support shifting.");
73 
74 	printf("%s %x %x at %s%u\n", get_align_txt(loc, buf), value,
75 	       loc->mask ? loc->mask :
76 				 (loc->align < _NL_N_ELEMENTS(align_mask) ?
77 				    align_mask[loc->align] :
78 					  0),
79 	       loc->layer == TCF_LAYER_TRANSPORT ? "nexthdr+" : "",
80 	       loc->offset);
81 }
82 
dump_loc(struct rtnl_pktloc * loc)83 static void dump_loc(struct rtnl_pktloc *loc)
84 {
85 	char buf[16];
86 
87 	printf("%s = %s at %s+%u & %#x >> %u\n", loc->name,
88 	       get_align_txt(loc, buf),
89 	       loc->layer < _NL_N_ELEMENTS(layer_txt) ? layer_txt[loc->layer] :
90 							      "???",
91 	       loc->offset, loc->mask, loc->shift);
92 }
93 
list_cb(struct rtnl_pktloc * loc,void * arg)94 static void list_cb(struct rtnl_pktloc *loc, void *arg)
95 {
96 	char buf[16];
97 
98 	printf("%-26s %-5s %3s+%-4u %#-10x %-8u %u\n", loc->name,
99 	       get_align_txt(loc, buf),
100 	       loc->layer < _NL_N_ELEMENTS(layer_txt) ? layer_txt[loc->layer] :
101 							     "???",
102 	       loc->offset, loc->mask, loc->shift, loc->refcnt);
103 }
104 
do_list(void)105 static void do_list(void)
106 {
107 	printf(
108 "name                      align  offset  mask     shift    refcnt\n");
109 	printf("---------------------------------------------------------\n");
110 
111 	rtnl_pktloc_foreach(&list_cb, NULL);
112 }
113 
main(int argc,char * argv[])114 int main(int argc, char *argv[])
115 {
116 	struct rtnl_pktloc *loc;
117 	int err, ustyle = 0;
118 	uint32_t uvalue = 0;
119 
120 	for (;;) {
121 		int c, optidx = 0;
122 		enum {
123 			ARG_U32 = 257,
124 		};
125 		static struct option long_opts[] = {
126 			{ "help", 0, 0, 'h' },
127 			{ "version", 0, 0, 'v' },
128 			{ "list", 0, 0, 'l' },
129 			{ "u32", 1, 0, ARG_U32 },
130 			{ 0, 0, 0, 0 }
131 		};
132 
133 		c = getopt_long(argc, argv, "hvl", long_opts, &optidx);
134 		if (c == -1)
135 			break;
136 
137 		switch (c) {
138 		case 'h': print_usage(); break;
139 		case 'v': nl_cli_print_version(); break;
140 		case 'l': do_list(); exit(0);
141 		case ARG_U32:
142 			ustyle = 1;
143 			uvalue = nl_cli_parse_u32(optarg);
144 			break;
145 		}
146 	}
147 
148 	if (optind >= argc)
149 		print_usage();
150 
151 	if ((err = rtnl_pktloc_lookup(argv[optind++], &loc)) < 0)
152 		nl_cli_fatal(err, "Unable to lookup packet location: %s",
153 			nl_geterror(err));
154 
155 	if (ustyle)
156 		dump_u32_style(loc, uvalue);
157 	else
158 		dump_loc(loc);
159 
160 	return 0;
161 }
162