1 /*
2 * m_csum.c checksum updating action
3 *
4 * This program is free software; you can distribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Gregoire Baron <baronchon@n7mm.org>
10 */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <unistd.h>
16
17 #include <linux/tc_act/tc_csum.h>
18
19 #include "utils.h"
20 #include "tc_util.h"
21
22 static void
explain(void)23 explain(void)
24 {
25 fprintf(stderr, "Usage: ... csum <UPDATE>\n"
26 "Where: UPDATE := <TARGET> [<UPDATE>]\n"
27 " TARGET := { ip4h | icmp | igmp | tcp | udp | udplite | sctp | <SWEETS> }\n"
28 " SWEETS := { and | or | \'+\' }\n");
29 }
30
31 static void
usage(void)32 usage(void)
33 {
34 explain();
35 exit(-1);
36 }
37
38 static int
parse_csum_args(int * argc_p,char *** argv_p,struct tc_csum * sel)39 parse_csum_args(int *argc_p, char ***argv_p, struct tc_csum *sel)
40 {
41 int argc = *argc_p;
42 char **argv = *argv_p;
43
44 if (argc <= 0)
45 return -1;
46
47 while (argc > 0) {
48 if ((matches(*argv, "iph") == 0) ||
49 (matches(*argv, "ip4h") == 0) ||
50 (matches(*argv, "ipv4h") == 0))
51 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_IPV4HDR;
52
53 else if (matches(*argv, "icmp") == 0)
54 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_ICMP;
55
56 else if (matches(*argv, "igmp") == 0)
57 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_IGMP;
58
59 else if (matches(*argv, "tcp") == 0)
60 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_TCP;
61
62 else if (matches(*argv, "udp") == 0)
63 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_UDP;
64
65 else if (matches(*argv, "udplite") == 0)
66 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_UDPLITE;
67
68 else if (matches(*argv, "sctp") == 0)
69 sel->update_flags |= TCA_CSUM_UPDATE_FLAG_SCTP;
70
71 else if ((matches(*argv, "and") == 0) ||
72 (matches(*argv, "or") == 0) ||
73 (matches(*argv, "+") == 0))
74 ; /* just ignore: ... csum iph and tcp or udp */
75 else
76 break;
77 argc--;
78 argv++;
79 }
80
81 *argc_p = argc;
82 *argv_p = argv;
83
84 return 0;
85 }
86
87 static int
parse_csum(struct action_util * a,int * argc_p,char *** argv_p,int tca_id,struct nlmsghdr * n)88 parse_csum(struct action_util *a, int *argc_p,
89 char ***argv_p, int tca_id, struct nlmsghdr *n)
90 {
91 struct tc_csum sel = {};
92
93 int argc = *argc_p;
94 char **argv = *argv_p;
95 int ok = 0;
96 struct rtattr *tail;
97
98 while (argc > 0) {
99 if (matches(*argv, "csum") == 0) {
100 NEXT_ARG();
101 if (parse_csum_args(&argc, &argv, &sel)) {
102 fprintf(stderr, "Illegal csum construct (%s)\n",
103 *argv);
104 explain();
105 return -1;
106 }
107 ok++;
108 continue;
109 } else if (matches(*argv, "help") == 0) {
110 usage();
111 } else {
112 break;
113 }
114 }
115
116 if (!ok) {
117 explain();
118 return -1;
119 }
120
121 if (sel.update_flags == 0) {
122 fprintf(stderr, "Illegal csum construct, empty <UPDATE> list\n");
123 return -1;
124 }
125
126 parse_action_control_dflt(&argc, &argv, &sel.action, false, TC_ACT_OK);
127
128 if (argc) {
129 if (matches(*argv, "index") == 0) {
130 NEXT_ARG();
131 if (get_u32(&sel.index, *argv, 10)) {
132 fprintf(stderr, "Illegal \"index\" (%s) <csum>\n",
133 *argv);
134 return -1;
135 }
136 argc--;
137 argv++;
138 }
139 }
140
141 tail = NLMSG_TAIL(n);
142 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
143 addattr_l(n, MAX_MSG, TCA_CSUM_PARMS, &sel, sizeof(sel));
144 tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
145
146 *argc_p = argc;
147 *argv_p = argv;
148
149 return 0;
150 }
151
152 static int
print_csum(struct action_util * au,FILE * f,struct rtattr * arg)153 print_csum(struct action_util *au, FILE *f, struct rtattr *arg)
154 {
155 struct tc_csum *sel;
156
157 struct rtattr *tb[TCA_CSUM_MAX + 1];
158
159 char *uflag_1 = "";
160 char *uflag_2 = "";
161 char *uflag_3 = "";
162 char *uflag_4 = "";
163 char *uflag_5 = "";
164 char *uflag_6 = "";
165 char *uflag_7 = "";
166
167 int uflag_count = 0;
168
169 if (arg == NULL)
170 return -1;
171
172 parse_rtattr_nested(tb, TCA_CSUM_MAX, arg);
173
174 if (tb[TCA_CSUM_PARMS] == NULL) {
175 fprintf(f, "[NULL csum parameters]");
176 return -1;
177 }
178 sel = RTA_DATA(tb[TCA_CSUM_PARMS]);
179
180 if (sel->update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
181 uflag_1 = "iph";
182 uflag_count++;
183 }
184 #define CSUM_UFLAG_BUFFER(flag_buffer, flag_value, flag_string) \
185 do { \
186 if (sel->update_flags & flag_value) { \
187 flag_buffer = uflag_count > 0 ? \
188 ", " flag_string : flag_string; \
189 uflag_count++; \
190 } \
191 } while (0)
192 CSUM_UFLAG_BUFFER(uflag_2, TCA_CSUM_UPDATE_FLAG_ICMP, "icmp");
193 CSUM_UFLAG_BUFFER(uflag_3, TCA_CSUM_UPDATE_FLAG_IGMP, "igmp");
194 CSUM_UFLAG_BUFFER(uflag_4, TCA_CSUM_UPDATE_FLAG_TCP, "tcp");
195 CSUM_UFLAG_BUFFER(uflag_5, TCA_CSUM_UPDATE_FLAG_UDP, "udp");
196 CSUM_UFLAG_BUFFER(uflag_6, TCA_CSUM_UPDATE_FLAG_UDPLITE, "udplite");
197 CSUM_UFLAG_BUFFER(uflag_7, TCA_CSUM_UPDATE_FLAG_SCTP, "sctp");
198 if (!uflag_count) {
199 uflag_1 = "?empty";
200 }
201
202 fprintf(f, "csum (%s%s%s%s%s%s%s) ",
203 uflag_1, uflag_2, uflag_3,
204 uflag_4, uflag_5, uflag_6, uflag_7);
205 print_action_control(f, "action ", sel->action, "\n");
206 fprintf(f, "\tindex %u ref %d bind %d", sel->index, sel->refcnt,
207 sel->bindcnt);
208
209 if (show_stats) {
210 if (tb[TCA_CSUM_TM]) {
211 struct tcf_t *tm = RTA_DATA(tb[TCA_CSUM_TM]);
212
213 print_tm(f, tm);
214 }
215 }
216 fprintf(f, "\n");
217
218 return 0;
219 }
220
221 struct action_util csum_action_util = {
222 .id = "csum",
223 .parse_aopt = parse_csum,
224 .print_aopt = print_csum,
225 };
226