1 /* Shared library add-on to iptables to add TOS target support. */
2 #include <stdio.h>
3 #include <string.h>
4 #include <stdlib.h>
5 #include <getopt.h>
6
7 #include <iptables.h>
8 #include <linux/netfilter_ipv4/ip_tables.h>
9 #include <linux/netfilter_ipv4/ipt_TOS.h>
10
11 struct tosinfo {
12 struct ipt_entry_target t;
13 struct ipt_tos_target_info tos;
14 };
15
16 /* TOS names and values. */
17 static
18 struct TOS_value
19 {
20 unsigned char TOS;
21 const char *name;
22 } TOS_values[] = {
23 { IPTOS_LOWDELAY, "Minimize-Delay" },
24 { IPTOS_THROUGHPUT, "Maximize-Throughput" },
25 { IPTOS_RELIABILITY, "Maximize-Reliability" },
26 { IPTOS_MINCOST, "Minimize-Cost" },
27 { IPTOS_NORMALSVC, "Normal-Service" },
28 };
29
30 /* Function which prints out usage message. */
31 static void
help(void)32 help(void)
33 {
34 unsigned int i;
35
36 printf(
37 "TOS target v%s options:\n"
38 " --set-tos value Set Type of Service field to one of the\n"
39 " following numeric or descriptive values:\n",
40 IPTABLES_VERSION);
41
42 for (i = 0; i < sizeof(TOS_values)/sizeof(struct TOS_value);i++)
43 printf(" %s %u (0x%02x)\n",
44 TOS_values[i].name,
45 TOS_values[i].TOS,
46 TOS_values[i].TOS);
47 fputc('\n', stdout);
48 }
49
50 static struct option opts[] = {
51 { "set-tos", 1, 0, '1' },
52 { 0 }
53 };
54
55 /* Initialize the target. */
56 static void
init(struct ipt_entry_target * t,unsigned int * nfcache)57 init(struct ipt_entry_target *t, unsigned int *nfcache)
58 {
59 }
60
61 static void
parse_tos(const char * s,struct ipt_tos_target_info * info)62 parse_tos(const char *s, struct ipt_tos_target_info *info)
63 {
64 unsigned int i, tos;
65
66 if (string_to_number(s, 0, 255, &tos) != -1) {
67 if (tos == IPTOS_LOWDELAY
68 || tos == IPTOS_THROUGHPUT
69 || tos == IPTOS_RELIABILITY
70 || tos == IPTOS_MINCOST
71 || tos == IPTOS_NORMALSVC) {
72 info->tos = (u_int8_t )tos;
73 return;
74 }
75 } else {
76 for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
77 if (strcasecmp(s,TOS_values[i].name) == 0) {
78 info->tos = TOS_values[i].TOS;
79 return;
80 }
81 }
82 exit_error(PARAMETER_PROBLEM, "Bad TOS value `%s'", s);
83 }
84
85 /* Function which parses command options; returns true if it
86 ate an option */
87 static int
parse(int c,char ** argv,int invert,unsigned int * flags,const struct ipt_entry * entry,struct ipt_entry_target ** target)88 parse(int c, char **argv, int invert, unsigned int *flags,
89 const struct ipt_entry *entry,
90 struct ipt_entry_target **target)
91 {
92 struct ipt_tos_target_info *tosinfo
93 = (struct ipt_tos_target_info *)(*target)->data;
94
95 switch (c) {
96 case '1':
97 if (*flags)
98 exit_error(PARAMETER_PROBLEM,
99 "TOS target: Cant specify --set-tos twice");
100 parse_tos(optarg, tosinfo);
101 *flags = 1;
102 break;
103
104 default:
105 return 0;
106 }
107
108 return 1;
109 }
110
111 static void
final_check(unsigned int flags)112 final_check(unsigned int flags)
113 {
114 if (!flags)
115 exit_error(PARAMETER_PROBLEM,
116 "TOS target: Parameter --set-tos is required");
117 }
118
119 static void
print_tos(u_int8_t tos,int numeric)120 print_tos(u_int8_t tos, int numeric)
121 {
122 unsigned int i;
123
124 if (!numeric) {
125 for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
126 if (TOS_values[i].TOS == tos) {
127 printf("%s ", TOS_values[i].name);
128 return;
129 }
130 }
131 printf("0x%02x ", tos);
132 }
133
134 /* Prints out the targinfo. */
135 static void
print(const struct ipt_ip * ip,const struct ipt_entry_target * target,int numeric)136 print(const struct ipt_ip *ip,
137 const struct ipt_entry_target *target,
138 int numeric)
139 {
140 const struct ipt_tos_target_info *tosinfo =
141 (const struct ipt_tos_target_info *)target->data;
142 printf("TOS set ");
143 print_tos(tosinfo->tos, numeric);
144 }
145
146 /* Saves the union ipt_targinfo in parsable form to stdout. */
147 static void
save(const struct ipt_ip * ip,const struct ipt_entry_target * target)148 save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
149 {
150 const struct ipt_tos_target_info *tosinfo =
151 (const struct ipt_tos_target_info *)target->data;
152
153 printf("--set-tos 0x%02x ", tosinfo->tos);
154 }
155
156 static struct iptables_target tos = {
157 .next = NULL,
158 .name = "TOS",
159 .version = IPTABLES_VERSION,
160 .size = IPT_ALIGN(sizeof(struct ipt_tos_target_info)),
161 .userspacesize = IPT_ALIGN(sizeof(struct ipt_tos_target_info)),
162 .help = &help,
163 .init = &init,
164 .parse = &parse,
165 .final_check = &final_check,
166 .print = &print,
167 .save = &save,
168 .extra_opts = opts
169 };
170
ipt_TOS_init(void)171 void ipt_TOS_init(void)
172 {
173 register_target(&tos);
174 }
175