1 #include <stdio.h>
2 #include <xtables.h>
3 #include <linux/netfilter_ipv4/ipt_ah.h>
4 
5 enum {
6 	O_AHSPI = 0,
7 };
8 
ah_help(void)9 static void ah_help(void)
10 {
11 	printf(
12 "ah match options:\n"
13 "[!] --ahspi spi[:spi]\n"
14 "				match spi (range)\n");
15 }
16 
17 static const struct xt_option_entry ah_opts[] = {
18 	{.name = "ahspi", .id = O_AHSPI, .type = XTTYPE_UINT32RC,
19 	 .flags = XTOPT_INVERT | XTOPT_PUT,
20 	 XTOPT_POINTER(struct ipt_ah, spis)},
21 	XTOPT_TABLEEND,
22 };
23 
ah_init(struct xt_entry_match * m)24 static void ah_init(struct xt_entry_match *m)
25 {
26 	struct ipt_ah *ahinfo = (void *)m->data;
27 
28 	ahinfo->spis[1] = ~0U;
29 }
30 
ah_parse(struct xt_option_call * cb)31 static void ah_parse(struct xt_option_call *cb)
32 {
33 	struct ipt_ah *ahinfo = cb->data;
34 
35 	xtables_option_parse(cb);
36 	if (cb->nvals == 1)
37 		ahinfo->spis[1] = ahinfo->spis[0];
38 	if (cb->invert)
39 		ahinfo->invflags |= IPT_AH_INV_SPI;
40 }
41 
42 static void
print_spis(const char * name,uint32_t min,uint32_t max,int invert)43 print_spis(const char *name, uint32_t min, uint32_t max,
44 	    int invert)
45 {
46 	const char *inv = invert ? "!" : "";
47 
48 	if (min != 0 || max != 0xFFFFFFFF || invert) {
49 		printf("%s", name);
50 		if (min == max) {
51 			printf(":%s", inv);
52 			printf("%u", min);
53 		} else {
54 			printf("s:%s", inv);
55 			printf("%u",min);
56 			printf(":");
57 			printf("%u",max);
58 		}
59 	}
60 }
61 
ah_print(const void * ip,const struct xt_entry_match * match,int numeric)62 static void ah_print(const void *ip, const struct xt_entry_match *match,
63                      int numeric)
64 {
65 	const struct ipt_ah *ah = (struct ipt_ah *)match->data;
66 
67 	printf(" ah ");
68 	print_spis("spi", ah->spis[0], ah->spis[1],
69 		    ah->invflags & IPT_AH_INV_SPI);
70 	if (ah->invflags & ~IPT_AH_INV_MASK)
71 		printf(" Unknown invflags: 0x%X",
72 		       ah->invflags & ~IPT_AH_INV_MASK);
73 }
74 
ah_save(const void * ip,const struct xt_entry_match * match)75 static void ah_save(const void *ip, const struct xt_entry_match *match)
76 {
77 	const struct ipt_ah *ahinfo = (struct ipt_ah *)match->data;
78 
79 	if (!(ahinfo->spis[0] == 0
80 	    && ahinfo->spis[1] == 0xFFFFFFFF)) {
81 		printf("%s --ahspi ",
82 			(ahinfo->invflags & IPT_AH_INV_SPI) ? " !" : "");
83 		if (ahinfo->spis[0]
84 		    != ahinfo->spis[1])
85 			printf("%u:%u",
86 			       ahinfo->spis[0],
87 			       ahinfo->spis[1]);
88 		else
89 			printf("%u",
90 			       ahinfo->spis[0]);
91 	}
92 
93 }
94 
ah_xlate(struct xt_xlate * xl,const struct xt_xlate_mt_params * params)95 static int ah_xlate(struct xt_xlate *xl,
96 		    const struct xt_xlate_mt_params *params)
97 {
98 	const struct ipt_ah *ahinfo = (struct ipt_ah *)params->match->data;
99 
100 	if (!(ahinfo->spis[0] == 0 && ahinfo->spis[1] == 0xFFFFFFFF)) {
101 		xt_xlate_add(xl, "ah spi%s ",
102 			   (ahinfo->invflags & IPT_AH_INV_SPI) ? " !=" : "");
103 		if (ahinfo->spis[0] != ahinfo->spis[1])
104 			xt_xlate_add(xl, "%u-%u", ahinfo->spis[0],
105 				   ahinfo->spis[1]);
106 		else
107 			xt_xlate_add(xl, "%u", ahinfo->spis[0]);
108 	}
109 
110 	return 1;
111 }
112 
113 static struct xtables_match ah_mt_reg = {
114 	.name		= "ah",
115 	.version	= XTABLES_VERSION,
116 	.family		= NFPROTO_IPV4,
117 	.size		= XT_ALIGN(sizeof(struct ipt_ah)),
118 	.userspacesize	= XT_ALIGN(sizeof(struct ipt_ah)),
119 	.help		= ah_help,
120 	.init		= ah_init,
121 	.print		= ah_print,
122 	.save		= ah_save,
123 	.x6_parse	= ah_parse,
124 	.x6_options	= ah_opts,
125 	.xlate		= ah_xlate,
126 };
127 
128 void
_init(void)129 _init(void)
130 {
131 	xtables_register_match(&ah_mt_reg);
132 }
133