1 /* Shared library add-on to iptables to add simple load-balance support. */
8 #include <linux/netfilter_ipv4/ip_tables.h>
9 #include <linux/netfilter_ipv4/ip_nat_rule.h>
11 #define BREAKUP_IP(x) (x)>>24, ((x)>>16) & 0xFF, ((x)>>8) & 0xFF, (x) & 0xFF
13 /* Function which prints out usage message. */
18 "BALANCE v%s options:\n"
19 " --to-destination <ipaddr>-<ipaddr>\n"
20 " Addresses to map destination to.\n",
24 static struct option opts
[] = {
25 { "to-destination", 1, 0, '1' },
29 /* Initialize the target. */
31 init(struct ipt_entry_target
*t
, unsigned int *nfcache
)
33 struct ip_nat_multi_range
*mr
= (struct ip_nat_multi_range
*)t
->data
;
35 /* Actually, it's 0, but it's ignored at the moment. */
40 /* Parses range of IPs */
42 parse_to(char *arg
, struct ip_nat_range
*range
)
47 range
->flags
|= IP_NAT_RANGE_MAP_IPS
;
48 dash
= strchr(arg
, '-');
52 exit_error(PARAMETER_PROBLEM
, "Bad IP range `%s'\n", arg
);
54 ip
= dotted_to_addr(arg
);
56 exit_error(PARAMETER_PROBLEM
, "Bad IP address `%s'\n",
58 range
->min_ip
= ip
->s_addr
;
59 ip
= dotted_to_addr(dash
+1);
61 exit_error(PARAMETER_PROBLEM
, "Bad IP address `%s'\n",
63 range
->max_ip
= ip
->s_addr
;
66 /* Function which parses command options; returns true if it
69 parse(int c
, char **argv
, int invert
, unsigned int *flags
,
70 const struct ipt_entry
*entry
,
71 struct ipt_entry_target
**target
)
73 struct ip_nat_multi_range
*mr
74 = (struct ip_nat_multi_range
*)(*target
)->data
;
78 if (check_inverse(optarg
, &invert
, NULL
, 0))
79 exit_error(PARAMETER_PROBLEM
,
80 "Unexpected `!' after --to-destination");
82 parse_to(optarg
, &mr
->range
[0]);
91 /* Final check; need --to-dest. */
92 static void final_check(unsigned int flags
)
95 exit_error(PARAMETER_PROBLEM
,
96 "BALANCE needs --to-destination");
99 /* Prints out the targinfo. */
101 print(const struct ipt_ip
*ip
,
102 const struct ipt_entry_target
*target
,
105 struct ip_nat_multi_range
*mr
106 = (struct ip_nat_multi_range
*)target
->data
;
107 struct ip_nat_range
*r
= &mr
->range
[0];
110 a
.s_addr
= r
->min_ip
;
112 printf("balance %s", addr_to_dotted(&a
));
113 a
.s_addr
= r
->max_ip
;
114 printf("-%s ", addr_to_dotted(&a
));
117 /* Saves the union ipt_targinfo in parsable form to stdout. */
119 save(const struct ipt_ip
*ip
, const struct ipt_entry_target
*target
)
121 struct ip_nat_multi_range
*mr
122 = (struct ip_nat_multi_range
*)target
->data
;
123 struct ip_nat_range
*r
= &mr
->range
[0];
126 a
.s_addr
= r
->min_ip
;
127 printf("--to-destination %s", addr_to_dotted(&a
));
128 a
.s_addr
= r
->max_ip
;
129 printf("-%s ", addr_to_dotted(&a
));
132 static struct iptables_target balance
= {
135 .version
= IPTABLES_VERSION
,
136 .size
= IPT_ALIGN(sizeof(struct ip_nat_multi_range
)),
137 .userspacesize
= IPT_ALIGN(sizeof(struct ip_nat_multi_range
)),
141 .final_check
= &final_check
,
149 register_target(&balance
);