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#include "include/ipaddr.h"
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include "acconfig.h"
#ifdef DARWIN
#ifndef s6_addr16
#define s6_addr16 __u6_addr.__u6_addr16
#endif
#ifndef s6_addr32
#define s6_addr32 __u6_addr.__u6_addr32
#endif
#endif
static void netmask_ipv4(const struct in_addr *addr,
unsigned int prefix_len,
struct in_addr *out) {
uint32_t mask;
if (prefix_len >= 32) {
// also handle 32 in this branch, because >>32 is not defined by
// the C standards
mask = ~uint32_t(0);
} else {
mask = htonl(~(~uint32_t(0) >> prefix_len));
}
out->s_addr = addr->s_addr & mask;
}
const struct sockaddr *find_ipv4_in_subnet(const struct ifaddrs *addrs,
const struct sockaddr_in *net,
unsigned int prefix_len) {
struct in_addr want, temp;
netmask_ipv4(&net->sin_addr, prefix_len, &want);
for (; addrs != NULL; addrs = addrs->ifa_next) {
if (addrs->ifa_addr == NULL)
continue;
if (addrs->ifa_addr->sa_family != net->sin_family)
continue;
struct in_addr *cur = &((struct sockaddr_in*)addrs->ifa_addr)->sin_addr;
netmask_ipv4(cur, prefix_len, &temp);
if (temp.s_addr == want.s_addr) {
return addrs->ifa_addr;
}
}
return NULL;
}
static void netmask_ipv6(const struct in6_addr *addr,
unsigned int prefix_len,
struct in6_addr *out) {
if (prefix_len > 128)
prefix_len = 128;
memcpy(out->s6_addr, addr->s6_addr, prefix_len/8);
if (prefix_len < 128)
out->s6_addr[prefix_len/8] = addr->s6_addr[prefix_len/8] & ~( 0xFF >> (prefix_len % 8) );
if (prefix_len/8 < 15)
memset(out->s6_addr+prefix_len/8+1, 0, 16-prefix_len/8-1);
}
const struct sockaddr *find_ipv6_in_subnet(const struct ifaddrs *addrs,
const struct sockaddr_in6 *net,
unsigned int prefix_len) {
struct in6_addr want, temp;
netmask_ipv6(&net->sin6_addr, prefix_len, &want);
for (; addrs != NULL; addrs = addrs->ifa_next) {
if (addrs->ifa_addr == NULL)
continue;
if (addrs->ifa_addr->sa_family != net->sin6_family)
continue;
struct in6_addr *cur = &((struct sockaddr_in6*)addrs->ifa_addr)->sin6_addr;
netmask_ipv6(cur, prefix_len, &temp);
if (memcmp(temp.s6_addr32, want.s6_addr32, sizeof(temp)) == 0)
return addrs->ifa_addr;
}
return NULL;
}
const struct sockaddr *find_ip_in_subnet(const struct ifaddrs *addrs,
const struct sockaddr *net,
unsigned int prefix_len) {
switch (net->sa_family) {
case AF_INET:
return find_ipv4_in_subnet(addrs, (struct sockaddr_in*)net, prefix_len);
case AF_INET6:
return find_ipv6_in_subnet(addrs, (struct sockaddr_in6*)net, prefix_len);
}
return NULL;
}
bool parse_network(const char *s, struct sockaddr *network, unsigned int *prefix_len) {
char *slash = strchr((char*)s, '/');
if (!slash) {
// no slash
return false;
}
if (*(slash+1) == '\0') {
// slash is the last character
return false;
}
char *end;
long int num = strtol(slash+1, &end, 10);
if (*end != '\0') {
// junk after the prefix_len
return false;
}
if (num < 0) {
return false;
}
*prefix_len = num;
// copy the part before slash to get nil termination
char *addr = (char*)alloca(slash-s + 1);
strncpy(addr, s, slash-s);
addr[slash-s] = '\0';
// caller expects ports etc to be zero
memset(network, 0, sizeof(*network));
// try parsing as ipv4
int ok;
ok = inet_pton(AF_INET, addr, &((struct sockaddr_in*)network)->sin_addr);
if (ok) {
network->sa_family = AF_INET;
return true;
}
// try parsing as ipv6
ok = inet_pton(AF_INET6, addr, &((struct sockaddr_in6*)network)->sin6_addr);
if (ok) {
network->sa_family = AF_INET6;
return true;
}
return false;
}
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