diff options
Diffstat (limited to '')
| -rw-r--r-- | src/common/ipaddr.cc | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/src/common/ipaddr.cc b/src/common/ipaddr.cc new file mode 100644 index 000000000..8c5da54b9 --- /dev/null +++ b/src/common/ipaddr.cc @@ -0,0 +1,180 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab + +#include <arpa/inet.h> +#include <ifaddrs.h> +#include <stdlib.h> +#include <string.h> +#if defined(__FreeBSD__) +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#endif + +#include "include/ipaddr.h" +#include "msg/msg_types.h" +#include "common/pick_address.h" + +using std::string; + +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; +} + +bool matches_ipv4_in_subnet(const struct ifaddrs& addrs, + const struct sockaddr_in* net, + unsigned int prefix_len) +{ + if (addrs.ifa_addr == nullptr) + return false; + + if (addrs.ifa_addr->sa_family != net->sin_family) + return false; + struct in_addr want; + netmask_ipv4(&net->sin_addr, prefix_len, &want); + struct in_addr *cur = &((struct sockaddr_in*)addrs.ifa_addr)->sin_addr; + struct in_addr temp; + netmask_ipv4(cur, prefix_len, &temp); + return temp.s_addr == want.s_addr; +} + +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); +} + +bool matches_ipv6_in_subnet(const struct ifaddrs& addrs, + const struct sockaddr_in6* net, + unsigned int prefix_len) +{ + if (addrs.ifa_addr == nullptr) + return false; + + if (addrs.ifa_addr->sa_family != net->sin6_family) + return false; + struct in6_addr want; + netmask_ipv6(&net->sin6_addr, prefix_len, &want); + struct in6_addr temp; + struct in6_addr *cur = &((struct sockaddr_in6*)addrs.ifa_addr)->sin6_addr; + if (IN6_IS_ADDR_LINKLOCAL(cur)) + return false; + netmask_ipv6(cur, prefix_len, &temp); + return IN6_ARE_ADDR_EQUAL(&temp, &want); +} + +bool parse_network(const char *s, struct sockaddr_storage *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->ss_family = AF_INET; + return true; + } + + // try parsing as ipv6 + ok = inet_pton(AF_INET6, addr, &((struct sockaddr_in6*)network)->sin6_addr); + if (ok) { + network->ss_family = AF_INET6; + return true; + } + + return false; +} + +bool parse_network(const char *s, + entity_addr_t *network, + unsigned int *prefix_len) +{ + sockaddr_storage ss; + bool ret = parse_network(s, &ss, prefix_len); + if (ret) { + network->set_type(entity_addr_t::TYPE_LEGACY); + network->set_sockaddr((sockaddr *)&ss); + } + return ret; +} + +bool network_contains( + const struct entity_addr_t& network, + unsigned int prefix_len, + const struct entity_addr_t& addr) +{ + if (addr.get_family() != network.get_family()) { + return false; + } + switch (network.get_family()) { + case AF_INET: + { + struct in_addr a, b; + netmask_ipv4( + &((const sockaddr_in*)network.get_sockaddr())->sin_addr, prefix_len, &a); + netmask_ipv4( + &((const sockaddr_in*)addr.get_sockaddr())->sin_addr, prefix_len, &b); + if (memcmp(&a, &b, sizeof(a)) == 0) { + return true; + } + } + break; + case AF_INET6: + { + struct in6_addr a, b; + netmask_ipv6( + &((const sockaddr_in6*)network.get_sockaddr())->sin6_addr, prefix_len, &a); + netmask_ipv6( + &((const sockaddr_in6*)addr.get_sockaddr())->sin6_addr, prefix_len, &b); + if (memcmp(&a, &b, sizeof(a)) == 0) { + return true; + } + } + break; + } + return false; +} |