The first implementation of the IP translation functions in
cb75e019e74fc11f9547dadd51abbf3c9df2c5e7 ("batctl: Allow to use IPv4 addresses
for ping/traceroute") had is focus on implementing it only for IPv4. This is a
limitation when other layer 3 protocols are used.For example, a port to IPv6 would either have to copy the functionality or do a major refactoring when implementing the it resolv functionality. This is not necessary when the functions already expect different layer 3 protocols in the first place and make it easy to find the right place to modify them. Signed-off-by: Sven Eckelmann <[email protected]> --- functions.c | 86 ++++++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 63 insertions(+), 23 deletions(-) diff --git a/functions.c b/functions.c index 1a33d6d..e4aeb72 100644 --- a/functions.c +++ b/functions.c @@ -416,49 +416,68 @@ out: return mac_result; } -static uint32_t resolve_ipv4(const char *asc) +static int resolve_l3addr(int ai_family, const char *asc, void *l3addr) { int ret; struct addrinfo hints; struct addrinfo *res; struct sockaddr_in *inet4; - uint32_t addr = 0; memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_INET; + hints.ai_family = ai_family; ret = getaddrinfo(asc, NULL, &hints, &res); if (ret) - return 0; + return -EADDRNOTAVAIL; if (res) { - inet4 = (struct sockaddr_in *)res->ai_addr; - addr = inet4->sin_addr.s_addr; + switch (ai_family) { + case AF_INET: + inet4 = (struct sockaddr_in *)res->ai_addr; + memcpy(l3addr, &inet4->sin_addr.s_addr, + sizeof(inet4->sin_addr.s_addr)); + break; + default: + ret = -EINVAL; + } } freeaddrinfo(res); - return addr; + return ret; } -static void request_arp(uint32_t ipv4_addr) +static void request_mac_resolve(int ai_family, const void *l3addr) { + const struct sockaddr *sockaddr; struct sockaddr_in inet4; + size_t sockaddr_len; int sock; char t = 0; - memset(&inet4, 0, sizeof(inet4)); - sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + sock = socket(ai_family, SOCK_DGRAM, IPPROTO_UDP); if (sock < 0) return; - inet4.sin_family = AF_INET; - inet4.sin_port = htons(9); - inet4.sin_addr.s_addr = ipv4_addr; - sendto(sock, &t, sizeof(t), 0, (const struct sockaddr *)&inet4, - sizeof(inet4)); + switch (ai_family) { + case AF_INET: + memset(&inet4, 0, sizeof(inet4)); + inet4.sin_family = ai_family; + inet4.sin_port = htons(9); + memcpy(&inet4.sin_addr.s_addr, l3addr, + sizeof(inet4.sin_addr.s_addr)); + sockaddr = (const struct sockaddr *)&inet4; + sockaddr_len = sizeof(inet4); + break; + default: + close(sock); + return; + } + + sendto(sock, &t, sizeof(t), 0, sockaddr, sockaddr_len); close(sock); } -static struct ether_addr *resolve_mac_from_arp(uint32_t ipv4_addr) +static struct ether_addr *resolve_mac_from_cache(int ai_family, + const void *l3addr) { struct ether_addr mac_empty; struct ether_addr *mac_result = NULL, *mac_tmp = NULL; @@ -471,7 +490,12 @@ static struct ether_addr *resolve_mac_from_arp(uint32_t ipv4_addr) size_t column; char *token, *input, *saveptr; int line_invalid; + uint32_t ipv4_addr; + if (ai_family != AF_INET) + return NULL; + + memcpy(&ipv4_addr, l3addr, sizeof(ipv4_addr)); memset(&mac_empty, 0, sizeof(mac_empty)); f = fopen("/proc/net/arp", "r"); @@ -527,20 +551,30 @@ static struct ether_addr *resolve_mac_from_arp(uint32_t ipv4_addr) return mac_result; } -static struct ether_addr *resolve_mac_from_ipv4(const char *asc) +static struct ether_addr *resolve_mac_from_addr(int ai_family, const char *asc) { - uint32_t ipv4_addr; + uint8_t ipv4_addr[4]; + void *l3addr; + int ret; int retries = 5; struct ether_addr *mac_result = NULL; - ipv4_addr = resolve_ipv4(asc); - if (!ipv4_addr) + switch (ai_family) { + case AF_INET: + l3addr = ipv4_addr; + break; + default: + return NULL; + } + + ret = resolve_l3addr(ai_family, asc, l3addr); + if (ret < 0) return NULL; while (retries-- && !mac_result) { - mac_result = resolve_mac_from_arp(ipv4_addr); + mac_result = resolve_mac_from_cache(ai_family, l3addr); if (!mac_result) { - request_arp(ipv4_addr); + request_mac_resolve(ai_family, l3addr); usleep(200000); } } @@ -551,12 +585,18 @@ static struct ether_addr *resolve_mac_from_ipv4(const char *asc) struct ether_addr *resolve_mac(const char *asc) { struct ether_addr *mac_result = NULL; + static const int ai_families[] = {AF_INET}; + size_t i; mac_result = ether_aton(asc); if (mac_result) goto out; - mac_result = resolve_mac_from_ipv4(asc); + for (i = 0; i < sizeof(ai_families) / sizeof(*ai_families); i++) { + mac_result = resolve_mac_from_addr(ai_families[i], asc); + if (mac_result) + goto out; + } out: return mac_result; -- 1.8.4.rc3
