#include <unistd.h>
#include <sys/ioctl.h>
-static struct ifaddrs* list_add(struct ifaddrs** list, struct ifaddrs** head, char* ifname)
+typedef union {
+ struct sockaddr_in6 v6;
+ struct sockaddr_in v4;
+} soa;
+
+typedef struct ifaddrs_storage {
+ struct ifaddrs ifa;
+ soa addr;
+ soa netmask;
+ soa dst;
+ char name[IFNAMSIZ+1];
+} stor;
+#define next ifa.ifa_next
+
+static stor* list_add(stor** list, stor** head, char* ifname)
{
- struct ifaddrs* curr = calloc(1, sizeof(struct ifaddrs));
+ stor* curr = calloc(1, sizeof(stor));
if(curr) {
- curr->ifa_name = strdup(ifname);
- if(!curr->ifa_name) {
- free(curr);
- curr = 0;
- goto out;
- }
- if(*head) (*head)->ifa_next = curr;
+ strcpy(curr->name, ifname);
+ curr->ifa.ifa_name = curr->name;
+ if(*head) (*head)->next = (struct ifaddrs*) curr;
*head = curr;
if(!*list) *list = curr;
}
- out:
return curr;
}
void freeifaddrs(struct ifaddrs *ifp)
{
- struct ifaddrs *head = ifp;
+ stor *head = (stor *) ifp;
while(head) {
- free(head->ifa_name);
- free(head->ifa_addr);
- free(head->ifa_netmask);
- free(head->ifa_ifu.ifu_dstaddr);
- free(head->ifa_data);
void *p = head;
- head = head->ifa_next;
+ head = (stor *) head->next;
free(p);
}
}
-static struct sockaddr *sockaddr_in_dup(struct sockaddr_in *src)
-{
- struct sockaddr_in *nu = malloc(sizeof(struct sockaddr_in));
- if(nu) *nu = *src;
- return (struct sockaddr*) nu;
-}
-
-static struct sockaddr *sockaddr_in6_dup(struct sockaddr_in6 *src)
-{
- struct sockaddr_in6 *nu = malloc(sizeof(struct sockaddr_in6));
- if(nu) *nu = *src;
- return (struct sockaddr*) nu;
-}
-
static void ipv6netmask(unsigned prefix_length, struct sockaddr_in6 *sa)
{
- // FIXME: left for bit-wizard rich
- memset(&sa->sin6_addr, -1, sizeof(sa->sin6_addr));
+ unsigned char* hb = sa->sin6_addr.s6_addr;
+ unsigned onebytes = prefix_length / 8;
+ unsigned bits = prefix_length % 8;
+ unsigned nullbytes = 16 - onebytes;
+ memset(hb, -1, onebytes);
+ memset(hb+onebytes, 0, nullbytes);
+ if(bits) {
+ unsigned char x = -1;
+ x <<= 8 - bits;
+ hb[onebytes] = x;
+ }
}
-static void dealwithipv6(struct ifaddrs **list, struct ifaddrs** head)
+static void dealwithipv6(stor **list, stor** head)
{
FILE* f = fopen("/proc/net/if_inet6", "r");
/* 00000000000000000000000000000001 01 80 10 80 lo
struct sockaddr_in6 sa = {0};
if(1 == inet_pton(AF_INET6, v6conv, &sa.sin6_addr)) {
sa.sin6_family = AF_INET6;
- struct ifaddrs* curr = list_add(list, head, name);
+ stor* curr = list_add(list, head, name);
if(!curr) goto out;
- curr->ifa_addr = sockaddr_in6_dup(&sa);
+ curr->addr.v6 = sa;
+ curr->ifa.ifa_addr = (struct sockaddr*) &curr->addr;
ipv6netmask(c, &sa);
- curr->ifa_netmask = sockaddr_in6_dup(&sa);
+ curr->netmask.v6 = sa;
+ curr->ifa.ifa_netmask = (struct sockaddr*) &curr->netmask;
/* find ipv4 struct with the same interface name to copy flags */
- struct ifaddrs* scan = *list;
- for(;scan && strcmp(name, scan->ifa_name);scan=scan->ifa_next);
- if(scan) curr->ifa_flags=scan->ifa_flags;
- else curr->ifa_flags = 0;
+ stor* scan = *list;
+ for(;scan && strcmp(name, scan->name);scan=(stor*)scan->next);
+ if(scan) curr->ifa.ifa_flags = scan->ifa.ifa_flags;
+ else curr->ifa.ifa_flags = 0;
} else errno = 0;
}
}
int getifaddrs(struct ifaddrs **ifap)
{
- FILE* f = fopen("/proc/net/dev", "r");
- /* the alternative to parsing /proc.. seems to be iterating
- through the interfaces using an index number in ifreq.ifr_ifindex
- until we get some error code back. the kernel will fill ifr_name field
- for valid ifindices (SIOCGIFINDEX) */
- if(!f) return -1;
- struct ifaddrs *list = 0, *head = 0;
-
- char* line; char linebuf[512];
- while((line = fgets(linebuf, sizeof linebuf, f))) {
- while(isspace(*line) && *line) line++;
- char* start = line;
- while(*line && isalnum(*line)) line++;
- if(line > start && *line == ':') {
- // found interface
- *line = 0;
- struct ifaddrs* curr = list_add(&list, &head, start);
- if(!curr) {
- fclose(f);
- goto err2;
- }
+ stor *list = 0, *head = 0;
+ struct if_nameindex* ii = if_nameindex();
+ if(!ii) return -1;
+ size_t i;
+ for(i = 0; ii[i].if_index || ii[i].if_name; i++) {
+ stor* curr = list_add(&list, &head, ii[i].if_name);
+ if(!curr) {
+ if_freenameindex(ii);
+ goto err2;
}
}
- fclose(f);
+ if_freenameindex(ii);
- int sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
+ int sock = socket(PF_INET, SOCK_DGRAM|SOCK_CLOEXEC, IPPROTO_IP);
if(sock == -1) goto err2;
struct ifreq reqs[32]; /* arbitrary chosen boundary */
struct ifconf conf = {.ifc_len = sizeof reqs, .ifc_req = reqs};
if(-1 == ioctl(sock, SIOCGIFCONF, &conf)) goto err;
- else {
- size_t reqitems = conf.ifc_len / sizeof(struct ifreq);
- for(head = list; head; head=head->ifa_next) {
- size_t i;
- for(i = 0; i < reqitems; i++) {
- // get SIOCGIFADDR of active interfaces.
- if(!strcmp(reqs[i].ifr_name, head->ifa_name)) {
- head->ifa_addr = sockaddr_in_dup((struct sockaddr_in*) &reqs[i].ifr_addr);
- break;
- }
+ size_t reqitems = conf.ifc_len / sizeof(struct ifreq);
+ for(head = list; head; head = (stor*)head->next) {
+ for(i = 0; i < reqitems; i++) {
+ // get SIOCGIFADDR of active interfaces.
+ if(!strcmp(reqs[i].ifr_name, head->name)) {
+ head->addr.v4 = *(struct sockaddr_in*)&reqs[i].ifr_addr;
+ head->ifa.ifa_addr = (struct sockaddr*) &head->addr;
+ break;
}
- struct ifreq req;
- snprintf(req.ifr_name, sizeof req.ifr_name, "%s", head->ifa_name);
- if(-1 == ioctl(sock, SIOCGIFFLAGS, &req)) goto err;
+ }
+ struct ifreq req;
+ snprintf(req.ifr_name, sizeof req.ifr_name, "%s", head->name);
+ if(-1 == ioctl(sock, SIOCGIFFLAGS, &req)) goto err;
- head->ifa_flags = req.ifr_flags;
- if(head->ifa_addr) {
- /* or'ing flags with IFF_LOWER_UP on active interfaces to mimic glibc */
- head->ifa_flags |= IFF_LOWER_UP;
- if(-1 == ioctl(sock, SIOCGIFNETMASK, &req)) goto err;
- head->ifa_netmask = sockaddr_in_dup((struct sockaddr_in*) &req.ifr_netmask);
-
- if(head->ifa_flags & IFF_POINTOPOINT) {
- if(-1 == ioctl(sock, SIOCGIFDSTADDR, &req)) goto err;
- head->ifa_ifu.ifu_dstaddr = sockaddr_in_dup((struct sockaddr_in*) &req.ifr_dstaddr);
- } else {
- if(-1 == ioctl(sock, SIOCGIFBRDADDR, &req)) goto err;
- head->ifa_ifu.ifu_broadaddr = sockaddr_in_dup((struct sockaddr_in*) &req.ifr_broadaddr);
- }
+ head->ifa.ifa_flags = req.ifr_flags;
+ if(head->ifa.ifa_addr) {
+ /* or'ing flags with IFF_LOWER_UP on active interfaces to mimic glibc */
+ head->ifa.ifa_flags |= IFF_LOWER_UP;
+ if(-1 == ioctl(sock, SIOCGIFNETMASK, &req)) goto err;
+ head->netmask.v4 = *(struct sockaddr_in*)&req.ifr_netmask;
+ head->ifa.ifa_netmask = (struct sockaddr*) &head->netmask;
+
+ if(head->ifa.ifa_flags & IFF_POINTOPOINT) {
+ if(-1 == ioctl(sock, SIOCGIFDSTADDR, &req)) goto err;
+ head->dst.v4 = *(struct sockaddr_in*)&req.ifr_dstaddr;
+ } else {
+ if(-1 == ioctl(sock, SIOCGIFBRDADDR, &req)) goto err;
+ head->dst.v4 = *(struct sockaddr_in*)&req.ifr_broadaddr;
}
+ head->ifa.ifa_ifu.ifu_dstaddr = (struct sockaddr*) &head->dst;
}
}
close(sock);
void* last = 0;
- for(head = list; head; head=head->ifa_next) last=head;
+ for(head = list; head; head=(stor*)head->next) last=head;
head = last;
dealwithipv6(&list, &head);
- *ifap = list;
+ *ifap = (struct ifaddrs*) list;
return 0;
err:
close(sock);
err2:
- freeifaddrs(list);
+ freeifaddrs((struct ifaddrs*) list);
return -1;
}