/**
* Canonize interface name. If attempt is not NULL, pick the interface
* which has that address.
* If attempt is NULL, pick interfaces in the following order of preference
* 1. eth0
* 2. Anything starting with eth0:
* 3. Anything starting with eth
* 4. Anything else
* 5. localhost
* 6. zero address
*/
net_if_t *getNetIf(const char *wanted) {
#ifndef __MINGW32__
struct ifreq *ifrp, *ifend, *chosen;
struct ifconf ifc;
int s;
#else /* __MINGW32__ */
int i;
int etherNo=-1;
int wantedEtherNo=-2; /* Wanted ethernet interface */
MIB_IPADDRTABLE *iptab=NULL;
MIB_IFTABLE *iftab=NULL;
MIB_IPADDRROW *iprow, *chosen=NULL;
MIB_IFROW *chosenIf=NULL;
WORD wVersionRequested; /* Version of Winsock to load */
WSADATA wsaData; /* Winsock implementation details */
ULONG a;
int r;
#endif /* __MINGW32__ */
int lastGoodness=0;
struct in_addr wantedAddress;
int isAddress=0;
int wantedLen=0;
net_if_t *net_if;
if(wanted == NULL) {
wanted = getenv("IFNAME");
}
if(wanted && INET_ATON(wanted, &wantedAddress))
isAddress=1;
else
wantedAddress.s_addr=0;
if(wanted)
wantedLen=strlen(wanted);
net_if = MALLOC(net_if_t);
if(net_if == NULL)
udpc_fatal(1, "Out of memory error");
#ifndef __MINGW32__
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("make socket");
exit(1);
}
ifc.ifc_len = sizeof(struct ifreq) * 10;
while(1) {
size_t len = ifc.ifc_len;
ifc.ifc_buf = (caddr_t) malloc(ifc.ifc_len);
if(ifc.ifc_buf == NULL) {
udpc_fatal(1, "Out of memory error");
}
if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0 ||
ifc.ifc_len < (signed int)sizeof(struct ifreq)) {
perror("udpcast: SIOCGIFCONF: ");
exit(1);
}
if(len == ifc.ifc_len) {
ifc.ifc_len += sizeof(struct ifreq) * 10;
free(ifc.ifc_buf);
} else
break;
}
ifend = (struct ifreq *)((char *)ifc.ifc_buf + ifc.ifc_len);
chosen=NULL;
for (ifrp = (struct ifreq *) ifc.ifc_buf ; ifrp < ifend;
#ifdef IFREQ_SIZE
ifrp = IFREQ_SIZE(*ifrp) + (char *)ifrp
#else
ifrp++
#endif
) {
unsigned long iaddr = getSinAddr(&ifrp->ifr_addr).s_addr;
int goodness;
if(ifrp->ifr_addr.sa_family != PF_INET)
continue;
if(wanted) {
if(isAddress && iaddr == wantedAddress.s_addr) {
goodness=8;
} else if(strcmp(wanted, ifrp->ifr_name) ==0) {
/* perfect match on interface name */
goodness=12;
} else if(wanted != NULL &&
strncmp(wanted, ifrp->ifr_name, wantedLen) ==0) {
/* prefix match on interface name */
goodness=7;
} else {
/* no match, try next */
continue;
}
} else {
if(iaddr == 0) {
/* disregard interfaces whose address is zero */
goodness = 1;
} else if(iaddr == htonl(0x7f000001)) {
/* disregard localhost type devices */
goodness = 2;
} else if(strcmp("eth0", ifrp->ifr_name) == 0 ||
strcmp("en0", ifrp->ifr_name) == 0) {
/* prefer first ethernet interface */
goodness = 6;
} else if(strncmp("eth0:", ifrp->ifr_name, 5) == 0) {
/* second choice: any secondary addresses of first ethernet */
goodness = 5;
} else if(strncmp("eth", ifrp->ifr_name, 3) == 0 ||
strncmp("en", ifrp->ifr_name, 2) == 0) {
/* and, if not available, any other ethernet device */
goodness = 4;
} else {
goodness = 3;
}
}
if(hasLink(s, ifrp->ifr_name))
/* Good or unknown link status privileged over known
* disconnected */
goodness += 3;
/* If all else is the same, prefer interfaces that
* have broadcast */
goodness = goodness * 2;
if(goodness >= lastGoodness) {
/* Privilege broadcast-enabled interfaces */
if(ioctl(s, SIOCGIFBRDADDR, ifrp) < 0)
udpc_fatal(-1, "Error getting broadcast address for %s: %s",
ifrp->ifr_name, strerror(errno));
if(getSinAddr(&ifrp->ifr_ifru.ifru_broadaddr).s_addr)
goodness++;
}
if(goodness > lastGoodness) {
chosen = ifrp;
lastGoodness = goodness;
net_if->addr.s_addr = iaddr;
}
}
if(!chosen) {
fprintf(stderr, "No suitable network interface found\n");
fprintf(stderr, "The following interfaces are available:\n");
for (ifrp = (struct ifreq *) ifc.ifc_buf ; ifrp < ifend;
#ifdef IFREQ_SIZE
ifrp = IFREQ_SIZE(*ifrp) + (char *)ifrp
#else
ifrp++
#endif
) {
char buffer[16];
if(ifrp->ifr_addr.sa_family != PF_INET)
continue;
fprintf(stderr, "\t%s\t%s\n",
ifrp->ifr_name,
udpc_getIpString((struct sockaddr_in *)&ifrp->ifr_addr, buffer));
}
exit(1);
}
net_if->name = strdup(chosen->ifr_name);
#ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
/* Index for multicast subscriptions */
if(ioctl(s, SIOCGIFINDEX, chosen) < 0)
udpc_fatal(-1, "Error getting index for %s: %s", net_if->name,
strerror(errno));
net_if->index = chosen->ifr_ifindex;
#endif
/* Broadcast */
if(ioctl(s, SIOCGIFBRDADDR, chosen) < 0)
udpc_fatal(-1, "Error getting broadcast address for %s: %s",
net_if->name, strerror(errno));
net_if->bcast = getSinAddr(&chosen->ifr_ifru.ifru_broadaddr);
close(s);
free(ifc.ifc_buf);
#else /* __MINGW32__ */
/* WINSOCK initialization */
wVersionRequested = MAKEWORD(2, 0); /* Request Winsock v2.0 */
if (WSAStartup(wVersionRequested, &wsaData) != 0) /* Load Winsock DLL */ {
fprintf(stderr,"WSAStartup() failed");
exit(1);
}
/* End WINSOCK initialization */
a=0;
r=GetIpAddrTable(iptab, &a, TRUE);
iptab=malloc(a);
r=GetIpAddrTable(iptab, &a, TRUE);
a=0;
r=GetIfTable(iftab, &a, TRUE);
iftab=malloc(a);
r=GetIfTable(iftab, &a, TRUE);
if(wanted && !strncmp(wanted, "eth", 3) && wanted[3]) {
char *ptr;
int n = strtoul(wanted+3, &ptr, 10);
if(!*ptr)
wantedEtherNo=n;
}
for(i=0; i<iptab->dwNumEntries; i++) {
int goodness=-1;
unsigned long iaddr;
int isEther=0;
MIB_IFROW *ifrow;
iprow = &iptab->table[i];
iaddr = iprow->dwAddr;
ifrow = getIfRow(iftab, iprow->dwIndex);
if(ifrow && ifrow->dwPhysAddrLen == 6 && iprow->dwBCastAddr) {
isEther=1;
etherNo++;
}
if(wanted) {
if(isAddress && iaddr == wantedAddress.s_addr) {
goodness=8;
} else if(isEther && wantedEtherNo == etherNo) {
goodness=9;
} else if(ifrow->dwPhysAddrLen) {
int j;
const char *ptr=wanted;
for(j=0; *ptr && j<ifrow->dwPhysAddrLen; j++) {
int digit = strtoul(ptr, (char**)&ptr, 16);
if(digit != ifrow->bPhysAddr[j])
break; /* Digit mismatch */
if(*ptr == '-' || *ptr == ':') {
ptr++;
}
}
if(!*ptr && j == ifrow->dwPhysAddrLen) {
goodness=9;
}
}
} else {
if(iaddr == 0) {
/* disregard interfaces whose address is zero */
goodness = 1;
} else if(iaddr == htonl(0x7f000001)) {
/* disregard localhost type devices */
goodness = 2;
} else if(isEther) {
/* prefer ethernet */
goodness = 6;
} else if(ifrow->dwPhysAddrLen) {
/* then prefer interfaces which have a physical address */
goodness = 4;
} else {
goodness = 3;
}
}
goodness = goodness * 2;
/* If all else is the same, prefer interfaces that
* have broadcast */
if(goodness >= lastGoodness) {
/* Privilege broadcast-enabled interfaces */
if(iprow->dwBCastAddr)
goodness++;
}
if(goodness > lastGoodness) {
chosen = iprow;
chosenIf = ifrow;
lastGoodness = goodness;
}
}
if(!chosen) {
fprintf(stderr, "No suitable network interface found%s%s\n",
wanted ? " for " : "", wanted ? wanted : "");
fprintf(stderr, "The following interfaces are available:\n");
for(i=0; i<iptab->dwNumEntries; i++) {
char buffer[16];
struct sockaddr_in addr;
MIB_IFROW *ifrow;
char *name=NULL;
iprow = &iptab->table[i];
addr.sin_addr.s_addr = iprow->dwAddr;
ifrow = getIfRow(iftab, iprow->dwIndex);
name = fmtName(ifrow);
fprintf(stderr, " %15s %s\n",
udpc_getIpString(&addr, buffer),
name ? name : "");
if(name)
free(name);
}
exit(1);
}
net_if->bcast.s_addr = net_if->addr.s_addr = chosen->dwAddr;
if(chosen->dwBCastAddr)
net_if->bcast.s_addr |= ~chosen->dwMask;
if(chosenIf) {
net_if->name = fmtName(chosenIf);
} else {
net_if->name = "*";
}
free(iftab);
free(iptab);
#endif /* __MINGW32__ */
return net_if;
}
static int ial_siocgif(INET_ADDR_LIST *addr_list,
INET_ADDR_LIST *mask_list,
int af)
{
const char *myname = "inet_addr_local[siocgif]";
struct in_addr addr;
struct ifconf ifc;
struct ifreq *ifr;
struct ifreq *ifr_mask;
struct ifreq *the_end;
int sock;
VSTRING *buf;
/*
* Get the network interface list. XXX The socket API appears to have no
* function that returns the number of network interfaces, so we have to
* guess how much space is needed to store the result.
*
* On BSD-derived systems, ioctl SIOCGIFCONF returns as much information as
* possible, leaving it up to the application to repeat the request with
* a larger buffer if the result caused a tight fit.
*
* Other systems, such as Solaris 2.5, generate an EINVAL error when the
* buffer is too small for the entire result. Workaround: ignore EINVAL
* errors and repeat the request with a larger buffer. The downside is
* that the program can run out of memory due to a non-memory problem,
* making it more difficult than necessary to diagnose the real problem.
*/
sock = ial_socket(af);
if (sock < 0)
return (0);
buf = vstring_alloc(1024);
for (;;) {
ifc.ifc_len = vstring_avail(buf);
ifc.ifc_buf = vstring_str(buf);
if (ioctl(sock, SIOCGIFCONF, (char *) &ifc) < 0) {
if (errno != EINVAL)
msg_fatal("%s: ioctl SIOCGIFCONF: %m", myname);
} else if (ifc.ifc_len < vstring_avail(buf) / 2)
break;
VSTRING_SPACE(buf, vstring_avail(buf) * 2);
}
the_end = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
for (ifr = ifc.ifc_req; ifr < the_end;) {
if (ifr->ifr_addr.sa_family != af) {
ifr = NEXT_INTERFACE(ifr);
continue;
}
if (af == AF_INET) {
addr = ((struct sockaddr_in *) & ifr->ifr_addr)->sin_addr;
if (addr.s_addr != INADDR_ANY) {
inet_addr_list_append(addr_list, &ifr->ifr_addr);
if (mask_list) {
ifr_mask = (struct ifreq *) mymalloc(IFREQ_SIZE(ifr));
memcpy((void *) ifr_mask, (void *) ifr, IFREQ_SIZE(ifr));
if (ioctl(sock, SIOCGIFNETMASK, ifr_mask) < 0)
msg_fatal("%s: ioctl SIOCGIFNETMASK: %m", myname);
/*
* Note that this SIOCGIFNETMASK has truly screwed up the
* contents of sa_len/sa_family. We must fix this
* manually to have correct addresses. --dcs
*/
ifr_mask->ifr_addr.sa_family = af;
#ifdef HAS_SA_LEN
ifr_mask->ifr_addr.sa_len = sizeof(struct sockaddr_in);
#endif
inet_addr_list_append(mask_list, &ifr_mask->ifr_addr);
myfree((void *) ifr_mask);
}
}
}
#ifdef HAS_IPV6
else if (af == AF_INET6) {
struct sockaddr *sa;
sa = SOCK_ADDR_PTR(&ifr->ifr_addr);
if (!(IN6_IS_ADDR_UNSPECIFIED(&SOCK_ADDR_IN6_ADDR(sa)))) {
inet_addr_list_append(addr_list, sa);
if (mask_list) {
/* XXX Assume /128 for everything */
struct sockaddr_in6 mask6;
mask6 = *SOCK_ADDR_IN6_PTR(sa);
memset((void *) &mask6.sin6_addr, ~0,
sizeof(mask6.sin6_addr));
inet_addr_list_append(mask_list, SOCK_ADDR_PTR(&mask6));
}
}
}
#endif
ifr = NEXT_INTERFACE(ifr);
}
vstring_free(buf);
(void) close(sock);
return (0);
}
