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discoverInterfaces() correctly ignore non-IPv4 addresses

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Must check sa_family early, before attempting to copy
in case sockaddr needs more storage than sockaddr_in.
This commit is contained in:
Michael Davidsaver
2020-11-20 12:23:18 -08:00
parent 684da91675
commit fc4e3c5d44
1 changed files with 27 additions and 38 deletions
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65
src/utils/inetAddressUtil.cpp
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@@ -200,8 +200,6 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
struct ifconf ifconf; struct ifconf ifconf;
struct ifreq *pIfreqList; struct ifreq *pIfreqList;
struct ifreq *pIfreqListEnd; struct ifreq *pIfreqListEnd;
struct ifreq *pifreq;
struct ifreq *pnextifreq;
int match; int match;
/* /*
@@ -210,13 +208,13 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
* nelem is set to the maximum interfaces * nelem is set to the maximum interfaces
* on one machine here * on one machine here
*/ */
pIfreqList = (struct ifreq *) calloc ( nelem, sizeof(*pifreq) ); pIfreqList = (struct ifreq *) calloc ( nelem, sizeof(*pIfreqList) );
if (!pIfreqList) { if (!pIfreqList) {
errlogPrintf ("discoverInterfaces(): no memory to complete request\n"); errlogPrintf ("discoverInterfaces(): no memory to complete request\n");
return -1; return -1;
} }
ifconf.ifc_len = nelem * sizeof(*pifreq); ifconf.ifc_len = nelem * sizeof(*pIfreqList);
ifconf.ifc_req = pIfreqList; ifconf.ifc_req = pIfreqList;
status = socket_ioctl (socket, SIOCGIFCONF, &ifconf); status = socket_ioctl (socket, SIOCGIFCONF, &ifconf);
if (status < 0 || ifconf.ifc_len == 0) { if (status < 0 || ifconf.ifc_len == 0) {
@@ -226,30 +224,21 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
} }
pIfreqListEnd = (struct ifreq *) (ifconf.ifc_len + (char *) pIfreqList); pIfreqListEnd = (struct ifreq *) (ifconf.ifc_len + (char *) pIfreqList);
pIfreqListEnd--;
for ( pifreq = pIfreqList; pifreq <= pIfreqListEnd; pifreq = pnextifreq ) { for (struct ifreq *pifreq = pIfreqList; pifreq < pIfreqListEnd; pifreq = ifreqNext (pifreq) ) {
uint32_t current_ifreqsize; union {
ifreq req;
// struct ifreq is a tuple of (ifname, union data)
// To accommodate targets with sockaddr::sa_len, make sure
// we have enough storage.
char alloc[sizeof(pIfreqList->ifr_name) + sizeof(sockaddr_in)];
}scratch;
/* if(pifreq->ifr_addr.sa_family != AF_INET)
* find the next ifreq
*/
pnextifreq = ifreqNext (pifreq);
/* determine ifreq size */
current_ifreqsize = ifreqSize ( pifreq );
/* copy current ifreq to aligned bufferspace (to start of pIfreqList buffer) */
/* be careful as we re-use part of this space several times below.
* Any member other than ifr_name is invalidated by an ioctl() call
*/
memmove(pIfreqList, pifreq, current_ifreqsize);
/*
* If its not an internet interface then dont use it
*/
if ( pIfreqList->ifr_addr.sa_family != AF_INET ) {
continue; continue;
}
// copy to ensure aligned access
memcpy(&scratch.req, pifreq, ifreqSize ( pifreq ));
/* /*
* if it isnt a wildcarded interface then look for * if it isnt a wildcarded interface then look for
@@ -261,7 +250,7 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
continue; continue;
} }
if ( pMatchAddr->ia.sin_addr.s_addr != htonl (INADDR_ANY) ) { if ( pMatchAddr->ia.sin_addr.s_addr != htonl (INADDR_ANY) ) {
struct sockaddr_in *pInetAddr = (struct sockaddr_in *) &pIfreqList->ifr_addr; struct sockaddr_in *pInetAddr = (struct sockaddr_in *) &scratch.req.ifr_addr;
if ( pInetAddr->sin_addr.s_addr != pMatchAddr->ia.sin_addr.s_addr ) { if ( pInetAddr->sin_addr.s_addr != pMatchAddr->ia.sin_addr.s_addr ) {
continue; continue;
} }
@@ -271,15 +260,15 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
} }
ifaceNode node; ifaceNode node;
node.addr.sa = pIfreqList->ifr_addr; node.addr.sa = scratch.req.ifr_addr;
status = socket_ioctl ( socket, SIOCGIFFLAGS, pIfreqList ); status = socket_ioctl ( socket, SIOCGIFFLAGS, &scratch.req );
if ( status ) { if ( status ) {
errlogPrintf ("discoverInterfaces(): net intf flags fetch for \"%s\" failed\n", pIfreqList->ifr_name); errlogPrintf ("discoverInterfaces(): net intf flags fetch for \"%s\" failed\n", scratch.req.ifr_name);
continue; continue;
} }
unsigned short ifflags = pIfreqList->ifr_flags; unsigned short ifflags = scratch.req.ifr_flags;
node.loopback = ifflags & IFF_LOOPBACK; node.loopback = ifflags & IFF_LOOPBACK;
/* /*
@@ -309,19 +298,19 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
* interface. * interface.
*/ */
if ( ifflags & IFF_BROADCAST ) { if ( ifflags & IFF_BROADCAST ) {
status = socket_ioctl (socket, SIOCGIFBRDADDR, pIfreqList); status = socket_ioctl (socket, SIOCGIFBRDADDR, &scratch.req);
if ( status ) { if ( status ) {
errlogPrintf ("discoverInterfaces(): net intf \"%s\": bcast addr fetch fail\n", pIfreqList->ifr_name); errlogPrintf ("discoverInterfaces(): net intf \"%s\": bcast addr fetch fail\n", scratch.req.ifr_name);
continue; continue;
} }
node.bcast.sa = pIfreqList->ifr_broadaddr; node.bcast.sa = scratch.req.ifr_broadaddr;
status = socket_ioctl (socket, SIOCGIFNETMASK, pIfreqList); status = socket_ioctl (socket, SIOCGIFNETMASK, &scratch.req);
if ( status ) { if ( status ) {
errlogPrintf ("discoverInterfaces(): net intf \"%s\": netmask fetch fail\n", pIfreqList->ifr_name); errlogPrintf ("discoverInterfaces(): net intf \"%s\": netmask fetch fail\n", scratch.req.ifr_name);
continue; continue;
} }
node.mask.sa = pIfreqList->ifr_netmask; node.mask.sa = scratch.req.ifr_netmask;
checkNode(node); checkNode(node);
@@ -329,11 +318,11 @@ int discoverInterfaces(IfaceNodeVector &list, SOCKET socket, const osiSockAddr *
} }
#if defined (IFF_POINTOPOINT) #if defined (IFF_POINTOPOINT)
else if ( ifflags & IFF_POINTOPOINT ) { else if ( ifflags & IFF_POINTOPOINT ) {
status = socket_ioctl ( socket, SIOCGIFDSTADDR, pIfreqList); status = socket_ioctl ( socket, SIOCGIFDSTADDR, &scratch.req);
if ( status ) { if ( status ) {
continue; continue;
} }
node.peer.sa = pIfreqList->ifr_dstaddr; node.peer.sa = scratch.req.ifr_dstaddr;
node.validP2P = true; node.validP2P = true;
} }
#endif #endif