/*
* For all bits set in "mask", compare the corresponding bits in
* "dst" and "src", and see if they match. Returns 0 if the addresses
* match.
*/
static int
bitmaskcmp(struct sockaddr *dst, struct sockaddr *src, struct sockaddr *mask)
{
int i;
u_int8_t *p1, *p2, *netmask;
int bytelen;
if (dst->sa_family != src->sa_family ||
dst->sa_family != mask->sa_family)
return (1);
switch (dst->sa_family) {
case AF_INET:
p1 = (uint8_t*) &SA2SINADDR(dst);
p2 = (uint8_t*) &SA2SINADDR(src);
netmask = (uint8_t*) &SA2SINADDR(mask);
bytelen = sizeof(struct in_addr);
break;
#ifdef INET6
case AF_INET6:
p1 = (uint8_t*) &SA2SIN6ADDR(dst);
p2 = (uint8_t*) &SA2SIN6ADDR(src);
netmask = (uint8_t*) &SA2SIN6ADDR(mask);
bytelen = sizeof(struct in6_addr);
break;
#endif
default:
return (1);
}
for (i = 0; i < bytelen; i++)
if ((p1[i] & netmask[i]) != (p2[i] & netmask[i]))
return (1);
return (0);
}
/*
* Match the sa against the list of addresses we've bound to. If
* we've not specifically bound to anything, we match everything.
* Otherwise, if the IPv4 or IPv6 address matches one of the addresses
* in bound_sa, we return true. If not, we return false.
*/
int
listen_addr(const struct sockaddr *sa)
{
int i;
/*
* If nhosts == 0, then there were no -h options on the
* command line, so all addresses are addresses we're
* listening to.
*/
if (nhosts == 0)
return 1;
for (i = 0; i < nhosts; i++) {
if (bound_sa[i] == NULL ||
sa->sa_family != bound_sa[i]->sa_family)
continue;
switch (sa->sa_family) {
case AF_INET:
if (memcmp(&SA2SINADDR(sa), &SA2SINADDR(bound_sa[i]),
sizeof(struct in_addr)) == 0)
return (1);
break;
#ifdef INET6
case AF_INET6:
if (memcmp(&SA2SIN6ADDR(sa), &SA2SIN6ADDR(bound_sa[i]),
sizeof(struct in6_addr)) == 0)
return (1);
break;
#endif
default:
break;
}
}
return (0);
}
/*
* Find a server address that can be used by `caller' to contact
* the local service specified by `serv_uaddr'. If `clnt_uaddr' is
* non-NULL, it is used instead of `caller' as a hint suggesting
* the best address (e.g. the `r_addr' field of an rpc, which
* contains the rpcbind server address that the caller used).
*
* Returns the best server address as a malloc'd "universal address"
* string which should be freed by the caller. On error, returns NULL.
*/
char *
addrmerge(arpc_addr_t *caller, const char *serv_uaddr, const char *clnt_uaddr,
const char *netid)
{
struct ifaddrs *ifap, *ifp = NULL, *bestif;
arpc_addr_t *serv_nbp = NULL, *hint_nbp = NULL, tbuf;
struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa;
struct sockaddr_storage ss;
socklen_t len;
const char *hint_uaddr = NULL;
char *caller_uaddr = NULL;
char *ret = NULL;
int err;
#ifdef ND_DEBUG
if (debugging)
fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr,
clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid);
#endif
caller_sa = (struct sockaddr *)caller->buf;
err = ar_taddr2uaddr(rpcbind_ioctx, netid, caller, &caller_uaddr);
if (err != 0) {
goto freeit;
}
/*
* Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its
* address family is different from that of the caller.
*/
hint_sa = NULL;
if (clnt_uaddr != NULL) {
hint_uaddr = clnt_uaddr;
err = ar_uaddr2taddr(rpcbind_ioctx, netid,
clnt_uaddr, &hint_nbp);
if (err != 0) {
goto freeit;
}
hint_sa = (struct sockaddr *)hint_nbp->buf;
}
if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) {
hint_uaddr = caller_uaddr;
hint_sa = (struct sockaddr *)caller->buf;
}
#ifdef ND_DEBUG
if (debugging) {
fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr);
}
#endif
/* Local caller, just return the server address. */
if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 ||
strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') {
ret = strdup(serv_uaddr);
goto freeit;
}
if (getifaddrs(&ifp) < 0) {
goto freeit;
}
/*
* Loop through all interfaces. For each interface, see if the
* network portion of its address is equal to that of the client.
* If so, we have found the interface that we want to use.
*/
bestif = NULL;
for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
ifsa = ifap->ifa_addr;
ifmasksa = ifap->ifa_netmask;
if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family ||
!(ifap->ifa_flags & IFF_UP)) {
continue;
}
switch (hint_sa->sa_family) {
case AF_INET:
/*
* If the hint address matches this interface
* address/netmask, then we're done.
*/
if (!bitmaskcmp(&SA2SINADDR(ifsa),
&SA2SINADDR(hint_sa), &SA2SINADDR(ifmasksa),
sizeof(struct in_addr))) {
bestif = ifap;
goto found;
}
break;
case AF_INET6:
/*
* For v6 link local addresses, if the caller is on
* a link-local address then use the scope id to see
* which one.
*/
in6_fillscopeid(SA2SIN6(ifsa));
if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) &&
IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) &&
IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) {
if (SA2SIN6(ifsa)->sin6_scope_id ==
SA2SIN6(caller_sa)->sin6_scope_id) {
bestif = ifap;
goto found;
}
} else if (!bitmaskcmp(&SA2SIN6ADDR(ifsa),
&SA2SIN6ADDR(hint_sa), &SA2SIN6ADDR(ifmasksa),
sizeof(struct in6_addr))) {
bestif = ifap;
goto found;
}
break;
default:
continue;
}
/*
* Remember the first possibly useful interface, preferring
* "normal" to point-to-point and loopback ones.
*/
if (bestif == NULL ||
(!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) &&
(bestif->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)))) {
bestif = ifap;
}
}
if (bestif == NULL) {
goto freeit;
}
found:
/*
* Construct the new address using the the address from
* `bestif', and the port number from `serv_uaddr'.
*/
err = ar_uaddr2taddr(rpcbind_ioctx, netid, serv_uaddr, &serv_nbp);
if (err != 0) {
goto freeit;
}
serv_sa = (struct sockaddr *)serv_nbp->buf;
switch (ss.ss_family) {
case AF_INET:
len = sizeof(struct sockaddr_in);
memcpy(&ss, bestif->ifa_addr, len);
SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port;
break;
case AF_INET6:
len = sizeof(struct sockaddr_in6);
memcpy(&ss, bestif->ifa_addr, len);
SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port;
break;
default:
memset(&ss, 0, sizeof(ss));
len = 0;
break;
}
tbuf.len = len;
tbuf.maxlen = sizeof(ss);
tbuf.buf = (char *)&ss;
err = ar_taddr2uaddr(rpcbind_ioctx, netid, &tbuf, &ret);
if (err != 0) {
ret = NULL;
}
freeit:
if (caller_uaddr != NULL) {
free(caller_uaddr);
}
if (hint_nbp != NULL) {
if (hint_nbp->buf) {
free(hint_nbp->buf);
}
free(hint_nbp);
}
if (serv_nbp != NULL) {
if (serv_nbp->buf) {
free(serv_nbp->buf);
}
free(serv_nbp);
}
if (ifp != NULL) {
freeifaddrs(ifp);
}
#ifdef ND_DEBUG
if (debugging) {
fprintf(stderr, "addrmerge: returning %s\n", ret);
}
#endif
return ret;
}
