How to set a specified IPv6 address to ff_bind() without error?

[NOH Myungkyu]

Hello.

I want to assign IPv6 address to ff_bind(), but I see the error as "ff_bind failed, errno:99, Cannot assign requested address".
Please answer to solve this issue.

1. Source (UDP Server)

struct sockaddr_in6 local_addr6;
bzero(&local_addr6, sizeof(local_addr6));
local_addr6.sin6_family = AF_INET6;
local_addr6.sin6_port = htons(8888);

int ret = inet_pton(AF_INET6, "fe80::fd98:f6de:1d5f:6c33", (void *)&local_addr6.sin6_addr);

ret = ff_bind(sockfd6, (struct linux_sockaddr *)&local_addr6, sizeof(local_addr6));
if (ret < 0) {
	printf("ERROR: sockfd6=%d, ff_bind failed, errno:%d, %s \n", sockfd6, errno, strerror(errno));
	exit(1);
}

2. Config file (config.ini)

[port0]
addr=172.16.1.1
netmask=255.255.0.0
broadcast=172.16.255.255
gateway=172.16.0.1

addr6=fe80::fd98:f6de:1d5f:6c33
prefix_len=64
gateway6=fe80::78fb:808e:c4d4:f61c

[NOH Myungkyu]

I found out the setting IPv6 address (config.ini and binding to socket) and IPv6 address of ifa_link struct are different.

freebsd/net/if.c

   1756 static struct ifaddr *
   1757 ifa_ifwithaddr_internal(const struct sockaddr *addr, int getref)
   1758 {
   1759     struct ifnet *ifp;
   1760     struct ifaddr *ifa;
   1761
   1762     IFNET_RLOCK_NOSLEEP();
   1763     TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
   1764         IF_ADDR_RLOCK(ifp);
   1765         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
   1766             if (ifa->ifa_addr->sa_family != addr->sa_family)
   1767                 continue;
   1768             if (sa_equal(addr, ifa->ifa_addr)) {  // Two IP address different
   1769                 if (getref)
   1770                     ifa_ref(ifa);
   1771                 IF_ADDR_RUNLOCK(ifp);
   1772                 goto done;
   1773             }
   1774             /* IP6 doesn't have broadcast */
   1775             if ((ifp->if_flags & IFF_BROADCAST) &&
   1776                 ifa->ifa_broadaddr &&
   1777                 ifa->ifa_broadaddr->sa_len != 0 &&
   1778                 sa_equal(ifa->ifa_broadaddr, addr)) {
   1779                 if (getref)
   1780                     ifa_ref(ifa);
   1781                 IF_ADDR_RUNLOCK(ifp);
   1782                 goto done;
   1783             }
   1784         }
   1785         IF_ADDR_RUNLOCK(ifp);
   1786     }
   1787     ifa = NULL;
   1788 done:
   1789     IFNET_RUNLOCK_NOSLEEP();
   1790     return (ifa);
   1791 }

• addr is fe80::fd98:f6de:1d5f:6c33
• ifa->ifa_addr is fe80:2::fd98:f6de:1d5f:6c33