c - How to send modified IPv6 packet through RAW socket? -

i'm trying send custom ipv6 header through raw socket in c linux.
succeded in ipv4 using ip_hdrincl socket option, however, there's not equivalent ipv6.
found workaround here suggesting use socket(af_inet6, sock_raw, ipproto_raw) have same effect enabling ip_hdrincl socket option.

socket created , i'm not getting error until use sendto function modified header.

i setup socket this:

static int socketfd = 0; static struct sockaddr_in6 remote;  int main() {     socketfd = socket (pf_inet6, sock_raw, ipproto_raw);      if (socketfd < 0)     {         printf ("an error ocurred while creating socket.\n");         exit (2);     }      remote.sin6_family = af_inet6;     remote.sin6_port = htons (25000);      if (inet_pton (af_inet6, "fd00:c0de::70d6:4ab9:115d:8cda", &(remote.sin6_addr)) != 1)     {         close (socketfd);         printf ("unable parse ipv6 address.\n");         exit (2);     }   /*more code */   ...    return 0; } 

and then, have callback function should send custom ipv6 packets sendto fails returning einval.

static void sendpacket () {     char buffer[bufsiz];     const size_t len = sizeof(struct ip6_hdr) + sizeof(struct udp_hdr);     struct ip6_hdr *ip6 = (struct ip6_hdr*) (buffer);     struct udp_hdr *udp = (struct udp_hdr *) (buffer + sizeof(struct ip6_hdr));      memset (buffer, 0, bufsiz);      ip6->ip6_ctlun.ip6_un2_vfc = 0x60;     ip6->ip6_dst = remote.sin6_addr;     ip6->ip6_flow = 60;     ip6->ip6_hops = 64;     ip6->ip6_nxt = 17;     ip6->ip6_plen = sizeof(struct udp_hdr);      if (inet_pton (af_inet6, "fd00:c0de::62a4:4cff:1234:5678", &(ip6->ip6_src)) != 1)     {         printf ("error while parsing spoofed ipv6 address.\n");         return;     }      // fabricate udp header. source port number, redundant     udp->uh_sport = htons (21000);     // destination port number     udp->uh_dport = remote.sin6_port;     udp->uh_ulen = htons (sizeof(struct udp_hdr));      if (sendto (socketfd, buffer, len, 0, (struct sockaddr *) &remote, sizeof(remote)) < 0)     {         perror ("sendto");         printf ("error while sending packet.\n");     } } 

i've debugged program , values in ip6_hdr struct seem correct , ones in struct udp_hdr. missing something?

ok, found solution. struggling this, way solved using pcap library (followed this example). must use af_packets, found complete example uses raw sockets accomplish in link.