Function sctp_send_resp_msg

freebsd/netinet/sctp_output.c:10991–11245

}

static void
sctp_send_resp_msg(struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, uint32_t vtag,
    uint8_t type, struct mbuf *cause,
    uint8_t mflowtype, uint32_t mflowid, uint16_t fibnum,
    uint32_t vrf_id, uint16_t port)
{
	struct mbuf *o_pak;
	struct mbuf *mout;
	struct sctphdr *shout;
	struct sctp_chunkhdr *ch;
#if defined(INET) || defined(INET6)
	struct udphdr *udp;
#endif
	int ret, len, cause_len, padding_len;
#ifdef INET
	struct sockaddr_in *src_sin, *dst_sin;
	struct ip *ip;
#endif
#ifdef INET6
	struct sockaddr_in6 *src_sin6, *dst_sin6;
	struct ip6_hdr *ip6;
#endif

	/* Compute the length of the cause and add final padding. */
	cause_len = 0;
	if (cause != NULL) {
		struct mbuf *m_at, *m_last = NULL;

		for (m_at = cause; m_at; m_at = SCTP_BUF_NEXT(m_at)) {
			if (SCTP_BUF_NEXT(m_at) == NULL)
				m_last = m_at;
			cause_len += SCTP_BUF_LEN(m_at);
		}
		padding_len = cause_len % 4;
		if (padding_len != 0) {
			padding_len = 4 - padding_len;
		}
		if (padding_len != 0) {
			if (sctp_add_pad_tombuf(m_last, padding_len) == NULL) {
				sctp_m_freem(cause);
				return;
			}
		}
	} else {
		padding_len = 0;
	}
	/* Get an mbuf for the header. */
	len = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr);
	switch (dst->sa_family) {
#ifdef INET
	case AF_INET:
		len += sizeof(struct ip);
		break;
#endif
#ifdef INET6
	case AF_INET6:
		len += sizeof(struct ip6_hdr);