Beispiel #1
0
/* Puts into 'b' a packet that flow_extract() would parse as having the given
 * 'flow'.
 *
 * (This is useful only for testing, obviously, and the packet isn't really
 * valid. It hasn't got some checksums filled in, for one, and lots of fields
 * are just zeroed.) */
void
flow_compose(struct ofpbuf *b, const struct flow *flow)
{
    eth_compose(b, flow->dl_dst, flow->dl_src, ntohs(flow->dl_type), 0);
    if (flow->dl_type == htons(FLOW_DL_TYPE_NONE)) {
        struct eth_header *eth = b->l2;
        eth->eth_type = htons(b->size);
        return;
    }

    if (flow->vlan_tci & htons(VLAN_CFI)) {
        eth_push_vlan(b, flow->vlan_tci);
    }

    if (flow->dl_type == htons(ETH_TYPE_IP)) {
        struct ip_header *ip;

        b->l3 = ip = ofpbuf_put_zeros(b, sizeof *ip);
        ip->ip_ihl_ver = IP_IHL_VER(5, 4);
        ip->ip_tos = flow->nw_tos;
        ip->ip_ttl = flow->nw_ttl;
        ip->ip_proto = flow->nw_proto;
        put_16aligned_be32(&ip->ip_src, flow->nw_src);
        put_16aligned_be32(&ip->ip_dst, flow->nw_dst);

        if (flow->nw_frag & FLOW_NW_FRAG_ANY) {
            ip->ip_frag_off |= htons(IP_MORE_FRAGMENTS);
            if (flow->nw_frag & FLOW_NW_FRAG_LATER) {
                ip->ip_frag_off |= htons(100);
            }
        }
        if (!(flow->nw_frag & FLOW_NW_FRAG_ANY)
            || !(flow->nw_frag & FLOW_NW_FRAG_LATER)) {
            if (flow->nw_proto == IPPROTO_TCP) {
                struct tcp_header *tcp;

                b->l4 = tcp = ofpbuf_put_zeros(b, sizeof *tcp);
                tcp->tcp_src = flow->tp_src;
                tcp->tcp_dst = flow->tp_dst;
                tcp->tcp_ctl = TCP_CTL(0, 5);
            } else if (flow->nw_proto == IPPROTO_UDP) {
                struct udp_header *udp;

                b->l4 = udp = ofpbuf_put_zeros(b, sizeof *udp);
                udp->udp_src = flow->tp_src;
                udp->udp_dst = flow->tp_dst;
            } else if (flow->nw_proto == IPPROTO_SCTP) {
                struct sctp_header *sctp;

                b->l4 = sctp = ofpbuf_put_zeros(b, sizeof *sctp);
                sctp->sctp_src = flow->tp_src;
                sctp->sctp_dst = flow->tp_dst;
            } else if (flow->nw_proto == IPPROTO_ICMP) {
                struct icmp_header *icmp;

                b->l4 = icmp = ofpbuf_put_zeros(b, sizeof *icmp);
                icmp->icmp_type = ntohs(flow->tp_src);
                icmp->icmp_code = ntohs(flow->tp_dst);
                icmp->icmp_csum = csum(icmp, ICMP_HEADER_LEN);
            }
        }

        ip = b->l3;
        ip->ip_tot_len = htons((uint8_t *) b->data + b->size
                               - (uint8_t *) b->l3);
        ip->ip_csum = csum(ip, sizeof *ip);
    } else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
        /* XXX */
    } else if (flow->dl_type == htons(ETH_TYPE_ARP) ||
               flow->dl_type == htons(ETH_TYPE_RARP)) {
        struct arp_eth_header *arp;

        b->l3 = arp = ofpbuf_put_zeros(b, sizeof *arp);
        arp->ar_hrd = htons(1);
        arp->ar_pro = htons(ETH_TYPE_IP);
        arp->ar_hln = ETH_ADDR_LEN;
        arp->ar_pln = 4;
        arp->ar_op = htons(flow->nw_proto);

        if (flow->nw_proto == ARP_OP_REQUEST ||
            flow->nw_proto == ARP_OP_REPLY) {
            put_16aligned_be32(&arp->ar_spa, flow->nw_src);
            put_16aligned_be32(&arp->ar_tpa, flow->nw_dst);
            memcpy(arp->ar_sha, flow->arp_sha, ETH_ADDR_LEN);
            memcpy(arp->ar_tha, flow->arp_tha, ETH_ADDR_LEN);
        }
    }

    if (eth_type_mpls(flow->dl_type)) {
        b->l2_5 = b->l3;
        push_mpls(b, flow->dl_type, flow->mpls_lse);
    }
}
/* Puts into 'b' a packet that flow_extract() would parse as having the given
 * 'flow'.
 *
 * (This is useful only for testing, obviously, and the packet isn't really
 * valid.  It hasn't got any checksums filled in, for one, and lots of fields
 * are just zeroed.) */
void
flow_compose(struct ofpbuf *b, const struct flow *flow)
{
    eth_compose(b, flow->dl_dst, flow->dl_src, ntohs(flow->dl_type), 0);
    if (flow->dl_type == htons(FLOW_DL_TYPE_NONE)) {
        struct eth_header *eth = b->l2;
        eth->eth_type = htons(b->size);
        return;
    }

    if (flow->vlan_tci & htons(VLAN_CFI)) {
        eth_push_vlan(b, flow->vlan_tci & ~htons(VLAN_CFI));
    }

    if (flow->dl_type == htons(ETH_TYPE_IP)) {
        struct ip_header *ip;

        b->l3 = ip = ofpbuf_put_zeros(b, sizeof *ip);
        ip->ip_ihl_ver = IP_IHL_VER(5, 4);
        ip->ip_tos = flow->nw_tos;
        ip->ip_proto = flow->nw_proto;
        ip->ip_src = flow->nw_src;
        ip->ip_dst = flow->nw_dst;

        if (flow->nw_frag & FLOW_NW_FRAG_ANY) {
            ip->ip_frag_off |= htons(IP_MORE_FRAGMENTS);
            if (flow->nw_frag & FLOW_NW_FRAG_LATER) {
                ip->ip_frag_off |= htons(100);
            }
        }
        if (!(flow->nw_frag & FLOW_NW_FRAG_ANY)
            || !(flow->nw_frag & FLOW_NW_FRAG_LATER)) {
            if (flow->nw_proto == IPPROTO_TCP) {
                struct tcp_header *tcp;

                b->l4 = tcp = ofpbuf_put_zeros(b, sizeof *tcp);
                tcp->tcp_src = flow->tp_src;
                tcp->tcp_dst = flow->tp_dst;
            } else if (flow->nw_proto == IPPROTO_UDP) {
                struct udp_header *udp;

                b->l4 = udp = ofpbuf_put_zeros(b, sizeof *udp);
                udp->udp_src = flow->tp_src;
                udp->udp_dst = flow->tp_dst;
            } else if (flow->nw_proto == IPPROTO_ICMP) {
                struct icmp_header *icmp;

                b->l4 = icmp = ofpbuf_put_zeros(b, sizeof *icmp);
                icmp->icmp_type = ntohs(flow->tp_src);
                icmp->icmp_code = ntohs(flow->tp_dst);
            }
        }
    } else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
        /* XXX */
    } else if (flow->dl_type == htons(ETH_TYPE_ARP)) {
        struct arp_eth_header *arp;

        b->l3 = arp = ofpbuf_put_zeros(b, sizeof *arp);
        arp->ar_hrd = htons(1);
        arp->ar_pro = htons(ETH_TYPE_IP);
        arp->ar_hln = ETH_ADDR_LEN;
        arp->ar_pln = 4;
        arp->ar_op = htons(flow->nw_proto);

        if (flow->nw_proto == ARP_OP_REQUEST ||
            flow->nw_proto == ARP_OP_REPLY) {
            arp->ar_spa = flow->nw_src;
            arp->ar_tpa = flow->nw_dst;
            memcpy(arp->ar_sha, flow->arp_sha, ETH_ADDR_LEN);
            memcpy(arp->ar_tha, flow->arp_tha, ETH_ADDR_LEN);
        }
    }
}