diff options
author | Fabien Chouteau <chouteau@adacore.com> | 2011-08-01 18:18:37 +0200 |
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committer | Jan Kiszka <jan.kiszka@siemens.com> | 2011-08-03 12:57:11 +0200 |
commit | 551f237961f68eb72880cc4842bd72740585c2d3 (patch) | |
tree | c29cb2f2166dcbcc594de8e436280ca305efedde /slirp.c | |
parent | 76069087c923d8bbf168c8fb02a704928f958cb0 (diff) | |
download | slirp-551f237961f68eb72880cc4842bd72740585c2d3.zip slirp-551f237961f68eb72880cc4842bd72740585c2d3.tar.gz slirp-551f237961f68eb72880cc4842bd72740585c2d3.tar.bz2 |
Delayed IP packets
In the current implementation, if Slirp tries to send an IP packet to a client
with an unknown hardware address, the packet is simply dropped and an ARP
request is sent (if_encap in slirp/slirp.c).
With this patch, Slirp will send the ARP request, re-queue the packet and try
to send it later. The packet is dropped after one second if the ARP reply is
not received.
Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Diffstat (limited to 'slirp.c')
-rw-r--r-- | slirp.c | 72 |
1 files changed, 40 insertions, 32 deletions
@@ -689,55 +689,63 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) } } -/* output the IP packet to the ethernet device */ -void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) +/* Output the IP packet to the ethernet device. Returns 0 if the packet must be + * re-queued. + */ +int if_encap(Slirp *slirp, struct mbuf *ifm) { uint8_t buf[1600]; struct ethhdr *eh = (struct ethhdr *)buf; uint8_t ethaddr[ETH_ALEN]; - const struct ip *iph = (const struct ip *)ip_data; + const struct ip *iph = (const struct ip *)ifm->m_data; - if (ip_data_len + ETH_HLEN > sizeof(buf)) - return; + if (ifm->m_len + ETH_HLEN > sizeof(buf)) { + return 1; + } if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; struct ethhdr *reh = (struct ethhdr *)arp_req; struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); - /* If the client addr is not known, there is no point in - sending the packet to it. Normally the sender should have - done an ARP request to get its MAC address. Here we do it - in place of sending the packet and we hope that the sender - will retry sending its packet. */ - memset(reh->h_dest, 0xff, ETH_ALEN); - memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4); - memcpy(&reh->h_source[2], &slirp->vhost_addr, 4); - reh->h_proto = htons(ETH_P_ARP); - rah->ar_hrd = htons(1); - rah->ar_pro = htons(ETH_P_IP); - rah->ar_hln = ETH_ALEN; - rah->ar_pln = 4; - rah->ar_op = htons(ARPOP_REQUEST); - /* source hw addr */ - memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4); - memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4); - /* source IP */ - rah->ar_sip = slirp->vhost_addr.s_addr; - /* target hw addr (none) */ - memset(rah->ar_tha, 0, ETH_ALEN); - /* target IP */ - rah->ar_tip = iph->ip_dst.s_addr; - slirp->client_ipaddr = iph->ip_dst; - slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); + if (!ifm->arp_requested) { + /* If the client addr is not known, send an ARP request */ + memset(reh->h_dest, 0xff, ETH_ALEN); + memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4); + memcpy(&reh->h_source[2], &slirp->vhost_addr, 4); + reh->h_proto = htons(ETH_P_ARP); + rah->ar_hrd = htons(1); + rah->ar_pro = htons(ETH_P_IP); + rah->ar_hln = ETH_ALEN; + rah->ar_pln = 4; + rah->ar_op = htons(ARPOP_REQUEST); + + /* source hw addr */ + memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4); + memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4); + + /* source IP */ + rah->ar_sip = slirp->vhost_addr.s_addr; + + /* target hw addr (none) */ + memset(rah->ar_tha, 0, ETH_ALEN); + + /* target IP */ + rah->ar_tip = iph->ip_dst.s_addr; + slirp->client_ipaddr = iph->ip_dst; + slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); + ifm->arp_requested = true; + } + return 0; } else { memcpy(eh->h_dest, ethaddr, ETH_ALEN); memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); /* XXX: not correct */ memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); eh->h_proto = htons(ETH_P_IP); - memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); - slirp_output(slirp->opaque, buf, ip_data_len + ETH_HLEN); + memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len); + slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN); + return 1; } } |