diff options
| -rw-r--r-- | ospfd/ospf_packet.c | 137 |
1 files changed, 76 insertions, 61 deletions
diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c index 111ee099..5952d184 100644 --- a/ospfd/ospf_packet.c +++ b/ospfd/ospf_packet.c @@ -507,6 +507,70 @@ ospf_swab_iph_toh (struct ip *iph) iph->ip_id = ntohs(iph->ip_id); } +#ifdef WANT_OSPF_WRITE_FRAGMENT +void +ospf_write_frags (struct ospf_packet *op, struct ip *ip, struct msghdr *msg, + struct iovec *iov, int maxdatasize); +{ +#define OSPF_WRITE_FRAG_SHIFT 3 + + assert ( op->length == stream_get_endp(op->s) ); + + /* we can but try. + * + * SunOS, BSD and BSD derived kernels likely will clear ip_id, as + * well as the IP_MF flag, making this all quite pointless. + * + * However, for a system on which IP_MF is left alone, and ip_id left + * alone or else which sets same ip_id for each fragment this might + * work, eg linux. + * + * XXX-TODO: It would be much nicer to have the kernel's use their + * existing fragmentation support to do this for us. Bugs/RFEs need to + * be raised against the various kernels. + */ + + /* set More Frag */ + iph->ip_off |= IP_MF; + + /* ip frag offset is expressed in units of 8byte words */ + offset = maxdatasize >> OSPF_WRITE_FRAG_SHIFT; + + while ( (stream_get_endp(op->s) - stream_get_getp (op->s)) + > maxdatasize ) + { + /* data length of this frag is to next offset value */ + iov[1]->iov_len = offset << OSPF_WRITE_FRAG_SHIFT; + iph->ip_len = iov[1]->iov_len + sizeof (struct ip); + assert (iph->ip_len <= oi->ifp->mtu); + + ospf_swab_iph_ton (iph); + + ret = sendmsg (ospf->fd, msg, flags); + + ospf_swab_iph_toh (iph); + + if (ret < 0) + zlog_warn ("*** sendmsg in ospf_write to %s," + " id %d, off %d, len %d failed with %s", + inet_ntoa (iph->ip_dst), + iph->ip_id, + iph->ip_off, + iph->ip_len, + strerror (errno)); + + iph->ip_off += offset; + stream_forward (op->s, iov[1]->iov_len); + iov[1]->iov_base = STREAM_PNT (op->s); + } + + /* setup for final fragment */ + iov[1]->iov_len = stream_get_endp(op->s) - stream_get_getp (op->s); + iph->ip_len = iov[1]->iov_len + sizeof (struct ip); + iph->ip_off &= (~IP_MF); +} +#endif /* WANT_OSPF_WRITE_FRAGMENT */ + int ospf_write (struct thread *thread) { @@ -521,10 +585,11 @@ ospf_write (struct thread *thread) int ret; int flags = 0; struct listnode *node; +#ifdef WANT_OSPF_WRITE_FRAGMENT static u_int16_t ipid = 0; +#endif /* WANT_OSPF_WRITE_FRAGMENT */ u_int16_t maxdatasize, offset; #define OSPF_WRITE_IPHL_SHIFT 2 -#define OSPF_WRITE_FRAG_SHIFT 3 ospf->t_write = NULL; @@ -532,11 +597,13 @@ ospf_write (struct thread *thread) assert (node); oi = getdata (node); assert (oi); - + +#ifdef WANT_OSPF_WRITE_FRAGMENT /* seed ipid static with low order bits of time */ if (ipid == 0) ipid = (time(NULL) & 0xffff); - +#endif /* WANT_OSPF_WRITE_FRAGMENT */ + /* convenience - max OSPF data per packet */ maxdatasize = oi->ifp->mtu - sizeof (struct ip); @@ -578,14 +645,15 @@ ospf_write (struct thread *thread) iph.ip_v = IPVERSION; iph.ip_tos = IPTOS_PREC_INTERNETCONTROL; iph.ip_len = (iph.ip_hl << OSPF_WRITE_IPHL_SHIFT) + op->length; - iph.ip_id = 0; +#ifdef WANT_OSPF_WRITE_FRAGMENT /* XXX-MT: not thread-safe at all.. * XXX: this presumes this is only programme sending OSPF packets * otherwise, no guarantee ipid will be unique */ iph.ip_id = ++ipid; - +#endif /* WANT_OSPF_WRITE_FRAGMENT */ + iph.ip_off = 0; if (oi->type == OSPF_IFTYPE_VIRTUALLINK) iph.ip_ttl = OSPF_VL_IP_TTL; @@ -609,63 +677,10 @@ ospf_write (struct thread *thread) /* Sadly we can not rely on kernels to fragment packets because of either * IP_HDRINCL and/or multicast destination being set. */ +#ifdef WANT_OSPF_WRITE_FRAGMENT if ( op->length > maxdatasize ) - { - assert ( op->length == stream_get_endp(op->s) ); - - /* we can but try. - * - * SunOS, BSD and BSD derived kernels likely will clear ip_id, as - * well as the IP_MF flag, making this all quite pointless. - * - * However, for a system on which IP_MF is left alone, and ip_id left - * alone or else which sets same ip_id for each fragment this might - * work, eg linux. - * - * XXX-TODO: It would be much nicer to have the kernel's use their - * existing fragmentation support to do this for us. Bugs/RFEs need to - * be raised against the various kernels. - */ - - /* set More Frag */ - iph.ip_off |= IP_MF; - - /* ip frag offset is expressed in units of 8byte words */ - offset = maxdatasize >> OSPF_WRITE_FRAG_SHIFT; - - while ( (stream_get_endp(op->s) - stream_get_getp (op->s)) - > maxdatasize ) - { - /* data length of this frag is to next offset value */ - iov[1].iov_len = offset << OSPF_WRITE_FRAG_SHIFT; - iph.ip_len = iov[1].iov_len + sizeof (struct ip); - assert (iph.ip_len <= oi->ifp->mtu); - - ospf_swab_iph_ton (&iph); - - ret = sendmsg (ospf->fd, &msg, flags); - - ospf_swab_iph_toh (&iph); - - if (ret < 0) - zlog_warn ("*** sendmsg in ospf_write to %s," - " id %d, off %d, len %d failed with %s", - inet_ntoa (iph.ip_dst), - iph.ip_id, - iph.ip_off, - iph.ip_len, - strerror (errno)); - - iph.ip_off += offset; - stream_forward (op->s, iov[1].iov_len); - iov[1].iov_base = STREAM_PNT (op->s); - } - - /* setup for final fragment */ - iov[1].iov_len = stream_get_endp(op->s) - stream_get_getp (op->s); - iph.ip_len = iov[1].iov_len + sizeof (struct ip); - iph.ip_off &= (~IP_MF); - } + ospf_write_frags (&op, &ip, &msg, &iov, maxdatasize); +#endif /* WANT_OSPF_WRITE_FRAGMENT */ /* send final fragment (could be first) */ ospf_swab_iph_ton (&iph); |