/*
* randomly don't send packets
*/
static void
doipoput(Conv *c, Fs *f, Block *bp, int x, int ttl, int tos)
{
Rudpcb *ucb;
ucb = (Rudpcb*)c->ptcl;
if(ucb->randdrop && nrand(100) < ucb->randdrop)
freeblist(bp);
else
ipoput4(f, bp, x, ttl, tos, nil);
}
static void
grekick(void *x, Block *bp)
{
Conv *c = x;
GREhdr *ghp;
uchar laddr[IPaddrlen], raddr[IPaddrlen];
if(bp == nil)
return;
/* Make space to fit ip header (gre header already there) */
bp = padblock(bp, GRE_IPONLY);
if(bp == nil)
return;
/* make sure the message has a GRE header */
bp = pullupblock(bp, GRE_IPONLY+GRE_IPPLUSGRE);
if(bp == nil)
return;
ghp = (GREhdr *)(bp->rp);
ghp->vihl = IP_VER4;
if(!((GREpriv*)c->p->priv)->raw){
v4tov6(raddr, ghp->dst);
if(ipcmp(raddr, v4prefix) == 0)
memmove(ghp->dst, c->raddr + IPv4off, IPv4addrlen);
v4tov6(laddr, ghp->src);
if(ipcmp(laddr, v4prefix) == 0){
if(ipcmp(c->laddr, IPnoaddr) == 0)
findlocalip(c->p->f, c->laddr, raddr); /* pick interface closest to dest */
memmove(ghp->src, c->laddr + IPv4off, IPv4addrlen);
}
hnputs(ghp->eproto, c->rport);
}
ghp->proto = IP_GREPROTO;
ghp->frag[0] = 0;
ghp->frag[1] = 0;
ipoput4(c->p->f, bp, 0, c->ttl, c->tos, nil);
}
void
igmpsendreport(Medium *m, uchar *addr)
{
IGMPpkt *p;
Block *bp;
bp = allocb(sizeof(IGMPpkt));
if(bp == nil)
return;
p = (IGMPpkt*)bp->wp;
p->vihl = IP_VER4;
bp->wp += IGMPPKTSZ;
memset(bp->rp, 0, IGMPPKTSZ);
hnputl(p->src, Mediumgetaddr(m));
hnputl(p->dst, Ipallsys);
p->vertype = (1<<4) | IGMPreport;
p->proto = IP_IGMPPROTO;
memmove(p->group, addr, IPaddrlen);
hnputs(p->igmpcksum, ptclcsum(bp, IGMP_IPHDRSIZE, IGMP_HDRSIZE));
netlog(Logigmp, "igmpreport %I\n", p->group);
stats.outreports++;
ipoput4(bp, 0, 1, DFLTTOS, nil); /* TTL of 1 */
}
void udpkick(void *x, struct block *bp)
{
struct conv *c = x;
Udp4hdr *uh4;
Udp6hdr *uh6;
uint16_t rport;
uint8_t laddr[IPaddrlen], raddr[IPaddrlen];
Udpcb *ucb;
int dlen, ptcllen;
Udppriv *upriv;
struct Fs *f;
int version;
struct conv *rc;
upriv = c->p->priv;
assert(upriv);
f = c->p->f;
netlog(c->p->f, Logudp, "udp: kick\n");
if (bp == NULL)
return;
ucb = (Udpcb *) c->ptcl;
switch (ucb->headers) {
case 7:
/* get user specified addresses */
bp = pullupblock(bp, UDP_USEAD7);
if (bp == NULL)
return;
ipmove(raddr, bp->rp);
bp->rp += IPaddrlen;
ipmove(laddr, bp->rp);
bp->rp += IPaddrlen;
/* pick interface closest to dest */
if (ipforme(f, laddr) != Runi)
findlocalip(f, laddr, raddr);
bp->rp += IPaddrlen; /* Ignore ifc address */
rport = nhgets(bp->rp);
bp->rp += 2 + 2; /* Ignore local port */
break;
case 6:
/* get user specified addresses */
bp = pullupblock(bp, UDP_USEAD6);
if (bp == NULL)
return;
ipmove(raddr, bp->rp);
bp->rp += IPaddrlen;
ipmove(laddr, bp->rp);
bp->rp += IPaddrlen;
/* pick interface closest to dest */
if (ipforme(f, laddr) != Runi)
findlocalip(f, laddr, raddr);
rport = nhgets(bp->rp);
bp->rp += 2 + 2; /* Ignore local port */
break;
default:
rport = 0;
break;
}
if (ucb->headers) {
if (memcmp(laddr, v4prefix, IPv4off) == 0 ||
ipcmp(laddr, IPnoaddr) == 0)
version = V4;
else
version = V6;
} else {
if ((memcmp(c->raddr, v4prefix, IPv4off) == 0 &&
memcmp(c->laddr, v4prefix, IPv4off) == 0)
|| ipcmp(c->raddr, IPnoaddr) == 0)
version = V4;
else
version = V6;
}
dlen = blocklen(bp);
/* fill in pseudo header and compute checksum */
switch (version) {
case V4:
bp = padblock(bp, UDP4_IPHDR_SZ + UDP_UDPHDR_SZ);
if (bp == NULL)
return;
uh4 = (Udp4hdr *) (bp->rp);
ptcllen = dlen + UDP_UDPHDR_SZ;
uh4->Unused = 0;
uh4->udpproto = IP_UDPPROTO;
uh4->frag[0] = 0;
uh4->frag[1] = 0;
hnputs(uh4->udpplen, ptcllen);
if (ucb->headers) {
v6tov4(uh4->udpdst, raddr);
hnputs(uh4->udpdport, rport);
v6tov4(uh4->udpsrc, laddr);
rc = NULL;
} else {
v6tov4(uh4->udpdst, c->raddr);
hnputs(uh4->udpdport, c->rport);
if (ipcmp(c->laddr, IPnoaddr) == 0)
findlocalip(f, c->laddr, c->raddr);
v6tov4(uh4->udpsrc, c->laddr);
rc = c;
}
hnputs(uh4->udpsport, c->lport);
hnputs(uh4->udplen, ptcllen);
uh4->udpcksum[0] = 0;
uh4->udpcksum[1] = 0;
hnputs(uh4->udpcksum,
~ptclcsum(bp, UDP4_PHDR_OFF, UDP4_PHDR_SZ));
bp->checksum_start = UDP4_IPHDR_SZ;
bp->checksum_offset = uh4->udpcksum - uh4->udpsport;
bp->flag |= Budpck;
uh4->vihl = IP_VER4;
ipoput4(f, bp, 0, c->ttl, c->tos, rc);
break;
case V6:
bp = padblock(bp, UDP6_IPHDR_SZ + UDP_UDPHDR_SZ);
if (bp == NULL)
return;
// using the v6 ip header to create pseudo header
// first then reset it to the normal ip header
uh6 = (Udp6hdr *) (bp->rp);
memset(uh6, 0, 8);
ptcllen = dlen + UDP_UDPHDR_SZ;
hnputl(uh6->viclfl, ptcllen);
uh6->hoplimit = IP_UDPPROTO;
if (ucb->headers) {
ipmove(uh6->udpdst, raddr);
hnputs(uh6->udpdport, rport);
ipmove(uh6->udpsrc, laddr);
rc = NULL;
} else {
ipmove(uh6->udpdst, c->raddr);
hnputs(uh6->udpdport, c->rport);
if (ipcmp(c->laddr, IPnoaddr) == 0)
findlocalip(f, c->laddr, c->raddr);
ipmove(uh6->udpsrc, c->laddr);
rc = c;
}
hnputs(uh6->udpsport, c->lport);
hnputs(uh6->udplen, ptcllen);
uh6->udpcksum[0] = 0;
uh6->udpcksum[1] = 0;
hnputs(uh6->udpcksum,
ptclcsum(bp, UDP6_PHDR_OFF,
dlen + UDP_UDPHDR_SZ + UDP6_PHDR_SZ));
memset(uh6, 0, 8);
uh6->viclfl[0] = IP_VER6;
hnputs(uh6->len, ptcllen);
uh6->nextheader = IP_UDPPROTO;
ipoput6(f, bp, 0, c->ttl, c->tos, rc);
break;
default:
panic("udpkick: version %d", version);
}
upriv->ustats.udpOutDatagrams++;
}
/*
* encapsulate next IP packet on x's write queue in IP/ESP packet
* and initiate output of the result.
*/
static void
espkick(void *x)
{
int nexthdr, payload, pad, align;
uint8_t *auth;
Block *bp;
Conv *c = x;
Esp4hdr *eh4;
Esp6hdr *eh6;
Espcb *ecb;
Esptail *et;
Userhdr *uh;
Versdep vers;
getverslens(convipvers(c), &vers);
bp = qget(c->wq);
if(bp == nil)
return;
qlock(c);
ecb = c->ptcl;
if(ecb->header) {
/* make sure the message has a User header */
bp = pullupblock(bp, Userhdrlen);
if(bp == nil) {
qunlock(c);
return;
}
uh = (Userhdr*)bp->rp;
nexthdr = uh->nexthdr;
bp->rp += Userhdrlen;
} else {
nexthdr = 0; /* what should this be? */
}
payload = BLEN(bp) + ecb->espivlen;
/* Make space to fit ip header */
bp = padblock(bp, vers.hdrlen + ecb->espivlen);
getpktspiaddrs(bp->rp, &vers);
align = 4;
if(ecb->espblklen > align)
align = ecb->espblklen;
if(align % ecb->ahblklen != 0)
panic("espkick: ahblklen is important after all");
pad = (align-1) - (payload + Esptaillen-1)%align;
/*
* Make space for tail
* this is done by calling padblock with a negative size
* Padblock does not change bp->wp!
*/
bp = padblock(bp, -(pad+Esptaillen+ecb->ahlen));
bp->wp += pad+Esptaillen+ecb->ahlen;
et = (Esptail*)(bp->rp + vers.hdrlen + payload + pad);
/* fill in tail */
et->pad = pad;
et->nexthdr = nexthdr;
/* encrypt the payload */
ecb->cipher(ecb, bp->rp + vers.hdrlen, payload + pad + Esptaillen);
auth = bp->rp + vers.hdrlen + payload + pad + Esptaillen;
/* fill in head; construct a new IP header and an ESP header */
if (vers.version == V4) {
eh4 = (Esp4hdr *)bp->rp;
eh4->vihl = IP_VER4;
v6tov4(eh4->espsrc, c->laddr);
v6tov4(eh4->espdst, c->raddr);
eh4->espproto = IP_ESPPROTO;
eh4->frag[0] = 0;
eh4->frag[1] = 0;
hnputl(eh4->espspi, ecb->spi);
hnputl(eh4->espseq, ++ecb->seq);
} else {
eh6 = (Esp6hdr *)bp->rp;
eh6->vcf[0] = IP_VER6;
ipmove(eh6->src, c->laddr);
ipmove(eh6->dst, c->raddr);
eh6->proto = IP_ESPPROTO;
hnputl(eh6->espspi, ecb->spi);
hnputl(eh6->espseq, ++ecb->seq);
}
/* compute secure hash */
ecb->auth(ecb, bp->rp + vers.iphdrlen, (vers.hdrlen - vers.iphdrlen) +
payload + pad + Esptaillen, auth);
qunlock(c);
/* print("esp: pass down: %uld\n", BLEN(bp)); */
if (vers.version == V4)
ipoput4(c->p->f, bp, 0, c->ttl, c->tos, c);
else
ipoput6(c->p->f, bp, 0, c->ttl, c->tos, c);
}
static void
espkick(void *x)
{
Conv *c = x;
Esphdr *eh;
Esptail *et;
Userhdr *uh;
Espcb *ecb;
Block *bp;
int nexthdr;
int payload;
int pad;
int align;
uchar *auth;
bp = qget(c->wq);
if(bp == nil)
return;
qlock(c);
ecb = c->ptcl;
if(ecb->header) {
/* make sure the message has a User header */
bp = pullupblock(bp, UserhdrSize);
if(bp == nil) {
qunlock(c);
return;
}
uh = (Userhdr*)bp->rp;
nexthdr = uh->nexthdr;
bp->rp += UserhdrSize;
} else {
nexthdr = 0; // what should this be?
}
payload = BLEN(bp) + ecb->espivlen;
/* Make space to fit ip header */
bp = padblock(bp, EsphdrSize + ecb->espivlen);
align = 4;
if(ecb->espblklen > align)
align = ecb->espblklen;
if(align % ecb->ahblklen != 0)
panic("espkick: ahblklen is important after all");
pad = (align-1) - (payload + EsptailSize-1)%align;
/*
* Make space for tail
* this is done by calling padblock with a negative size
* Padblock does not change bp->wp!
*/
bp = padblock(bp, -(pad+EsptailSize+ecb->ahlen));
bp->wp += pad+EsptailSize+ecb->ahlen;
eh = (Esphdr *)(bp->rp);
et = (Esptail*)(bp->rp + EsphdrSize + payload + pad);
// fill in tail
et->pad = pad;
et->nexthdr = nexthdr;
ecb->cipher(ecb, bp->rp+EsphdrSize, payload+pad+EsptailSize);
auth = bp->rp + EsphdrSize + payload + pad + EsptailSize;
// fill in head
eh->vihl = IP_VER4;
hnputl(eh->espspi, ecb->spi);
hnputl(eh->espseq, ++ecb->seq);
v6tov4(eh->espsrc, c->laddr);
v6tov4(eh->espdst, c->raddr);
eh->espproto = IP_ESPPROTO;
eh->frag[0] = 0;
eh->frag[1] = 0;
ecb->auth(ecb, bp->rp+IphdrSize, (EsphdrSize-IphdrSize)+payload+pad+EsptailSize, auth);
qunlock(c);
//print("esp: pass down: %uld\n", BLEN(bp));
ipoput4(c->p->f, bp, 0, c->ttl, c->tos, c);
}
