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);
}
