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- #include "u.h"
- #include "../port/lib.h"
- #include "mem.h"
- #include "dat.h"
- #include "fns.h"
- #include "../port/error.h"
- #include "ip.h"
- typedef struct Icmp {
- uchar vihl; /* Version and header length */
- uchar tos; /* Type of service */
- uchar length[2]; /* packet length */
- uchar id[2]; /* Identification */
- uchar frag[2]; /* Fragment information */
- uchar ttl; /* Time to live */
- uchar proto; /* Protocol */
- uchar ipcksum[2]; /* Header checksum */
- uchar src[4]; /* Ip source */
- uchar dst[4]; /* Ip destination */
- uchar type;
- uchar code;
- uchar cksum[2];
- uchar icmpid[2];
- uchar seq[2];
- uchar data[1];
- } Icmp;
- enum { /* Packet Types */
- EchoReply = 0,
- Unreachable = 3,
- SrcQuench = 4,
- Redirect = 5,
- EchoRequest = 8,
- TimeExceed = 11,
- InParmProblem = 12,
- Timestamp = 13,
- TimestampReply = 14,
- InfoRequest = 15,
- InfoReply = 16,
- AddrMaskRequest = 17,
- AddrMaskReply = 18,
- Maxtype = 18,
- };
- enum
- {
- MinAdvise = 24, /* minimum needed for us to advise another protocol */
- };
- char *icmpnames[Maxtype+1] =
- {
- [EchoReply] "EchoReply",
- [Unreachable] "Unreachable",
- [SrcQuench] "SrcQuench",
- [Redirect] "Redirect",
- [EchoRequest] "EchoRequest",
- [TimeExceed] "TimeExceed",
- [InParmProblem] "InParmProblem",
- [Timestamp] "Timestamp",
- [TimestampReply] "TimestampReply",
- [InfoRequest] "InfoRequest",
- [InfoReply] "InfoReply",
- [AddrMaskRequest] "AddrMaskRequest",
- [AddrMaskReply ] "AddrMaskReply ",
- };
- enum {
- IP_ICMPPROTO = 1,
- ICMP_IPSIZE = 20,
- ICMP_HDRSIZE = 8,
- };
- enum
- {
- InMsgs,
- InErrors,
- OutMsgs,
- CsumErrs,
- LenErrs,
- HlenErrs,
- Nstats,
- };
- static char *statnames[Nstats] =
- {
- [InMsgs] "InMsgs",
- [InErrors] "InErrors",
- [OutMsgs] "OutMsgs",
- [CsumErrs] "CsumErrs",
- [LenErrs] "LenErrs",
- [HlenErrs] "HlenErrs",
- };
- typedef struct Icmppriv Icmppriv;
- struct Icmppriv
- {
- ulong stats[Nstats];
- /* message counts */
- ulong in[Maxtype+1];
- ulong out[Maxtype+1];
- };
- static void icmpkick(void *x, Block*);
- static void
- icmpcreate(Conv *c)
- {
- c->rq = qopen(64*1024, Qmsg, 0, c);
- c->wq = qbypass(icmpkick, c);
- }
- extern char*
- icmpconnect(Conv *c, char **argv, int argc)
- {
- char *e;
- e = Fsstdconnect(c, argv, argc);
- if(e != nil)
- return e;
- Fsconnected(c, e);
- return nil;
- }
- extern int
- icmpstate(Conv *c, char *state, int n)
- {
- USED(c);
- return snprint(state, n, "%s", "Datagram");
- }
- extern char*
- icmpannounce(Conv *c, char **argv, int argc)
- {
- char *e;
- e = Fsstdannounce(c, argv, argc);
- if(e != nil)
- return e;
- Fsconnected(c, nil);
- return nil;
- }
- extern void
- icmpclose(Conv *c)
- {
- qclose(c->rq);
- qclose(c->wq);
- ipmove(c->laddr, IPnoaddr);
- ipmove(c->raddr, IPnoaddr);
- c->lport = 0;
- }
- static void
- icmpkick(void *x, Block *bp)
- {
- Conv *c = x;
- Icmp *p;
- Icmppriv *ipriv;
- if(bp == nil)
- return;
- if(blocklen(bp) < ICMP_IPSIZE + ICMP_HDRSIZE){
- freeblist(bp);
- return;
- }
- p = (Icmp *)(bp->rp);
- p->vihl = IP_VER4;
- ipriv = c->p->priv;
- if(p->type <= Maxtype)
- ipriv->out[p->type]++;
-
- v6tov4(p->dst, c->raddr);
- v6tov4(p->src, c->laddr);
- p->proto = IP_ICMPPROTO;
- hnputs(p->icmpid, c->lport);
- memset(p->cksum, 0, sizeof(p->cksum));
- hnputs(p->cksum, ptclcsum(bp, ICMP_IPSIZE, blocklen(bp) - ICMP_IPSIZE));
- ipriv->stats[OutMsgs]++;
- ipoput4(c->p->f, bp, 0, c->ttl, c->tos);
- }
- extern void
- icmpttlexceeded(Fs *f, uchar *ia, Block *bp)
- {
- Block *nbp;
- Icmp *p, *np;
- p = (Icmp *)bp->rp;
- netlog(f, Logicmp, "sending icmpttlexceeded -> %V\n", p->src);
- nbp = allocb(ICMP_IPSIZE + ICMP_HDRSIZE + ICMP_IPSIZE + 8);
- nbp->wp += ICMP_IPSIZE + ICMP_HDRSIZE + ICMP_IPSIZE + 8;
- np = (Icmp *)nbp->rp;
- np->vihl = IP_VER4;
- memmove(np->dst, p->src, sizeof(np->dst));
- v6tov4(np->src, ia);
- memmove(np->data, bp->rp, ICMP_IPSIZE + 8);
- np->type = TimeExceed;
- np->code = 0;
- np->proto = IP_ICMPPROTO;
- hnputs(np->icmpid, 0);
- hnputs(np->seq, 0);
- memset(np->cksum, 0, sizeof(np->cksum));
- hnputs(np->cksum, ptclcsum(nbp, ICMP_IPSIZE, blocklen(nbp) - ICMP_IPSIZE));
- ipoput4(f, nbp, 0, MAXTTL, DFLTTOS);
- }
- static void
- icmpunreachable(Fs *f, Block *bp, int code, int seq)
- {
- Block *nbp;
- Icmp *p, *np;
- int i;
- uchar addr[IPaddrlen];
- p = (Icmp *)bp->rp;
- /* only do this for unicast sources and destinations */
- v4tov6(addr, p->dst);
- i = ipforme(f, addr);
- if((i&Runi) == 0)
- return;
- v4tov6(addr, p->src);
- i = ipforme(f, addr);
- if(i != 0 && (i&Runi) == 0)
- return;
- netlog(f, Logicmp, "sending icmpnoconv -> %V\n", p->src);
- nbp = allocb(ICMP_IPSIZE + ICMP_HDRSIZE + ICMP_IPSIZE + 8);
- nbp->wp += ICMP_IPSIZE + ICMP_HDRSIZE + ICMP_IPSIZE + 8;
- np = (Icmp *)nbp->rp;
- np->vihl = IP_VER4;
- memmove(np->dst, p->src, sizeof(np->dst));
- memmove(np->src, p->dst, sizeof(np->src));
- memmove(np->data, bp->rp, ICMP_IPSIZE + 8);
- np->type = Unreachable;
- np->code = code;
- np->proto = IP_ICMPPROTO;
- hnputs(np->icmpid, 0);
- hnputs(np->seq, seq);
- memset(np->cksum, 0, sizeof(np->cksum));
- hnputs(np->cksum, ptclcsum(nbp, ICMP_IPSIZE, blocklen(nbp) - ICMP_IPSIZE));
- ipoput4(f, nbp, 0, MAXTTL, DFLTTOS);
- }
- extern void
- icmpnoconv(Fs *f, Block *bp)
- {
- icmpunreachable(f, bp, 3, 0);
- }
- extern void
- icmpcantfrag(Fs *f, Block *bp, int mtu)
- {
- icmpunreachable(f, bp, 4, mtu);
- }
- static void
- goticmpkt(Proto *icmp, Block *bp)
- {
- Conv **c, *s;
- Icmp *p;
- uchar dst[IPaddrlen];
- ushort recid;
- p = (Icmp *) bp->rp;
- v4tov6(dst, p->src);
- recid = nhgets(p->icmpid);
- for(c = icmp->conv; *c; c++) {
- s = *c;
- if(s->lport == recid)
- if(ipcmp(s->raddr, dst) == 0){
- bp = concatblock(bp);
- if(bp != nil)
- qpass(s->rq, bp);
- return;
- }
- }
- freeblist(bp);
- }
- static Block *
- mkechoreply(Block *bp)
- {
- Icmp *q;
- uchar ip[4];
- q = (Icmp *)bp->rp;
- q->vihl = IP_VER4;
- memmove(ip, q->src, sizeof(q->dst));
- memmove(q->src, q->dst, sizeof(q->src));
- memmove(q->dst, ip, sizeof(q->dst));
- q->type = EchoReply;
- memset(q->cksum, 0, sizeof(q->cksum));
- hnputs(q->cksum, ptclcsum(bp, ICMP_IPSIZE, blocklen(bp) - ICMP_IPSIZE));
- return bp;
- }
- static char *unreachcode[] =
- {
- [0] "net unreachable",
- [1] "host unreachable",
- [2] "protocol unreachable",
- [3] "port unreachable",
- [4] "fragmentation needed and DF set",
- [5] "source route failed",
- };
- static void
- icmpiput(Proto *icmp, Ipifc*, Block *bp)
- {
- int n, iplen;
- Icmp *p;
- Block *r;
- Proto *pr;
- char *msg;
- char m2[128];
- Icmppriv *ipriv;
- ipriv = icmp->priv;
-
- ipriv->stats[InMsgs]++;
- p = (Icmp *)bp->rp;
- netlog(icmp->f, Logicmp, "icmpiput %d %d\n", p->type, p->code);
- n = blocklen(bp);
- if(n < ICMP_IPSIZE+ICMP_HDRSIZE){
- ipriv->stats[InErrors]++;
- ipriv->stats[HlenErrs]++;
- netlog(icmp->f, Logicmp, "icmp hlen %d\n", n);
- goto raise;
- }
- iplen = nhgets(p->length);
- if(iplen > n || (iplen % 1)){
- ipriv->stats[LenErrs]++;
- ipriv->stats[InErrors]++;
- netlog(icmp->f, Logicmp, "icmp length %d\n", iplen);
- goto raise;
- }
- if(ptclcsum(bp, ICMP_IPSIZE, iplen - ICMP_IPSIZE)){
- ipriv->stats[InErrors]++;
- ipriv->stats[CsumErrs]++;
- netlog(icmp->f, Logicmp, "icmp checksum error\n");
- goto raise;
- }
- if(p->type <= Maxtype)
- ipriv->in[p->type]++;
- switch(p->type) {
- case EchoRequest:
- if (iplen < n)
- bp = trimblock(bp, 0, iplen);
- r = mkechoreply(bp);
- ipriv->out[EchoReply]++;
- ipoput4(icmp->f, r, 0, MAXTTL, DFLTTOS);
- break;
- case Unreachable:
- if(p->code > 5 || p->code < 0)
- msg = unreachcode[1];
- else
- msg = unreachcode[p->code];
- bp->rp += ICMP_IPSIZE+ICMP_HDRSIZE;
- if(blocklen(bp) < MinAdvise){
- ipriv->stats[LenErrs]++;
- goto raise;
- }
- p = (Icmp *)bp->rp;
- pr = Fsrcvpcolx(icmp->f, p->proto);
- if(pr != nil && pr->advise != nil) {
- (*pr->advise)(pr, bp, msg);
- return;
- }
- bp->rp -= ICMP_IPSIZE+ICMP_HDRSIZE;
- goticmpkt(icmp, bp);
- break;
- case TimeExceed:
- if(p->code == 0){
- sprint(m2, "ttl exceeded at %V", p->src);
- bp->rp += ICMP_IPSIZE+ICMP_HDRSIZE;
- if(blocklen(bp) < MinAdvise){
- ipriv->stats[LenErrs]++;
- goto raise;
- }
- p = (Icmp *)bp->rp;
- pr = Fsrcvpcolx(icmp->f, p->proto);
- if(pr != nil && pr->advise != nil) {
- (*pr->advise)(pr, bp, m2);
- return;
- }
- bp->rp -= ICMP_IPSIZE+ICMP_HDRSIZE;
- }
- goticmpkt(icmp, bp);
- break;
- default:
- goticmpkt(icmp, bp);
- break;
- }
- return;
- raise:
- freeblist(bp);
- }
- void
- icmpadvise(Proto *icmp, Block *bp, char *msg)
- {
- Conv **c, *s;
- Icmp *p;
- uchar dst[IPaddrlen];
- ushort recid;
- p = (Icmp *) bp->rp;
- v4tov6(dst, p->dst);
- recid = nhgets(p->icmpid);
- for(c = icmp->conv; *c; c++) {
- s = *c;
- if(s->lport == recid)
- if(ipcmp(s->raddr, dst) == 0){
- qhangup(s->rq, msg);
- qhangup(s->wq, msg);
- break;
- }
- }
- freeblist(bp);
- }
- int
- icmpstats(Proto *icmp, char *buf, int len)
- {
- Icmppriv *priv;
- char *p, *e;
- int i;
- priv = icmp->priv;
- p = buf;
- e = p+len;
- for(i = 0; i < Nstats; i++)
- p = seprint(p, e, "%s: %lud\n", statnames[i], priv->stats[i]);
- for(i = 0; i <= Maxtype; i++){
- if(icmpnames[i])
- p = seprint(p, e, "%s: %lud %lud\n", icmpnames[i], priv->in[i], priv->out[i]);
- else
- p = seprint(p, e, "%d: %lud %lud\n", i, priv->in[i], priv->out[i]);
- }
- return p - buf;
- }
-
- void
- icmpinit(Fs *fs)
- {
- Proto *icmp;
- icmp = smalloc(sizeof(Proto));
- icmp->priv = smalloc(sizeof(Icmppriv));
- icmp->name = "icmp";
- icmp->connect = icmpconnect;
- icmp->announce = icmpannounce;
- icmp->state = icmpstate;
- icmp->create = icmpcreate;
- icmp->close = icmpclose;
- icmp->rcv = icmpiput;
- icmp->stats = icmpstats;
- icmp->ctl = nil;
- icmp->advise = icmpadvise;
- icmp->gc = nil;
- icmp->ipproto = IP_ICMPPROTO;
- icmp->nc = 16;
- icmp->ptclsize = 0;
- Fsproto(fs, icmp);
- }
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