route.c

早期freebsd实现

	}
	if (forcehost)
		ishost = 1;
	if (forcenet)
		ishost = 0;
	flags |= RTF_UP;
	if (ishost)
		flags |= RTF_HOST;
	if (iflag == 0)
		flags |= RTF_GATEWAY;
	for (attempts = 1; ; attempts++) {
		errno = 0;
		if (Cflag && (af == AF_INET || af == AF_NS)) {
			route.rt_flags = flags;
			route.rt_dst = so_dst.sa;
			route.rt_gateway = so_gate.sa;
			if ((ret = ioctl(s, *cmd == 'a' ? SIOCADDRT : SIOCDELRT,
			     (caddr_t)&route)) == 0)
				break;
		} else {
		    if ((ret = rtmsg(*cmd, flags)) == 0)
				break;
		}
		if (errno != ENETUNREACH && errno != ESRCH)
			break;
		if (af == AF_INET && hp && hp->h_addr_list[1]) {
			hp->h_addr_list++;
			bcopy(hp->h_addr_list[0], (caddr_t)&so_dst.sin.sin_addr,
			    hp->h_length);
		} else
			break;
	}
	if (*cmd == 'g')
		exit(0);
	oerrno = errno;
	(void) printf("%s %s %s: gateway %s", cmd, ishost? "host" : "net",
		dest, gateway);
	if (attempts > 1 && ret == 0)
	    (void) printf(" (%s)",
		inet_ntoa(((struct sockaddr_in *)&route.rt_gateway)->sin_addr));
	if (ret == 0)
		(void) printf("\n");
	else {
		switch (oerrno) {
		case ESRCH:
			err = "not in table";
			break;
		case EBUSY:
			err = "entry in use";
			break;
		case ENOBUFS:
			err = "routing table overflow";
			break;
		default:
			err = strerror(oerrno);
			break;
		}
		(void) printf(": %s\n", err);
	}
}

void
inet_makenetandmask(net, sin)
	u_long net;
	register struct sockaddr_in *sin;
{
	u_long addr, mask = 0;
	register char *cp;

	rtm_addrs |= RTA_NETMASK;
	if (net == 0)
		mask = addr = 0;
	else if (net < 128) {
		addr = net << IN_CLASSA_NSHIFT;
		mask = IN_CLASSA_NET;
	} else if (net < 65536) {
		addr = net << IN_CLASSB_NSHIFT;
		mask = IN_CLASSB_NET;
	} else if (net < 16777216L) {
		addr = net << IN_CLASSC_NSHIFT;
		mask = IN_CLASSC_NET;
	} else {
		addr = net;
		if ((addr & IN_CLASSA_HOST) == 0)
			mask =  IN_CLASSA_NET;
		else if ((addr & IN_CLASSB_HOST) == 0)
			mask =  IN_CLASSB_NET;
		else if ((addr & IN_CLASSC_HOST) == 0)
			mask =  IN_CLASSC_NET;
		else
			mask = -1;
	}
	sin->sin_addr.s_addr = htonl(addr);
	sin = &so_mask.sin;
	sin->sin_addr.s_addr = htonl(mask);
	sin->sin_len = 0;
	sin->sin_family = 0;
	cp = (char *)(&sin->sin_addr + 1);
	while (*--cp == 0 && cp > (char *)sin)
		;
	sin->sin_len = 1 + cp - (char *)sin;
}

/*
 * Interpret an argument as a network address of some kind,
 * returning 1 if a host address, 0 if a network address.
 */
int
getaddr(which, s, hpp)
	int which;
	char *s;
	struct hostent **hpp;
{
	register sup su;
	struct ns_addr ns_addr();
	struct iso_addr *iso_addr();
	struct hostent *hp;
	struct netent *np;
	u_long val;

	if (af == 0) {
		af = AF_INET;
		aflen = sizeof(struct sockaddr_in);
	}
	rtm_addrs |= which;
	switch (which) {
	case RTA_DST:		su = so_addrs[0]; su->sa.sa_family = af; break;
	case RTA_GATEWAY:	su = so_addrs[1]; su->sa.sa_family = af; break;
	case RTA_NETMASK:	su = so_addrs[2]; break;
	case RTA_GENMASK:	su = so_addrs[3]; break;
	case RTA_IFP:		su = so_addrs[4]; su->sa.sa_family = af; break;
	case RTA_IFA:		su = so_addrs[5]; su->sa.sa_family = af; break;
	default:		usage("Internal Error"); /*NOTREACHED*/
	}
	su->sa.sa_len = aflen;
	if (strcmp(s, "default") == 0) {
		switch (which) {
		case RTA_DST:
			forcenet++;
			(void) getaddr(RTA_NETMASK, s, 0);
			break;
		case RTA_NETMASK:
		case RTA_GENMASK:
			su->sa.sa_len = 0;
		}
		return 0;
	}
	if (af == AF_NS)
		goto do_xns;
	if (af == AF_OSI)
		goto do_osi;
	if (af == AF_LINK)
		goto do_link;
	if (af == AF_CCITT)
		goto do_ccitt;
	if (af == 0)
		goto do_sa;
	if (hpp == NULL)
		hpp = &hp;
	*hpp = NULL;
	if (((val = inet_addr(s)) != -1) &&
	    (which != RTA_DST || forcenet == 0)) {
		su->sin.sin_addr.s_addr = val;
		if (inet_lnaof(su->sin.sin_addr) != INADDR_ANY)
			return (1);
		else {
			val = ntohl(val);
		out:	if (which == RTA_DST)
				inet_makenetandmask(val, &su->sin);
			return (0);
		}
	}
	val = inet_network(s);
	if (val != -1) {
		goto out;
	}
	np = getnetbyname(s);
	if (np) {
		val = np->n_net;
		goto out;
	}
	hp = gethostbyname(s);
	if (hp) {
		*hpp = hp;
		su->sin.sin_family = hp->h_addrtype;
		bcopy(hp->h_addr, (char *)&su->sin.sin_addr, hp->h_length);
		return (1);
	}
	(void) fprintf(stderr, "%s: bad value\n", s);
	exit(1);
do_xns:
	if (which == RTA_DST) {
		extern short ns_bh[3];
		struct sockaddr_ns *sms = &(so_mask.sns);
		bzero((char *)sms, sizeof(*sms));
		sms->sns_family = 0;
		sms->sns_len = 6;
		sms->sns_addr.x_net = *(union ns_net *)ns_bh;
		rtm_addrs |= RTA_NETMASK;
	}
	su->sns.sns_addr = ns_addr(s);
	return (!ns_nullhost(su->sns.sns_addr));
do_osi:
	su->siso.siso_addr = *iso_addr(s);
	if (which == RTA_NETMASK || which == RTA_GENMASK) {
		register char *cp = (char *)TSEL(&su->siso);
		su->siso.siso_nlen = 0;
		do {--cp ;} while ((cp > (char *)su) && (*cp == 0));
		su->siso.siso_len = 1 + cp - (char *)su;
	}
	return (1);
do_ccitt:
	ccitt_addr(s, &su->sx25);
	return (1);
do_link:
	link_addr(s, &su->sdl);
	return (1);
do_sa:
	su->sa.sa_len = sizeof(*su);
	sockaddr(s, &su->sa);
	return (1);
}

short ns_nullh[] = {0,0,0};
short ns_bh[] = {-1,-1,-1};

char *
ns_print(sns)
	struct sockaddr_ns *sns;
{
	struct ns_addr work;
	union { union ns_net net_e; u_long long_e; } net;
	u_short port;
	static char mybuf[50], cport[10], chost[25];
	char *host = "";
	register char *p;
	register u_char *q;

	work = sns->sns_addr;
	port = ntohs(work.x_port);
	work.x_port = 0;
	net.net_e  = work.x_net;
	if (ns_nullhost(work) && net.long_e == 0) {
		if (!port)
			return ("*.*");
		(void) sprintf(mybuf, "*.%XH", port);
		return (mybuf);
	}

	if (bcmp((char *)ns_bh, (char *)work.x_host.c_host, 6) == 0) 
		host = "any";
	else if (bcmp((char *)ns_nullh, (char *)work.x_host.c_host, 6) == 0)
		host = "*";
	else {
		q = work.x_host.c_host;
		(void) sprintf(chost, "%02X%02X%02X%02X%02X%02XH",
			q[0], q[1], q[2], q[3], q[4], q[5]);
		for (p = chost; *p == '0' && p < chost + 12; p++)
			/* void */;
		host = p;
	}
	if (port)
		(void) sprintf(cport, ".%XH", htons(port));
	else
		*cport = 0;

	(void) sprintf(mybuf,"%XH.%s%s", ntohl(net.long_e), host, cport);
	return (mybuf);
}

void
monitor()
{
	int n;
	char msg[2048];

	verbose = 1;
	for(;;) {
		n = read(s, msg, 2048);
		(void) printf("got message of size %d\n", n);
		print_rtmsg((struct rt_msghdr *)msg);
	}
}

struct {
	struct	rt_msghdr m_rtm;
	char	m_space[512];
} m_rtmsg;

int
rtmsg(cmd, flags)
	int cmd, flags;
{
	static int seq;
	int rlen;
	register char *cp = m_rtmsg.m_space;
	register int l;

#define NEXTADDR(w, u) \
	if (rtm_addrs & (w)) {\
	    l = ROUNDUP(u.sa.sa_len); bcopy((char *)&(u), cp, l); cp += l;\
	    if (verbose) sodump(&(u),"u");\
	}

	errno = 0;
	bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
	if (cmd == 'a')
		cmd = RTM_ADD;
	else if (cmd == 'c')
		cmd = RTM_CHANGE;
	else if (cmd == 'g')
		cmd = RTM_GET;
	else
		cmd = RTM_DELETE;
#define rtm m_rtmsg.m_rtm
	rtm.rtm_type = cmd;
	rtm.rtm_flags = flags;
	rtm.rtm_version = RTM_VERSION;
	rtm.rtm_seq = ++seq;
	rtm.rtm_addrs = rtm_addrs;
	rtm.rtm_rmx = rt_metrics;
	rtm.rtm_inits = rtm_inits;

	if (rtm_addrs & RTA_NETMASK)
		mask_addr();
	NEXTADDR(RTA_DST, so_dst);
	NEXTADDR(RTA_GATEWAY, so_gate);
	NEXTADDR(RTA_NETMASK, so_mask);
	NEXTADDR(RTA_GENMASK, so_genmask);
	NEXTADDR(RTA_IFP, so_ifp);
	NEXTADDR(RTA_IFA, so_ifa);
	rtm.rtm_msglen = l = cp - (char *)&m_rtmsg;
	if (verbose)
		print_rtmsg(&rtm, l);
	if (debugonly)
		return 0;
	if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
		perror("writing to routing socket");
		return (-1);
	}
	if (cmd == RTM_GET) {
		do {
			l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
		} while (l > 0 && (rtm.rtm_seq != seq || rtm.rtm_pid != pid));
		if (l < 0)
			(void) fprintf(stderr,
			    "route: read from routing socket: %s\n",
			    strerror(errno));
		else
			print_getmsg(&rtm, l);
	}
#undef rtm
	return (0);
}

mask_addr() {
	register char *cp1, *cp2;
	int olen;

	if ((rtm_addrs & RTA_DST) == 0)
		return;
	switch(so_dst.sa.sa_family) {
	case AF_NS: case AF_INET: case 0:
		return;
	case AF_ISO:
		olen = MIN(so_dst.siso.siso_nlen, so_mask.sa.sa_len - 6);
	}
	cp1 = so_mask.sa.sa_len + 1 + (char *)&so_dst;
	cp2 = so_dst.sa.sa_len + 1 + (char *)&so_dst;
	while (cp2 > cp1)
		*--cp2 = 0;
	cp2 = so_mask.sa.sa_len + 1 + (char *)&so_mask;
	while (cp1 > so_dst.sa.sa_data)
		*--cp1 &= *--cp2;
	switch(so_dst.sa.sa_family) {
	case AF_ISO:
		so_dst.siso.siso_nlen = olen;
	}
}

char *msgtypes[] = {
	"",
	"RTM_ADD: Add Route",
	"RTM_DELETE: Delete Route",
	"RTM_CHANGE: Change Metrics or flags",
	"RTM_GET: Report Metrics",
	"RTM_LOSING: Kernel Suspects Partitioning",
	"RTM_REDIRECT: Told to use different route",
	"RTM_MISS: Lookup failed on this address",
	"RTM_LOCK: fix specified metrics",
	"RTM_OLDADD: caused by SIOCADDRT",
	"RTM_OLDDEL: caused by SIOCDELRT",
	0,
};

char metricnames[] =
"\010rttvar\7rtt\6ssthresh\5sendpipe\4recvpipe\3expire\2hopcount\1mtu";
char routeflags[] = 
"\1UP\2GATEWAY\3HOST\4REJECT\5DYNAMIC\6MODIFIED\7DONE\010MASK_PRESENT\011CLONING\012XRESOLVE\013LLINFO\017PROTO2\020PROTO1";


void
print_rtmsg(rtm, msglen)
	register struct rt_msghdr *rtm;
	int msglen;
{
	if (verbose == 0)
		return;
	if (rtm->rtm_version != RTM_VERSION) {
		(void) printf("routing message version %d not understood\n",
		    rtm->rtm_version);
		return;
	}
	(void) printf("%s\npid: %d, len %d, seq %d, errno %d, flags:",
		msgtypes[rtm->rtm_type], rtm->rtm_pid, rtm->rtm_msglen,
		rtm->rtm_seq, rtm->rtm_errno); 
	bprintf(stdout, rtm->rtm_flags, routeflags);
	pmsg_common(rtm);
}

void
print_getmsg(rtm, msglen)
	register struct rt_msghdr *rtm;
	int msglen;
{
	if (rtm->rtm_version != RTM_VERSION) {
		(void)printf("routing message version %d not understood\n",
		    rtm->rtm_version);
		return;
	}
	if (rtm->rtm_msglen > msglen) {
		(void)printf("get length mismatch, in packet %d, returned %d\n",
		    rtm->rtm_msglen, msglen);
	}
	(void) printf("RTM_GET: errno %d, flags:", rtm->rtm_errno); 
	bprintf(stdout, rtm->rtm_flags, routeflags);
	(void) printf("\nmetric values:\n  ");
#define metric(f, e)\
    printf("%s: %d%s", __STRING(f), rtm->rtm_rmx.__CONCAT(rmx_,f), e)
	metric(recvpipe, ", ");
	metric(sendpipe, ", ");
	metric(ssthresh, ", ");
	metric(rtt, "\n  ");
	metric(rttvar, ", ");
	metric(hopcount, ", ");
	metric(mtu, ", ");
	metric(expire, "\n");
#undef metric
	pmsg_common(rtm);
}

void
pmsg_common(rtm)
	register struct rt_msghdr *rtm;
{
	char *cp;
	register struct sockaddr *sa;
	int i;

	(void) printf("\nlocks: ");
	bprintf(stdout, rtm->rtm_rmx.rmx_locks, metricnames);
	(void) printf(" inits: ");
	bprintf(stdout, rtm->rtm_inits, metricnames);
	(void) printf("\nsockaddrs: ");
	bprintf(stdout, rtm->rtm_addrs,
	    "\1DST\2GATEWAY\3NETMASK\4GENMASK\5IFP\6IFA\7AUTHOR");
	(void) putchar('\n');
	cp = ((char *)(rtm + 1));
	if (rtm->rtm_addrs)
		for (i = 1; i; i <<= 1)
			if (i & rtm->rtm_addrs) {
				sa = (struct sockaddr *)cp;
				(void) printf(" %s", routename(sa));
				ADVANCE(cp, sa);
			}
	(void) putchar('\n');
	(void) fflush(stdout);
}

void
bprintf(fp, b, s)
	register FILE *fp;
	register int b;
	register u_char *s;
{
	register int i;
	int gotsome = 0;

	if (b == 0)
		return;
	while (i = *s++) {
		if (b & (1 << (i-1))) {
			if (gotsome == 0)
				i = '<';
			else
				i = ',';
			(void) putc(i, fp);
			gotsome = 1;
			for (; (i = *s) > 32; s++)
				(void) putc(i, fp);
		} else
			while (*s > 32)
				s++;
	}
	if (gotsome)
		(void) putc('>', fp);
}

int
keyword(cp)
	char *cp;
{
	register struct keytab *kt = keywords;

	while (kt->kt_cp && strcmp(kt->kt_cp, cp))
		kt++;
	return kt->kt_i;
}

void
sodump(su, which)
	register sup su;
	char *which;
{
	switch (su->sa.sa_family) {
	case AF_LINK:
		(void) printf("%s: link %s; ",
		    which, link_ntoa(&su->sdl));
		break;
	case AF_ISO:
		(void) printf("%s: iso %s; ",
		    which, iso_ntoa(&su->siso.siso_addr));
		break;
	case AF_INET:
		(void) printf("%s: inet %s; ",
		    which, inet_ntoa(su->sin.sin_addr));
		break;
	case AF_NS:
		(void) printf("%s: xns %s; ",
		    which, ns_ntoa(su->sns.sns_addr));
		break;
	}
	(void) fflush(stdout);
}
/* States*/
#define VIRGIN	0
#define GOTONE	1
#define GOTTWO	2
/* Inputs */
#define	DIGIT	(4*0)
#define	END	(4*1)
#define DELIM	(4*2)

void
sockaddr(addr, sa)
register char *addr;
register struct sockaddr *sa;
{
	register char *cp = (char *)sa;
	int size = sa->sa_len;
	char *cplim = cp + size;
	register int byte = 0, state = VIRGIN, new;

	bzero(cp, size);
	do {
		if ((*addr >= '0') && (*addr <= '9')) {
			new = *addr - '0';
		} else if ((*addr >= 'a') && (*addr <= 'f')) {
			new = *addr - 'a' + 10;
		} else if ((*addr >= 'A') && (*addr <= 'F')) {
			new = *addr - 'A' + 10;
		} else if (*addr == 0) 
			state |= END;
		else
			state |= DELIM;
		addr++;
		switch (state /* | INPUT */) {
		case GOTTWO | DIGIT:
			*cp++ = byte; /*FALLTHROUGH*/
		case VIRGIN | DIGIT:
			state = GOTONE; byte = new; continue;
		case GOTONE | DIGIT:
			state = GOTTWO; byte = new + (byte << 4); continue;
		default: /* | DELIM */
			state = VIRGIN; *cp++ = byte; byte = 0; continue;
		case GOTONE | END:
		case GOTTWO | END:
			*cp++ = byte; /* FALLTHROUGH */
		case VIRGIN | END:
			break;
		}
		break;
	} while (cp < cplim); 
	sa->sa_len = cp - (char *)sa;
}