route.c

早期freebsd实现

	int mib[6];
	char *buf, *lim, *next;
	register struct rt_msghdr *rtm;

	mib[0] = CTL_NET;
	mib[1] = PF_ROUTE;
	mib[2] = 0;		/* protocol */
	mib[3] = 0;		/* wildcard address family */
	mib[4] = NET_RT_IFLIST;
	mib[5] = 0;		/* no flags */
	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
		quit("route-sysctl-estimate");
	if ((buf = malloc(needed)) == NULL)
		quit("malloc");
	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
		quit("actual retrieval of interface table");
	lim = buf + needed;
	for (next = buf; next < lim; next += rtm->rtm_msglen) {
		rtm = (struct rt_msghdr *)next;
		print_rtmsg(rtm, rtm->rtm_msglen);
	}
}

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

	verbose = 1;
	if (debugonly) {
		interfaces();
		exit(0);
	}
	for(;;) {
		n = read(s, msg, 2048);
		(void) printf("got message of size %d\n", n);
		print_rtmsg((struct rt_msghdr *)msg, n);
	}
}

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;
		if (so_ifp.sa.sa_family == 0) {
			so_ifp.sa.sa_family == AF_LINK;
			so_ifp.sa.sa_len == sizeof(struct sockaddr_dl);
			rtm_addrs |= RTA_IFP;
		}
	} 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);
}

void
mask_addr()
{
	int olen = so_mask.sa.sa_len;
	register char *cp1 = olen + (char *)&so_mask, *cp2;

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

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",
	"RTM_RESOLVE: Route created by cloning",
	"RTM_NEWADDR: address being added to iface",
	"RTM_DELADDR: address being removed from iface",
	"RTM_IFINFO: iface status change",
	0,
};

char metricnames[] =
"\011pksent\010rttvar\7rtt\6ssthresh\5sendpipe\4recvpipe\3expire\2hopcount\1mtu";
char routeflags[] =
"\1UP\2GATEWAY\3HOST\4REJECT\5DYNAMIC\6MODIFIED\7DONE\010MASK_PRESENT\011CLONING\012XRESOLVE\013LLINFO\014STATIC\017PROTO2\020PROTO1";
char ifnetflags[] =
"\1UP\2BROADCAST\3DEBUG\4LOOPBACK\5PTP\6NOTRAILERS\7RUNNING\010NOARP\011PPROMISC\012ALLMULTI\013OACTIVE\014SIMPLEX\015LINK0\016LINK1\017LINK2\020MULTICAST";
char addrnames[] =
"\1DST\2GATEWAY\3NETMASK\4GENMASK\5IFP\6IFA\7AUTHOR\010BRD";

void
print_rtmsg(rtm, msglen)
	register struct rt_msghdr *rtm;
	int msglen;
{
	struct if_msghdr *ifm;
	struct ifa_msghdr *ifam;

	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: len %d, ", msgtypes[rtm->rtm_type], rtm->rtm_msglen);
	switch (rtm->rtm_type) {
	case RTM_IFINFO:
		ifm = (struct if_msghdr *)rtm;
		(void) printf("if# %d, flags:", ifm->ifm_index);
		bprintf(stdout, ifm->ifm_flags, ifnetflags);
		pmsg_addrs((char *)(ifm + 1), ifm->ifm_addrs);
		break;
	case RTM_NEWADDR:
	case RTM_DELADDR:
		ifam = (struct ifa_msghdr *)rtm;
		(void) printf("metric %d, flags:", ifam->ifam_metric);
		bprintf(stdout, ifam->ifam_flags, routeflags);
		pmsg_addrs((char *)(ifam + 1), ifam->ifam_addrs);
		break;
	default:
		(void) printf("pid: %d, seq %d, errno %d, flags:",
			rtm->rtm_pid, 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;
{
	struct sockaddr *dst = NULL, *gate = NULL, *mask = NULL;
	struct sockaddr_dl *ifp = NULL;
	register struct sockaddr *sa;
	register char *cp;
	register int i;

	(void) printf("   route to: %s\n", routename(&so_dst));
	if (rtm->rtm_version != RTM_VERSION) {
		(void)fprintf(stderr,
		    "routing message version %d not understood\n",
		    rtm->rtm_version);
		return;
	}
	if (rtm->rtm_msglen > msglen) {
		(void)fprintf(stderr,
		    "message length mismatch, in packet %d, returned %d\n",
		    rtm->rtm_msglen, msglen);
	}
	if (rtm->rtm_errno)  {
		(void) fprintf(stderr, "RTM_GET: %s (errno %d)\n",
		    strerror(rtm->rtm_errno), rtm->rtm_errno);
		return;
	}
	cp = ((char *)(rtm + 1));
	if (rtm->rtm_addrs)
		for (i = 1; i; i <<= 1)
			if (i & rtm->rtm_addrs) {
				sa = (struct sockaddr *)cp;
				switch (i) {
				case RTA_DST:
					dst = sa;
					break;
				case RTA_GATEWAY:
					gate = sa;
					break;
				case RTA_NETMASK:
					mask = sa;
					break;
				case RTA_IFP:
					if (sa->sa_family == AF_LINK &&
					   ((struct sockaddr_dl *)sa)->sdl_nlen)
						ifp = (struct sockaddr_dl *)sa;
					break;
				}
				ADVANCE(cp, sa);
			}
	if (dst && mask)
		mask->sa_family = dst->sa_family;	/* XXX */
	if (dst)
		(void)printf("destination: %s\n", routename(dst));
	if (mask) {
		int savenflag = nflag;

		nflag = 1;
		(void)printf("       mask: %s\n", routename(mask));
		nflag = savenflag;
	}
	if (gate && rtm->rtm_flags & RTF_GATEWAY)
		(void)printf("    gateway: %s\n", routename(gate));
	if (ifp)
		(void)printf("  interface: %.*s\n",
		    ifp->sdl_nlen, ifp->sdl_data);
	(void)printf("      flags: ");
	bprintf(stdout, rtm->rtm_flags, routeflags);

#define lock(f)	((rtm->rtm_rmx.rmx_locks & __CONCAT(RTV_,f)) ? 'L' : ' ')
#define msec(u)	(((u) + 500) / 1000)		/* usec to msec */

	(void) printf("\n%s\n", "\
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire");
	printf("%8d%c ", rtm->rtm_rmx.rmx_recvpipe, lock(RPIPE));
	printf("%8d%c ", rtm->rtm_rmx.rmx_sendpipe, lock(SPIPE));
	printf("%8d%c ", rtm->rtm_rmx.rmx_ssthresh, lock(SSTHRESH));
	printf("%8d%c ", msec(rtm->rtm_rmx.rmx_rtt), lock(RTT));
	printf("%8d%c ", msec(rtm->rtm_rmx.rmx_rttvar), lock(RTTVAR));
	printf("%8d%c ", rtm->rtm_rmx.rmx_hopcount, lock(HOPCOUNT));
	printf("%8d%c ", rtm->rtm_rmx.rmx_mtu, lock(MTU));
	if (rtm->rtm_rmx.rmx_expire)
		rtm->rtm_rmx.rmx_expire -= time(0);
	printf("%8d%c\n", rtm->rtm_rmx.rmx_expire, lock(EXPIRE));
#undef lock
#undef msec
#define	RTA_IGN	(RTA_DST|RTA_GATEWAY|RTA_NETMASK|RTA_IFP|RTA_IFA|RTA_BRD)
	if (verbose)
		pmsg_common(rtm);
	else if (rtm->rtm_addrs &~ RTA_IGN) {
		(void) printf("sockaddrs: ");
		bprintf(stdout, rtm->rtm_addrs, addrnames);
		putchar('\n');
	}
#undef	RTA_IGN
}

void
pmsg_common(rtm)
	register struct rt_msghdr *rtm;
{
	(void) printf("\nlocks: ");
	bprintf(stdout, rtm->rtm_rmx.rmx_locks, metricnames);
	(void) printf(" inits: ");
	bprintf(stdout, rtm->rtm_inits, metricnames);
	pmsg_addrs(((char *)(rtm + 1)), rtm->rtm_addrs);
}

void
pmsg_addrs(cp, addrs)
	char	*cp;
	int	addrs;
{
	register struct sockaddr *sa;
	int i;

	if (addrs == 0)
		return;
	(void) printf("\nsockaddrs: ");
	bprintf(stdout, addrs, addrnames);
	(void) putchar('\n');
	for (i = 1; i; i <<= 1)
		if (i & 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);
	cp++;
	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;
}