Restore netstat -M functionality for most statistics on core dumps. In

general, when support was added to netstat for fetching data using sysctl,
no provision was left for fetching equivalent data from a core dump, and
in fact, netstat would _always_ fetch data from the live kernel using
sysctl even when -M was specified resulting in the user believing they
were getting data from coredumps when they actually weren't.  Some specific
changes:
- Add a global 'live' variable that is true if netstat is running against
  the live kernel and false if -M has been specified.
- Stop abusing the sysctl flag in the protocol tables to hold the protocol
  number.  Instead, the protocol is now its own field in the tables, and
  it is passed as a separate parameter to the PCB and stat routines rather
  than overloading the KVM offset parameter.
- Don't run PCB or stats functions who don't have a namelist offset if we
  are being run against a crash dump (!live).
- For the inet and unix PCB routines, we generate the same buffer from KVM
  that the sysctl usually generates complete with the header and trailer.
- Don't run bpf stats for !live (before it would just silently always run
  live).
- kread() no longer trashes memory when opening the buffer if there is an
  error on open and the passed in buffer is smaller than _POSIX2_LINE_MAX.
- The multicast routing code doesn't fallback to kvm on live kernels if
  the sysctl fails.  Keeping this made the code rather hairy, and netstat
  is already tied to the kernel ABI anyway (even when using sysctl's since
  things like xinpcb contain an inpcb) so any kernels this is run against
  that have the multicast routing stuff should have the sysctls.
- Don't try to dig around in the kernel linker in the netgraph PCB routine
  for core dumps.

Other notes:
- sctp's PCB routine only works on live kernels, it looked rather
  complicated to generate all the same stuff via KVM.  Someone can always
  add it later if desired though.
- Fix the ipsec removal bug where N_xxx for IPSEC stats weren't renumbered.
- Use sysctlbyname() everywhere rather than hardcoded mib values.

MFC after:	1 week
Approved by:	re (rwatson)

1 files changed, 306 insertions, 97 deletions

diff --git a/usr.bin/netstat/inet.c b/usr.bin/netstat/inet.c
index 1be7b87..eee2fef 100644
--- a/usr.bin/netstat/inet.c
+++ b/usr.bin/netstat/inet.c
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/queue.h>
+#include <sys/domain.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
@@ -90,6 +91,208 @@ void	inetprint (struct in_addr *, int, const char *, int);
 static int udp_done, tcp_done;
 #endif /* INET6 */
 
+static int
+pcblist_sysctl(int proto, char **bufp, int istcp)
+{
+	const char *mibvar;
+	char *buf;
+	size_t len;
+
+	switch (proto) {
+	case IPPROTO_TCP:
+		mibvar = "net.inet.tcp.pcblist";
+		break;
+	case IPPROTO_UDP:
+		mibvar = "net.inet.udp.pcblist";
+		break;
+	case IPPROTO_DIVERT:
+		mibvar = "net.inet.divert.pcblist";
+		break;
+	default:
+		mibvar = "net.inet.raw.pcblist";
+		break;
+	}
+
+	len = 0;
+	if (sysctlbyname(mibvar, 0, &len, 0, 0) < 0) {
+		if (errno != ENOENT)
+			warn("sysctl: %s", mibvar);
+		return (0);
+	}
+	if ((buf = malloc(len)) == 0) {
+		warnx("malloc %lu bytes", (u_long)len);
+		return (0);
+	}
+	if (sysctlbyname(mibvar, buf, &len, 0, 0) < 0) {
+		warn("sysctl: %s", mibvar);
+		free(buf);
+		return (0);
+	}
+	*bufp = buf;
+	return (1);
+}
+
+/*
+ * Copied directly from uipc_socket2.c.  We leave out some fields that are in
+ * nested structures that aren't used to avoid extra work.
+ */
+static void
+sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
+{
+	xsb->sb_cc = sb->sb_cc;
+	xsb->sb_hiwat = sb->sb_hiwat;
+	xsb->sb_mbcnt = sb->sb_mbcnt;
+	xsb->sb_mbmax = sb->sb_mbmax;
+	xsb->sb_lowat = sb->sb_lowat;
+	xsb->sb_flags = sb->sb_flags;
+	xsb->sb_timeo = sb->sb_timeo;
+}
+
+int
+sotoxsocket(struct socket *so, struct xsocket *xso)
+{
+	struct protosw proto;
+	struct domain domain;
+
+	bzero(xso, sizeof *xso);
+	xso->xso_len = sizeof *xso;
+	xso->xso_so = so;
+	xso->so_type = so->so_type;
+	xso->so_options = so->so_options;
+	xso->so_linger = so->so_linger;
+	xso->so_state = so->so_state;
+	xso->so_pcb = so->so_pcb;
+	if (kread((uintptr_t)so->so_proto, &proto, sizeof(proto)) != 0)
+		return (-1);
+	xso->xso_protocol = proto.pr_protocol;
+	if (kread((uintptr_t)proto.pr_domain, &domain, sizeof(domain)) != 0)
+		return (-1);
+	xso->xso_family = domain.dom_family;
+	xso->so_qlen = so->so_qlen;
+	xso->so_incqlen = so->so_incqlen;
+	xso->so_qlimit = so->so_qlimit;
+	xso->so_timeo = so->so_timeo;
+	xso->so_error = so->so_error;
+	xso->so_oobmark = so->so_oobmark;
+	sbtoxsockbuf(&so->so_snd, &xso->so_snd);
+	sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
+	return (0);
+}
+
+static int
+pcblist_kvm(u_long off, char **bufp, int istcp)
+{
+	struct inpcbinfo pcbinfo;
+	struct inpcbhead listhead;
+	struct inpcb *inp;
+	struct xinpcb xi;
+	struct xinpgen xig;
+	struct xtcpcb xt;
+	struct socket so;
+	struct xsocket *xso;
+	char *buf, *p;
+	size_t len;
+
+	if (off == 0)
+		return (0);
+	kread(off, &pcbinfo, sizeof(pcbinfo));
+	if (istcp)
+		len = 2 * sizeof(xig) +
+		    (pcbinfo.ipi_count + pcbinfo.ipi_count / 8) *
+		    sizeof(struct xtcpcb);
+	else
+		len = 2 * sizeof(xig) +
+		    (pcbinfo.ipi_count + pcbinfo.ipi_count / 8) *
+		    sizeof(struct xinpcb);
+	if ((buf = malloc(len)) == 0) {
+		warnx("malloc %lu bytes", (u_long)len);
+		return (0);
+	}
+	p = buf;
+
+#define COPYOUT(obj, size) do {						\
+	if (len < (size)) {						\
+		warnx("buffer size exceeded");				\
+		goto fail;						\
+	}								\
+	bcopy((obj), p, (size));					\
+	len -= (size);							\
+	p += (size);							\
+} while (0)
+
+#define KREAD(off, buf, len) do {					\
+	if (kread((uintptr_t)(off), (buf), (len)) != 0)			\
+		goto fail;						\
+} while (0)
+
+	/* Write out header. */
+	xig.xig_len = sizeof xig;
+	xig.xig_count = pcbinfo.ipi_count;
+	xig.xig_gen = pcbinfo.ipi_gencnt;
+	xig.xig_sogen = 0;
+	COPYOUT(&xig, sizeof xig);
+
+	/* Walk the PCB list. */
+	xt.xt_len = sizeof xt;
+	xi.xi_len = sizeof xi;
+	if (istcp)
+		xso = &xt.xt_socket;
+	else
+		xso = &xi.xi_socket;
+	KREAD(pcbinfo.ipi_listhead, &listhead, sizeof(listhead));
+	LIST_FOREACH(inp, &listhead, inp_list) {
+		if (istcp) {
+			KREAD(inp, &xt.xt_inp, sizeof(*inp));
+			inp = &xt.xt_inp;
+		} else {
+			KREAD(inp, &xi.xi_inp, sizeof(*inp));
+			inp = &xi.xi_inp;
+		}
+
+		if (inp->inp_gencnt > pcbinfo.ipi_gencnt)
+			continue;
+
+		if (istcp) {
+			if (inp->inp_ppcb == NULL)
+				bzero(&xt.xt_tp, sizeof xt.xt_tp);
+			else if (inp->inp_vflag & INP_TIMEWAIT) {
+				bzero(&xt.xt_tp, sizeof xt.xt_tp);
+				xt.xt_tp.t_state = TCPS_TIME_WAIT;
+			} else
+				KREAD(inp->inp_ppcb, &xt.xt_tp,
+				    sizeof xt.xt_tp);
+		}
+		if (inp->inp_socket) {
+			KREAD(inp->inp_socket, &so, sizeof(so));
+			if (sotoxsocket(&so, xso) != 0)
+				goto fail;
+		} else {
+			bzero(xso, sizeof(*xso));
+			if (istcp)
+				xso->xso_protocol = IPPROTO_TCP;
+		}
+		if (istcp)
+			COPYOUT(&xt, sizeof xt);
+		else
+			COPYOUT(&xi, sizeof xi);		
+	}
+
+	/* Reread the pcbinfo and write out the footer. */
+	kread(off, &pcbinfo, sizeof(pcbinfo));
+	xig.xig_count = pcbinfo.ipi_count;
+	xig.xig_gen = pcbinfo.ipi_gencnt;
+	COPYOUT(&xig, sizeof xig);
+	
+	*bufp = buf;
+	return (1);
+
+fail:
+	free(buf);
+	return (0);
+#undef COPYOUT
+#undef KREAD
+}
+
 /*
  * Print a summary of connections related to an Internet
  * protocol.  For TCP, also give state of connection.
@@ -97,18 +300,16 @@ static int udp_done, tcp_done;
  * -a (all) flag is specified.
  */
 void
-protopr(u_long proto,		/* for sysctl version we pass proto # */
-	const char *name, int af1)
+protopr(u_long off, const char *name, int af1, int proto)
 {
 	int istcp;
 	static int first = 1;
 	char *buf;
-	const char *mibvar, *vchar;
+	const char *vchar;
 	struct tcpcb *tp = NULL;
 	struct inpcb *inp;
 	struct xinpgen *xig, *oxig;
 	struct xsocket *so;
-	size_t len;
 
 	istcp = 0;
 	switch (proto) {
@@ -120,7 +321,6 @@ protopr(u_long proto,		/* for sysctl version we pass proto # */
 			tcp_done = 1;
 #endif
 		istcp = 1;
-		mibvar = "net.inet.tcp.pcblist";
 		break;
 	case IPPROTO_UDP:
 #ifdef INET6
@@ -129,29 +329,14 @@ protopr(u_long proto,		/* for sysctl version we pass proto # */
 		else
 			udp_done = 1;
 #endif
-		mibvar = "net.inet.udp.pcblist";
-		break;
-	case IPPROTO_DIVERT:
-		mibvar = "net.inet.divert.pcblist";
-		break;
-	default:
-		mibvar = "net.inet.raw.pcblist";
 		break;
 	}
-	len = 0;
-	if (sysctlbyname(mibvar, 0, &len, 0, 0) < 0) {
-		if (errno != ENOENT)
-			warn("sysctl: %s", mibvar);
-		return;
-	}
-	if ((buf = malloc(len)) == 0) {
-		warnx("malloc %lu bytes", (u_long)len);
-		return;
-	}
-	if (sysctlbyname(mibvar, buf, &len, 0, 0) < 0) {
-		warn("sysctl: %s", mibvar);
-		free(buf);
-		return;
+	if (live) {
+		if (!pcblist_sysctl(proto, &buf, istcp))
+			return;
+	} else {
+		if (!pcblist_kvm(off, &buf, istcp))
+			return;
 	}
 
 	oxig = xig = (struct xinpgen *)buf;
@@ -168,7 +353,7 @@ protopr(u_long proto,		/* for sysctl version we pass proto # */
 		}
 
 		/* Ignore sockets for protocols other than the desired one. */
-		if (so->xso_protocol != (int)proto)
+		if (so->xso_protocol != proto)
 			continue;
 
 		/* Ignore PCBs which were freed during copyout. */
@@ -347,18 +532,10 @@ protopr(u_long proto,		/* for sysctl version we pass proto # */
  * Dump TCP statistics structure.
  */
 void
-tcp_stats(u_long off __unused, const char *name, int af1 __unused)
+tcp_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct tcpstat tcpstat, zerostat;
 	size_t len = sizeof tcpstat;
-	
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.tcp.stats", &tcpstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		warn("sysctl: net.inet.tcp.stats");
-		return;
-	}
 
 #ifdef INET6
 	if (tcp_done != 0)
@@ -367,6 +544,17 @@ tcp_stats(u_long off __unused, const char *name, int af1 __unused)
 		tcp_done = 1;
 #endif
 
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.tcp.stats", &tcpstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			warn("sysctl: net.inet.tcp.stats");
+			return;
+		}
+	} else
+		kread(off, &tcpstat, len);
+
 	printf ("%s:\n", name);
 
 #define	p(f, m) if (tcpstat.f || sflag <= 1) \
@@ -480,20 +668,12 @@ tcp_stats(u_long off __unused, const char *name, int af1 __unused)
  * Dump UDP statistics structure.
  */
 void
-udp_stats(u_long off __unused, const char *name, int af1 __unused)
+udp_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct udpstat udpstat, zerostat;
 	size_t len = sizeof udpstat;
 	u_long delivered;
 
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.udp.stats", &udpstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		warn("sysctl: net.inet.udp.stats");
-		return;
-	}
-
 #ifdef INET6
 	if (udp_done != 0)
 		return;
@@ -501,6 +681,17 @@ udp_stats(u_long off __unused, const char *name, int af1 __unused)
 		udp_done = 1;
 #endif
 
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.udp.stats", &udpstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			warn("sysctl: net.inet.udp.stats");
+			return;
+		}
+	} else
+		kread(off, &udpstat, len);
+
 	printf("%s:\n", name);
 #define	p(f, m) if (udpstat.f || sflag <= 1) \
     printf(m, udpstat.f, plural(udpstat.f))
@@ -537,18 +728,24 @@ udp_stats(u_long off __unused, const char *name, int af1 __unused)
  * Dump CARP statistics structure.
  */
 void
-carp_stats(u_long off __unused, const char *name, int af1 __unused)
+carp_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct carpstats carpstat, zerostat;
 	size_t len = sizeof(struct carpstats);
 
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.carp.stats", &carpstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		if (errno != ENOENT)
-			warn("sysctl: net.inet.carp.stats");
-		return;
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.carp.stats", &carpstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			if (errno != ENOENT)
+				warn("sysctl: net.inet.carp.stats");
+			return;
+		}
+	} else {
+		if (off == 0)
+			return;
+		kread(off, &carpstat, len);
 	}
 
 	printf("%s:\n", name);
@@ -582,18 +779,21 @@ carp_stats(u_long off __unused, const char *name, int af1 __unused)
  * Dump IP statistics structure.
  */
 void
-ip_stats(u_long off __unused, const char *name, int af1 __unused)
+ip_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct ipstat ipstat, zerostat;
 	size_t len = sizeof ipstat;
 
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.ip.stats", &ipstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		warn("sysctl: net.inet.ip.stats");
-		return;
-	}
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.ip.stats", &ipstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			warn("sysctl: net.inet.ip.stats");
+			return;
+		}
+	} else
+		kread(off, &ipstat, len);
 
 	printf("%s:\n", name);
 
@@ -687,26 +887,23 @@ static	const char *icmpnames[ICMP_MAXTYPE + 1] = {
  * Dump ICMP statistics.
  */
 void
-icmp_stats(u_long off __unused, const char *name, int af1 __unused)
+icmp_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct icmpstat icmpstat, zerostat;
 	int i, first;
-	int mib[4];		/* CTL_NET + PF_INET + IPPROTO_ICMP + req */
 	size_t len;
 
-	mib[0] = CTL_NET;
-	mib[1] = PF_INET;
-	mib[2] = IPPROTO_ICMP;
-	mib[3] = ICMPCTL_STATS;
-
 	len = sizeof icmpstat;
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctl(mib, 4, &icmpstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		warn("sysctl: net.inet.icmp.stats");
-		return;
-	}
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.icmp.stats", &icmpstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			warn("sysctl: net.inet.icmp.stats");
+			return;
+		}
+	} else
+		kread(off, &icmpstat, len);
 
 	printf("%s:\n", name);
 
@@ -758,30 +955,35 @@ icmp_stats(u_long off __unused, const char *name, int af1 __unused)
 #undef p
 #undef p1a
 #undef p2
-	mib[3] = ICMPCTL_MASKREPL;
-	len = sizeof i;
-	if (sysctl(mib, 4, &i, &len, (void *)0, 0) < 0)
-		return;
-	printf("\tICMP address mask responses are %sabled\n", 
-	       i ? "en" : "dis");
+	if (live) {
+		len = sizeof i;
+		if (sysctlbyname("net.inet.icmp.maskrepl", &i, &len, NULL, 0) <
+		    0)
+			return;
+		printf("\tICMP address mask responses are %sabled\n", 
+		    i ? "en" : "dis");
+	}
 }
 
 /*
  * Dump IGMP statistics structure.
  */
 void
-igmp_stats(u_long off __unused, const char *name, int af1 __unused)
+igmp_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
 {
 	struct igmpstat igmpstat, zerostat;
 	size_t len = sizeof igmpstat;
 
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.igmp.stats", &igmpstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		warn("sysctl: net.inet.igmp.stats");
-		return;
-	}
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.igmp.stats", &igmpstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			warn("sysctl: net.inet.igmp.stats");
+			return;
+		}
+	} else
+		kread(off, &igmpstat, len);
 
 	printf("%s:\n", name);
 
@@ -806,18 +1008,25 @@ igmp_stats(u_long off __unused, const char *name, int af1 __unused)
  * Dump PIM statistics structure.
  */
 void
-pim_stats(u_long off __unused, const char *name, int af1 __unused)
+pim_stats(u_long off __unused, const char *name, int af1 __unused,
+    int proto __unused)
 {
 	struct pimstat pimstat, zerostat;
 	size_t len = sizeof pimstat;
 
-	if (zflag)
-		memset(&zerostat, 0, len);
-	if (sysctlbyname("net.inet.pim.stats", &pimstat, &len,
-	    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
-		if (errno != ENOENT)
-			warn("sysctl: net.inet.pim.stats");
-		return;
+	if (live) {
+		if (zflag)
+			memset(&zerostat, 0, len);
+		if (sysctlbyname("net.inet.pim.stats", &pimstat, &len,
+		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
+			if (errno != ENOENT)
+				warn("sysctl: net.inet.pim.stats");
+			return;
+		}
+	} else {
+		if (off == 0)
+			return;
+		kread(off, &pimstat, len);
 	}
 
 	printf("%s:\n", name);