Get rid of setgid kmem for systat, and while being there, fix some bugs

and compiler warnings.
The data for network statistics are still obtained via the kvm interface
if systat was started with the needed privileges, otherwise sysctls are
used. The reason for this is that with really many open sockets, the
sysctl method is probably slower, but it systat -netstat is probably not
really usable in either mode under these conditions.

Approved by:	rwatson

1 files changed, 142 insertions, 23 deletions

diff --git a/usr.bin/systat/netstat.c b/usr.bin/systat/netstat.c
index 85ee610..723f853 100644
--- a/usr.bin/systat/netstat.c
+++ b/usr.bin/systat/netstat.c
@@ -60,6 +60,7 @@ static const char rcsid[] =
 #include <netinet/tcp.h>
 #include <netinet/tcpip.h>
 #include <netinet/tcp_seq.h>
+#include <netinet/tcp_var.h>
 #define TCPSTATES
 #include <netinet/tcp_fsm.h>
 #include <netinet/tcp_timer.h>
@@ -76,7 +77,11 @@ static const char rcsid[] =
 #include "systat.h"
 #include "extern.h"
 
-static void enter __P((struct inpcb *, struct socket *, int, char *));
+static struct netinfo *enter __P((struct inpcb *, int, char *));
+static void enter_kvm __P((struct inpcb *, struct socket *, int, char *));
+static void enter_sysctl __P((struct inpcb *, struct xsocket *, int, char *));
+static void fetchnetstat_kvm __P((void));
+static void fetchnetstat_sysctl __P((void));
 static char *inetname __P((struct in_addr));
 static void inetprint __P((struct in_addr *, int, char *));
 
@@ -113,7 +118,6 @@ TAILQ_HEAD(netinfohead, netinfo) netcb = TAILQ_HEAD_INITIALIZER(netcb);
 static	int aflag = 0;
 static	int nflag = 0;
 static	int lastrow = 1;
-static	void enter(), inetprint();
 static	char *inetname();
 
 void
@@ -136,25 +140,22 @@ closenetstat(w)
 	}
 }
 
-static struct nlist namelist[] = {
+static char *miblist[] = {
+	"net.inet.tcp.pcblist",
+	"net.inet.udp.pcblist" 
+};
+
+struct nlist namelist[] = {
 #define	X_TCB	0
-	{ "_tcb" },
+	{ "tcb" },
 #define	X_UDB	1
-	{ "_udb" },
+	{ "udb" },
 	{ "" },
 };
 
 int
 initnetstat()
 {
-	if (kvm_nlist(kd, namelist)) {
-		nlisterr(namelist);
-		return(0);
-	}
-	if (namelist[X_TCB].n_value == 0) {
-		error("No symbols in namelist");
-		return(0);
-	}
 	protos = TCP|UDP;
 	return(1);
 }
@@ -162,6 +163,15 @@ initnetstat()
 void
 fetchnetstat()
 {
+	if (use_kvm)
+		fetchnetstat_kvm();
+	else
+		fetchnetstat_sysctl();
+}
+
+static void
+fetchnetstat_kvm()
+{
 	register struct inpcb *next;
 	register struct netinfo *p;
 	struct inpcbhead head;
@@ -201,9 +211,9 @@ again:
 		KREAD(inpcb.inp_socket, &sockb, sizeof (sockb));
 		if (istcp) {
 			KREAD(inpcb.inp_ppcb, &tcpcb, sizeof (tcpcb));
-			enter(&inpcb, &sockb, tcpcb.t_state, "tcp");
+			enter_kvm(&inpcb, &sockb, tcpcb.t_state, "tcp");
 		} else
-			enter(&inpcb, &sockb, 0, "udp");
+			enter_kvm(&inpcb, &sockb, 0, "udp");
 	}
 	if (istcp && (protos&UDP)) {
 		istcp = 0;
@@ -213,7 +223,84 @@ again:
 }
 
 static void
-enter(inp, so, state, proto)
+fetchnetstat_sysctl()
+{
+	register struct netinfo *p;
+	int idx;
+	struct xinpgen *inpg;
+	char *cur, *end;
+	struct inpcb *inpcb;
+	struct xinpcb *xip;
+	struct xtcpcb *xtp;
+	int plen;
+	size_t lsz;
+
+	TAILQ_FOREACH(p, &netcb, chain)
+		p->ni_seen = 0;
+	if (protos&TCP) {
+		idx = 0;
+	} else if (protos&UDP) {
+		idx = 1;
+	} else {
+		error("No protocols to display");
+		return;
+	}
+
+	for (;idx < 2; idx++) {
+		if (idx == 1 && !(protos&UDP))
+			break;
+		inpg = (struct xinpgen *)sysctl_dynread(miblist[idx], &lsz);
+		if (inpg == NULL) {
+			error("sysctl(%s...) failed", miblist[idx]);
+			continue;
+		}
+		/* 
+		 * We currently do no require a consistent pcb list.
+		 * Try to be robust in case of struct size changes 
+		 */
+		cur = ((char *)inpg) + inpg->xig_len;
+		/* There is also a trailing struct xinpgen */
+		end = ((char *)inpg) + lsz - inpg->xig_len;
+		if (end <= cur) {
+			free(inpg);
+			continue;
+		}
+		if (idx == 0) { /* TCP */
+			xtp = (struct xtcpcb *)cur;
+			plen = xtp->xt_len;
+		} else {
+			xip = (struct xinpcb *)cur;
+			plen = xip->xi_len;
+		}
+		while (cur + plen <= end) {
+			if (idx == 0) { /* TCP */
+				xtp = (struct xtcpcb *)cur;
+				inpcb = &xtp->xt_inp;
+			} else {
+				xip = (struct xinpcb *)cur;
+				inpcb = &xip->xi_inp;
+			}
+			cur += plen;
+
+			if (!aflag && inet_lnaof(inpcb->inp_laddr) == 
+			    INADDR_ANY)
+				continue;
+			if (nhosts && !checkhost(inpcb))
+				continue;
+			if (nports && !checkport(inpcb))
+				continue;
+			if (idx == 0)	/* TCP */
+				enter_sysctl(inpcb, &xtp->xt_socket, 
+				    xtp->xt_tp.t_state, "tcp");
+			else		/* UDP */
+				enter_sysctl(inpcb, &xip->xi_socket, 0, "udp");
+		}
+		free(inpg);
+	}
+}
+
+static void
+enter_kvm(inp, so, state, proto)
 	register struct inpcb *inp;
 	register struct socket *so;
 	int state;
@@ -221,6 +308,36 @@ enter(inp, so, state, proto)
 {
 	register struct netinfo *p;
 
+	if ((p = enter(inp, state, proto)) != NULL) {
+		p->ni_rcvcc = so->so_rcv.sb_cc;
+		p->ni_sndcc = so->so_snd.sb_cc;
+	}
+}
+
+static void
+enter_sysctl(inp, so, state, proto)
+	register struct inpcb *inp;
+	register struct xsocket *so;
+	int state;
+	char *proto;
+{
+	register struct netinfo *p;
+
+	if ((p = enter(inp, state, proto)) != NULL) {
+		p->ni_rcvcc = so->so_rcv.sb_cc;
+		p->ni_sndcc = so->so_snd.sb_cc;
+	}
+}
+
+
+static struct netinfo *
+enter(inp, state, proto)
+	register struct inpcb *inp;
+	int state;
+	char *proto;
+{
+	register struct netinfo *p;
+
 	/*
 	 * Only take exact matches, any sockets with
 	 * previously unbound addresses will be deleted
@@ -241,7 +358,7 @@ enter(inp, so, state, proto)
 	if (p == NULL) {
 		if ((p = malloc(sizeof(*p))) == NULL) {
 			error("Out of memory");
-			return;
+			return NULL;
 		}
 		TAILQ_INSERT_HEAD(&netcb, p, chain);
 		p->ni_line = -1;
@@ -252,10 +369,9 @@ enter(inp, so, state, proto)
 		p->ni_proto = proto;
 		p->ni_flags = NIF_LACHG|NIF_FACHG;
 	}
-	p->ni_rcvcc = so->so_rcv.sb_cc;
-	p->ni_sndcc = so->so_snd.sb_cc;
 	p->ni_state = state;
 	p->ni_seen = 1;
+	return p;
 }
 
 /* column locations */
@@ -270,7 +386,7 @@ enter(inp, so, state, proto)
 void
 labelnetstat()
 {
-	if (namelist[X_TCB].n_type == 0)
+	if (use_kvm && namelist[X_TCB].n_type == 0)
 		return;
 	wmove(wnd, 0, 0); wclrtobot(wnd);
 	mvwaddstr(wnd, 0, LADDR, "Local Address");
@@ -291,9 +407,12 @@ shownetstat()
 	 * away and adjust the position of connections
 	 * below to reflect the deleted line.
 	 */
-	TAILQ_FOREACH(p, &netcb, chain) {
-		if (p->ni_line == -1 || p->ni_seen)
+	p = TAILQ_FIRST(&netcb);
+	while (p != NULL) {
+		if (p->ni_line == -1 || p->ni_seen) {
+			p = TAILQ_NEXT(p, chain);
 			continue;
+		}
 		wmove(wnd, p->ni_line, 0); wdeleteln(wnd);
 		TAILQ_FOREACH(q, &netcb, chain)
 			if (q != p && q->ni_line > p->ni_line) {
@@ -302,7 +421,7 @@ shownetstat()
 				q->ni_flags |= NIF_LACHG|NIF_FACHG;
 			}
 		lastrow--;
-		q = TAILQ_PREV(p, netinfohead, chain);
+		q = TAILQ_NEXT(p, chain);
 		TAILQ_REMOVE(&netcb, p, chain);
 		free(p);
 		p = q;