Change this to support the new way swap device information is exported

via sysctl, and clean up some style and (size_t != int) issues.

1 files changed, 66 insertions, 77 deletions

diff --git a/lib/libkvm/kvm_getswapinfo.c b/lib/libkvm/kvm_getswapinfo.c
index 386df18..d23045f 100644
--- a/lib/libkvm/kvm_getswapinfo.c
+++ b/lib/libkvm/kvm_getswapinfo.c
@@ -27,7 +27,10 @@ static const char rcsid[] =
 #include <sys/blist.h>
 #include <sys/sysctl.h>
 
+#include <vm/vm_param.h>
+
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <kvm.h>
 #include <nlist.h>
@@ -65,9 +68,7 @@ static int kvm_getswapinfo2(kvm_t *kd, struct kvm_swap *swap_ary,
 static int  kvm_getswapinfo_kvm(kvm_t *, struct kvm_swap *, int, int);
 static int  kvm_getswapinfo_sysctl(kvm_t *, struct kvm_swap *, int, int);
 static int  nlist_init(kvm_t *);
-static int  getsysctl(kvm_t *, char *, void *, int);
-static int  getsysctl2(kvm_t *, char *, char *,  char *, int, void *, int);
-
+static int  getsysctl(kvm_t *, char *, void *, size_t);
 
 #define	SVAR(var) __STRING(var)	/* to force expansion */
 #define	KGET(idx, var)							\
@@ -89,15 +90,15 @@ static int  getsysctl2(kvm_t *, char *, char *,  char *, int, void *, int);
 		return (0);						\
 	}
 
-#define GETSWDEVNAME(dev, str, flags)                                   \
-        if (dev == NODEV) {                                             \
-	        strlcpy(str, "[NFS swap]", sizeof(str));                \
-	} else {                                                        \
-		snprintf(                                               \
-                    str, sizeof(str),"%s%s",                            \
-		    ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""),       \
-		    devname(dev, S_IFCHR)                               \
-		);                                                      \
+#define GETSWDEVNAME(dev, str, flags)					\
+	if (dev == NODEV) {						\
+		strlcpy(str, "[NFS swap]", sizeof(str));		\
+	} else {							\
+		snprintf(						\
+		    str, sizeof(str),"%s%s",				\
+		    ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""),	\
+		    devname(dev, S_IFCHR)				\
+		);							\
 	}
 
 int
@@ -458,11 +459,11 @@ getswapinfo_radix(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags)
 	);
 }
 
-#define GETSYSCTL(kd, name, var)                                        \
-            getsysctl(kd, name, &(var), sizeof(var))
-#define GETSYSCTL2(kd, pref, suff, buf, var)                            \
-            getsysctl2(kd, pref, suff, buf, sizeof(buf), &(var),        \
-	    sizeof(var))
+#define	GETSYSCTL(kd, name, var)					\
+	    getsysctl(kd, name, &(var), sizeof(var))
+
+/* The maximum MIB length for vm.swap_info and an additional device number */
+#define	SWI_MAXMIB	3
 
 int
 kvm_getswapinfo_sysctl(
@@ -471,54 +472,62 @@ kvm_getswapinfo_sysctl(
 	int swap_max, 
 	int flags
 ) {
-	int ti = 0;
-	udev_t dev;
-	char node[15];
-	char buf[20];
-	int used, ttl, i;
-
-	if (!GETSYSCTL(kd, "vm.nswapdev", unswdev))
-		return -1;
-
-	ti = unswdev;
-	if (ti >= swap_max)
-		ti = swap_max - 1;
-	
-	if (ti >= 0)
-		bzero(swap_ary, sizeof(struct kvm_swap) * (ti + 1));
+	int ti, ttl;
+	size_t mibi, len;
+	int soid[SWI_MAXMIB];
+	struct xswdev xsd;
+	struct kvm_swap tot;
 
 	if (!GETSYSCTL(kd, "vm.dmmax", dmmax))
 		return -1;
 
-	for (i = 0; i < unswdev; ++i) {
-		if (snprintf(node, sizeof(node), "vm.swapdev%d.", i) >=
-		    sizeof(node)) {
-			_kvm_err(kd, kd->program, "XXX: node buffer too small");
+	mibi = SWI_MAXMIB - 1;
+	if (sysctlnametomib("vm.swap_info", soid, &mibi) == -1) {
+		_kvm_err(kd, kd->program, "sysctlnametomib failed: %s",
+		    strerror(errno));
+		return -1;
+	}
+	bzero(&tot, sizeof(tot));
+	for (unswdev = 0;; unswdev++) {
+		soid[mibi] = unswdev;
+		len = sizeof(xsd);
+		if (sysctl(soid, mibi + 1, &xsd, &len, NULL, 0) == -1) {
+			if (errno == ENOENT)
+				break;
+			_kvm_err(kd, kd->program, "cannot read sysctl: %s.",
+			    strerror(errno));
 			return -1;
 		}
-
-		if (!GETSYSCTL2(kd, node, "nblks", buf, ttl))
+		if (len != sizeof(xsd)) {
+			_kvm_err(kd, kd->program, "struct xswdev has unexpected "
+			    "size;  kernel and libkvm out of sync?");
 			return -1;
-		if (!GETSYSCTL2(kd, node, "used", buf, used))
+		}
+		if (xsd.xsw_version != XSWDEV_VERSION) {
+			_kvm_err(kd, kd->program, "struct xswdev version "
+			    "mismatch; kernel and libkvm out of sync?");
 			return -1;
-		ttl -= dmmax;
-
-		if (i < ti) {
-			if (!GETSYSCTL2(kd, node, "dev", buf, dev))
-				return -1;
-			if (!GETSYSCTL2(kd, node, "flags", buf,	
-					swap_ary[i].ksw_flags))
-				return -1;
-			swap_ary[i].ksw_total = ttl;
-			swap_ary[i].ksw_used = used;
-			GETSWDEVNAME(dev, swap_ary[i].ksw_devname, flags);
 		}
-		if (ti >= 0) {
-			swap_ary[ti].ksw_total += ttl;
-			swap_ary[ti].ksw_used += used;
+
+		ttl = xsd.xsw_nblks - dmmax;
+		if (unswdev < swap_max - 1) {
+			bzero(&swap_ary[unswdev], sizeof(swap_ary[unswdev]));
+			swap_ary[unswdev].ksw_total = ttl;
+			swap_ary[unswdev].ksw_used = xsd.xsw_used;
+			swap_ary[unswdev].ksw_flags = xsd.xsw_flags;
+			GETSWDEVNAME(xsd.xsw_dev, swap_ary[unswdev].ksw_devname,
+			     flags);
 		}
+		tot.ksw_total += ttl;
+		tot.ksw_used += xsd.xsw_used;
 	}
 
+	ti = unswdev;
+	if (ti >= swap_max)
+		ti = swap_max - 1;
+	if (ti >= 0)
+		swap_ary[ti] = tot;
+
         return(ti);
 }
 
@@ -574,11 +583,12 @@ getsysctl (
 	kvm_t *kd,
 	char *name,
 	void *ptr,
-	int len
+	size_t len
 ) {
-	int nlen = len;
+	size_t nlen = len;
 	if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
-		_kvm_err(kd, kd->program, "cannot read sysctl %s", name);
+		_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
+		    strerror(errno));
 		return (0);
 	}
 	if (nlen != len) {
@@ -587,24 +597,3 @@ getsysctl (
 	}
 	return (1);
 }
-
-static int
-getsysctl2 (
-	kvm_t *kd,
-	char *pref,
-	char *suff,
-	char *buf,
-	int buflen,
-	void *ptr,
-	int len
-) {
-	if (strlcpy(buf, pref, buflen) >= buflen) {
-		_kvm_err(kd, kd->program, "getsysctl2: string buffer too small");
-		return (0);
-	}
-	if (strlcat(buf, suff, buflen) >= buflen) {
-		_kvm_err(kd, kd->program, "getsysctl2: string buffer too small");
-		return (0);
-	}
-	return getsysctl(kd, buf, ptr, len);
-}