libifconfig: Add an SR-IOV VF status query

Provide a public helper which retrieves, unpacks, and validates the
versioned VF status nvlist.  Validate the required VF indices and the
shape and version of driver-specific extension namespaces while allowing
unknown optional fields.

The ioctl argument is not copied back when the command returns EFBIG.
Start with a practical buffer and grow it geometrically rather than
relying on the required length being observable.

Use the helper in ifconfig so other consumers share the same transport
and validation behavior.

lib/libifconfig/Makefile

@@ -1,7 +1,7 @@
 LIB=		ifconfig
 INTERNALLIB=	true
 
-LIBADD=		m
+LIBADD=		m nv
 
 SHLIBDIR?=	/lib
 SHLIB_MAJOR=	2

lib/libifconfig/Symbol.map

@@ -84,3 +84,7 @@ FBSD_1.6 {
 	ifconfig_sfp_rev_description;
 	ifconfig_sfp_rev_symbol;
 };
+
+FBSD_1.9 {
+	ifconfig_get_vf_status;
+};

lib/libifconfig/libifconfig.c

@@ -529,6 +529,135 @@ ifconfig_get_ifstatus(ifconfig_handle_t *h, const char *name,
 	return (ifconfig_ioctlwrap(h, AF_LOCAL, SIOCGIFSTATUS, ifs));
 }
 
+static int
+ifconfig_vf_status_validate(const nvlist_t *status)
+{
+	const nvlist_t * const *vfs;
+	const nvlist_t *extensions, *vf;
+	const char *name;
+	void *cookie;
+	size_t i, num_vfs;
+	int type;
+
+	if (!nvlist_exists_number(status, IFVF_STATUS_VERSION_KEY))
+		return (EBADMSG);
+	if (nvlist_get_number(status, IFVF_STATUS_VERSION_KEY) !=
+	    IFVF_STATUS_VERSION)
+		return (EPROTONOSUPPORT);
+	if (!nvlist_exists_nvlist_array(status, IFVF_STATUS_VFS))
+		return (EBADMSG);
+
+	vfs = nvlist_get_nvlist_array(status, IFVF_STATUS_VFS, &num_vfs);
+	for (i = 0; i < num_vfs; i++) {
+		vf = vfs[i];
+		if (!nvlist_exists_number(vf, IFVF_STATUS_INDEX))
+			return (EBADMSG);
+		if (!nvlist_exists(vf, IFVF_STATUS_EXTENSIONS))
+			continue;
+		if (!nvlist_exists_nvlist(vf, IFVF_STATUS_EXTENSIONS))
+			return (EBADMSG);
+		extensions = nvlist_get_nvlist(vf, IFVF_STATUS_EXTENSIONS);
+		cookie = NULL;
+		while ((name = nvlist_next(extensions, &type, &cookie)) != NULL) {
+			if (type != NV_TYPE_NVLIST)
+				return (EBADMSG);
+			if (!nvlist_exists_number(nvlist_get_nvlist(extensions,
+			    name), IFVF_STATUS_EXT_VERSION))
+				return (EBADMSG);
+		}
+	}
+	return (0);
+}
+
+int
+ifconfig_get_vf_status(ifconfig_handle_t *h, const char *name,
+    nvlist_t **statusp)
+{
+	struct ifreq ifr;
+	nvlist_t *status;
+	void *buf, *newbuf;
+	size_t namelen;
+	u_int buflen, nextlen;
+	int error;
+
+	if (h == NULL || name == NULL || statusp == NULL) {
+		if (h != NULL)
+			ifconfig_error(h, OTHER, EINVAL);
+		return (-1);
+	}
+	*statusp = NULL;
+	namelen = strnlen(name, IFNAMSIZ);
+	if (namelen == IFNAMSIZ) {
+		ifconfig_error(h, OTHER, ENAMETOOLONG);
+		return (-1);
+	}
+
+	/*
+	 * ioctl(2) does not copy an _IOWR argument back to userspace when the
+	 * command returns EFBIG, so the kernel's required length is not
+	 * observable on a short-buffer error.  Start with enough space for the
+	 * common case and grow geometrically instead of relying on length.
+	 */
+	buflen = 16 * 1024;
+	buf = malloc(buflen);
+	if (buf == NULL) {
+		ifconfig_error(h, OTHER, ENOMEM);
+		return (-1);
+	}
+	for (;;) {
+		memset(&ifr, 0, sizeof(ifr));
+		memcpy(ifr.ifr_name, name, namelen + 1);
+		ifr.ifr_vf_status_nv.buffer = buf;
+		ifr.ifr_vf_status_nv.buf_length = buflen;
+		if (ifconfig_ioctlwrap(h, AF_LOCAL, SIOCGIFVFSTATUS, &ifr) == 0)
+			break;
+		if (ifconfig_err_errno(h) != EFBIG ||
+		    buflen == IFR_VF_STATUS_NV_MAXBUFSIZE ||
+		    ifr.ifr_vf_status_nv.length >
+		    IFR_VF_STATUS_NV_MAXBUFSIZE) {
+			free(buf);
+			return (-1);
+		}
+		if (ifr.ifr_vf_status_nv.length > buflen)
+			nextlen = ifr.ifr_vf_status_nv.length;
+		else if (buflen > IFR_VF_STATUS_NV_MAXBUFSIZE / 2)
+			nextlen = IFR_VF_STATUS_NV_MAXBUFSIZE;
+		else
+			nextlen = buflen * 2;
+		newbuf = realloc(buf, nextlen);
+		if (newbuf == NULL) {
+			free(buf);
+			ifconfig_error(h, OTHER, ENOMEM);
+			return (-1);
+		}
+		buf = newbuf;
+		buflen = nextlen;
+	}
+
+	if (ifr.ifr_vf_status_nv.length == 0 ||
+	    ifr.ifr_vf_status_nv.length > buflen) {
+		free(buf);
+		ifconfig_error(h, OTHER, EBADMSG);
+		return (-1);
+	}
+	status = nvlist_unpack(buf, ifr.ifr_vf_status_nv.length, 0);
+	free(buf);
+	if (status == NULL) {
+		ifconfig_error(h, OTHER, EBADMSG);
+		return (-1);
+	}
+	error = ifconfig_vf_status_validate(status);
+	if (error != 0) {
+		nvlist_destroy(status);
+		ifconfig_error(h, OTHER, error);
+		return (-1);
+	}
+
+	ifconfig_error_clear(h);
+	*statusp = status;
+	return (0);
+}
+
 int
 ifconfig_destroy_interface(ifconfig_handle_t *h, const char *name)
 {

lib/libifconfig/libifconfig.h

@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <sys/nv.h>
 #include <sys/types.h>
 
 #include <net/if.h>
@@ -198,6 +199,16 @@ int ifconfig_get_groups(ifconfig_handle_t *h, const char *name,
 int ifconfig_get_ifstatus(ifconfig_handle_t *h, const char *name,
     struct ifstat *stat);
 
+/** Retrieve structured SR-IOV VF status for an interface.
+ * @param h	An open ifconfig state object
+ * @param name	The PF interface name
+ * @param statusp Return argument.  The caller owns the returned nvlist and
+ *                must destroy it with nvlist_destroy().
+ * @return	0 on success, -1 on failure
+ */
+int ifconfig_get_vf_status(ifconfig_handle_t *h, const char *name,
+    nvlist_t **statusp);
+
 /** Retrieve the interface media information
  * @param h	An open ifconfig state object
  * @param name	The interface name

sbin/ifconfig/ifvfstatus.c

@@ -27,9 +27,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <sys/ioctl.h>
 #include <sys/nv.h>
-#include <sys/socket.h>
 
 #include <net/ethernet.h>
 #include <net/if.h>
@@ -37,7 +35,6 @@
 #include <err.h>
 #include <errno.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
 #include "ifconfig.h"
@@ -63,64 +60,21 @@ vf_status(if_ctx *ctx)
 {
 	const nvlist_t * const *vfs;
 	const nvlist_t *vf;
-	struct ifreq ifr;
 	const void *mac;
 	nvlist_t *status;
 	const char *mode, *state;
 	size_t maclen, num_vfs;
 	uint64_t speed;
-	void *buf, *newbuf;
-	u_int buflen, nextlen;
 	bool printed;
+	int error;
 
-	buflen = 16 * 1024;
-	buf = malloc(buflen);
-	if (buf == NULL)
-		err(1, "malloc");
-	for (;;) {
-		memset(&ifr, 0, sizeof(ifr));
-		strlcpy(ifr.ifr_name, ctx->ifname, sizeof(ifr.ifr_name));
-		ifr.ifr_vf_status_nv.buffer = buf;
-		ifr.ifr_vf_status_nv.buf_length = buflen;
-		if (ioctl_ctx(ctx, SIOCGIFVFSTATUS, &ifr) == 0)
-			break;
-		if (errno == EINVAL || errno == ENOTTY || errno == ENXIO ||
-		    errno == ENOTSUP || errno == EOPNOTSUPP) {
-			free(buf);
+	if (ifconfig_get_vf_status(lifh, ctx->ifname, &status) != 0) {
+		error = ifconfig_err_errno(lifh);
+		if (error == EINVAL || error == ENOTTY || error == ENXIO ||
+		    error == ENOTSUP || error == EOPNOTSUPP)
 			return;
-		}
-		if (errno != EFBIG ||
-		    buflen == IFR_VF_STATUS_NV_MAXBUFSIZE ||
-		    ifr.ifr_vf_status_nv.length >
-		    IFR_VF_STATUS_NV_MAXBUFSIZE) {
-			free(buf);
-			warn("SIOCGIFVFSTATUS");
-			return;
-		}
-		if (ifr.ifr_vf_status_nv.length > buflen)
-			nextlen = ifr.ifr_vf_status_nv.length;
-		else if (buflen > IFR_VF_STATUS_NV_MAXBUFSIZE / 2)
-			nextlen = IFR_VF_STATUS_NV_MAXBUFSIZE;
-		else
-			nextlen = buflen * 2;
-		newbuf = realloc(buf, nextlen);
-		if (newbuf == NULL) {
-			free(buf);
-			err(1, "realloc");
-		}
-		buf = newbuf;
-		buflen = nextlen;
-	}
-
-	status = nvlist_unpack(buf, ifr.ifr_vf_status_nv.length, 0);
-	free(buf);
-	if (status == NULL ||
-	    !nvlist_exists_number(status, IFVF_STATUS_VERSION_KEY) ||
-	    nvlist_get_number(status, IFVF_STATUS_VERSION_KEY) !=
-	    IFVF_STATUS_VERSION ||
-	    !nvlist_exists_nvlist_array(status, IFVF_STATUS_VFS)) {
-		warnx("SIOCGIFVFSTATUS returned an unsupported format");
-		nvlist_destroy(status);
+		errno = error;
+		warn("SIOCGIFVFSTATUS");
 		return;
 	}
 

share/mk/src.libnames.mk

@@ -379,7 +379,7 @@ _DP_gmock=	gtest
 _DP_gmock_main=	gmock
 _DP_gtest=	pthread regex
 _DP_gtest_main=	gtest
-_DP_ifconfig=	m
+_DP_ifconfig=	m nv
 _DP_ipf=	kvm
 _DP_iscsiutil=	md
 _DP_kldelf=	elf
@@ -512,7 +512,7 @@ _DP_zpool=	md pthread z icp spl nvpair avl umem
 _DP_zutil=	avl geom m
 _DP_be=		zfs spl nvpair zfsbootenv
 _DP_netmap=
-_DP_ifconfig=	m
+_DP_ifconfig=	m nv
 _DP_pfctl=	nv
 _DP_krb5ss=		edit