Add a new leaf to the net.link.generic.ifdata.%d sysctl to retrieve

the name and unit number assigned by the driver. This is needed by
SNMP to find interfaces after they have been renamed.

MFC after:	4 weeks

3 files changed, 44 insertions, 5 deletions

diff --git a/sys/net/if_mib.c b/sys/net/if_mib.c
index c061e7f..dc2b8e1 100644
--- a/sys/net/if_mib.c
+++ b/sys/net/if_mib.c
@@ -75,6 +75,8 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
 	u_int namelen = arg2;
 	struct ifnet *ifp;
 	struct ifmibdata ifmd;
+	size_t dlen;
+	char *dbuf;
 
 	if (namelen != 2)
 		return EINVAL;
@@ -134,7 +136,22 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
 		error = SYSCTL_IN(req, ifp->if_linkmib, ifp->if_linkmiblen);
 		if (error)
 			return error;
-		
+
+	case IFDATA_DRIVERNAME:
+		/* 20 is enough for 64bit ints */
+		dlen = strlen(ifp->if_dname) + 20 + 1;
+		if ((dbuf = malloc(dlen, M_TEMP, M_NOWAIT)) == NULL)
+			return (ENOMEM);
+		if (ifp->if_dunit == IF_DUNIT_NONE)
+			strcpy(dbuf, ifp->if_dname);
+		else
+			sprintf(dbuf, "%s%d", ifp->if_dname, ifp->if_dunit);
+
+		error = SYSCTL_OUT(req, dbuf, strlen(dbuf) + 1);
+		if (error == 0 && req->newptr != NULL)
+			error = EPERM;
+		free(dbuf, M_TEMP);
+		return (error);
 	}
 	return 0;
 }
diff --git a/sys/net/if_mib.h b/sys/net/if_mib.h
index 445bd5b..e2b80c8 100644
--- a/sys/net/if_mib.h
+++ b/sys/net/if_mib.h
@@ -54,6 +54,7 @@ struct ifmibdata {
  */
 #define	IFDATA_GENERAL	1	/* generic stats for all kinds of ifaces */
 #define	IFDATA_LINKSPECIFIC	2 /* specific to the type of interface */
+#define	IFDATA_DRIVERNAME	3 /* driver name and unit */
 
 /*
  * MIB tags at the net.link.generic.system level
diff --git a/tools/tools/ifinfo/ifinfo.c b/tools/tools/ifinfo/ifinfo.c
index 54ca164..22053c5 100644
--- a/tools/tools/ifinfo/ifinfo.c
+++ b/tools/tools/ifinfo/ifinfo.c
@@ -47,7 +47,7 @@
 
 #include "ifinfo.h"
 
-static void printit(const struct ifmibdata *);
+static void printit(const struct ifmibdata *, const char *);
 static const char *iftype(int);
 static const char *ifphys(int, int);
 static int isit(int, char **, const char *);
@@ -72,6 +72,7 @@ main(int argc, char **argv)
 	void *linkmib;
 	size_t linkmiblen;
 	printfcn pf;
+	char *dname;
 
 	while ((c = getopt(argc, argv, "l")) != -1) {
 		switch(c) {
@@ -110,7 +111,24 @@ main(int argc, char **argv)
 
 		if (!isit(argc - optind, argv + optind, ifmd.ifmd_name))
 			continue;
-		printit(&ifmd);
+
+		dname = NULL;
+		len = 0;
+		name[5] = IFDATA_DRIVERNAME;
+		if (sysctl(name, 6, NULL, &len, 0, 0) < 0) {
+			warn("sysctl(net.link.ifdata.%d.drivername)", i);
+		} else {
+			if ((dname = malloc(len)) == NULL)
+				err(EX_OSERR, NULL);
+			if (sysctl(name, 6, dname, &len, 0, 0) < 0) {
+				warn("sysctl(net.link.ifdata.%d.drivername)",
+				    i);
+				free(dname);
+				dname = NULL;
+			}
+		}
+		printit(&ifmd, dname);
+		free(dname);
 		if (dolink && (pf = findlink(ifmd.ifmd_data.ifi_type))) {
 			name[5] = IFDATA_LINKSPECIFIC;
 			if (sysctl(name, 6, 0, &linkmiblen, 0, 0) < 0)
@@ -135,9 +153,12 @@ main(int argc, char **argv)
 }
 
 static void
-printit(const struct ifmibdata *ifmd)
+printit(const struct ifmibdata *ifmd, const char *dname)
 {
-	printf("Interface %.*s:\n", IFNAMSIZ, ifmd->ifmd_name);
+	printf("Interface %.*s", IFNAMSIZ, ifmd->ifmd_name);
+	if (dname != NULL)
+		printf(" (%s)", dname);
+	printf(":\n");
 	printf("\tflags: %x\n", ifmd->ifmd_flags);
 	printf("\tpromiscuous listeners: %d\n", ifmd->ifmd_pcount);
 	printf("\tsend queue length: %d\n", ifmd->ifmd_snd_len);