From: Roy Marples <roy@marples.name>
Date: Tue, 20 Aug 2019 21:59:47 +0000 (+0100)
Subject: Linux: Add support for ARPHRD_NONE
X-Git-Tag: v8.0.3~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=208b25190faffe0735c19e69c03e122e5c54dfbf;p=thirdparty%2Fdhcpcd.git

Linux: Add support for ARPHRD_NONE

So apprently I've been doing this wrong for years - on glibc at
least, getifaddrs(3) never reported a hardware address for
AF_PACKET addresses. Infact, it reported nothing but useless
stats in ifa_data.

I view this as a bug because SIOCGIFHWADDR will get a sockaddr
with a sa_family set correctly. getifaddrs should do the same.
Anyway, if we have the ioctl and no address for the AF_PACKET
"address", call upon the above ioctl to get the correct family
for the interface.

While here, replace if_nametoindex with an ioctl to save libc
from doing it for us.
---

diff --git a/src/bpf.c b/src/bpf.c
index 10404ffe..06bbf3f1 100644
--- a/src/bpf.c
+++ b/src/bpf.c
@@ -558,13 +558,13 @@ bpf_arp(struct interface *ifp, int fd)
 #define	BPF_M_UDP	3
 #define	BPF_M_UDPLEN	4
 
-#ifdef ARPHRD_NETROM
-static const struct bpf_insn bpf_bootp_netrom[] = {
+#ifdef ARPHRD_NONE
+static const struct bpf_insn bpf_bootp_none[] = {
 	/* Set the frame header length to zero. */
 	BPF_STMT(BPF_LD + BPF_IMM, 0),
 	BPF_STMT(BPF_ST, BPF_M_FHLEN),
 };
-#define BPF_BOOTP_NETROM_LEN	__arraycount(bpf_bootp_netrom)
+#define BPF_BOOTP_NONE_LEN	__arraycount(bpf_bootp_none)
 #endif
 
 static const struct bpf_insn bpf_bootp_ether[] = {
@@ -674,10 +674,10 @@ bpf_bootp(struct interface *ifp, int fd)
 	bp = bpf;
 	/* Check frame header. */
 	switch(ifp->family) {
-#ifdef ARPHRD_NETROM
-	case ARPHRD_NETROM:
-		memcpy(bp, bpf_bootp_netrom, sizeof(bpf_bootp_netrom));
-		bp += BPF_BOOTP_NETROM_LEN;
+#ifdef ARPHRD_NONE
+	case ARPHRD_NONE:
+		memcpy(bp, bpf_bootp_none, sizeof(bpf_bootp_none));
+		bp += BPF_BOOTP_NONE_LEN;
 		break;
 #endif
 	case ARPHRD_ETHER:
diff --git a/src/duid.c b/src/duid.c
index 60e4be37..d6c2b498 100644
--- a/src/duid.c
+++ b/src/duid.c
@@ -52,10 +52,6 @@
 #include <time.h>
 #include <unistd.h>
 
-#ifndef ARPHRD_NETROM
-#  define ARPHRD_NETROM	0
-#endif
-
 #include "common.h"
 #include "dhcpcd.h"
 #include "duid.h"
@@ -189,10 +185,10 @@ duid_get(uint8_t **d, const struct interface *ifp)
 		return len;
 
 	/* No UUID? OK, lets make one based on our interface */
-	if (ifp->family == ARPHRD_NETROM) {
-		logwarnx("%s: is a NET/ROM pseudo interface", ifp->name);
+	if (ifp->hwlen == 0) {
+		logwarnx("%s: does not have hardware address", ifp->name);
 		TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) {
-			if (ifp2->family != ARPHRD_NETROM)
+			if (ifp2->hwlen != 0)
 				break;
 		}
 		if (ifp2) {
diff --git a/src/if.c b/src/if.c
index 857294ef..d9f5d19f 100644
--- a/src/if.c
+++ b/src/if.c
@@ -307,17 +307,16 @@ if_discover(struct dhcpcd_ctx *ctx, struct ifaddrs **ifaddrs,
 	struct if_spec spec;
 #ifdef AF_LINK
 	const struct sockaddr_dl *sdl;
-#ifdef SIOCGIFPRIORITY
-	struct ifreq ifr;
-#endif
 #ifdef IFLR_ACTIVE
 	struct if_laddrreq iflr = { .flags = IFLR_PREFIX };
 	int link_fd;
 #endif
-
 #elif AF_PACKET
 	const struct sockaddr_ll *sll;
 #endif
+#if defined(SIOCGIFPRIORITY) || defined(SIOCGIFHWADDR)
+	struct ifreq ifr;
+#endif
 
 	if ((ifs = malloc(sizeof(*ifs))) == NULL) {
 		logerr(__func__);
@@ -512,10 +511,18 @@ if_discover(struct dhcpcd_ctx *ctx, struct ifaddrs **ifaddrs,
 				memcpy(ifp->hwaddr, sll->sll_addr, ifp->hwlen);
 #endif
 		}
-#ifdef __linux__
-		/* PPP addresses on Linux don't have hardware addresses */
-		else
-			ifp->index = if_nametoindex(ifp->name);
+#ifdef SIOCGIFHWADDR
+		else {
+			memset(&ifr, 0, sizeof(ifr));
+			strlcpy(ifr.ifr_name, ifa->ifa_name,
+			    sizeof(ifr.ifr_name));
+			if (ioctl(ctx->pf_inet_fd, SIOCGIFHWADDR, &ifr) == -1)
+				logerr("%s: SIOCGIFHWADDR", ifa->ifa_name);
+			ifp->family = ifr.ifr_hwaddr.sa_family;
+			if (ioctl(ctx->pf_inet_fd, SIOCGIFINDEX, &ifr) == -1)
+				logerr("%s: SIOCGIFINDEX", ifa->ifa_name);
+			ifp->index = (unsigned int)ifr.ifr_ifindex;
+		}
 #endif
 
 		/* Ensure hardware address is valid. */
@@ -528,9 +535,6 @@ if_discover(struct dhcpcd_ctx *ctx, struct ifaddrs **ifaddrs,
 			    ctx->ifac == 0 && !if_hasconf(ctx, ifp->name))
 				active = IF_INACTIVE;
 			switch (ifp->family) {
-#ifdef ARPHRD_NETROM
-			case ARPHRD_NETROM:
-#endif
 			case ARPHRD_IEEE1394:
 			case ARPHRD_INFINIBAND:
 #ifdef ARPHRD_LOOPBACK
@@ -538,6 +542,9 @@ if_discover(struct dhcpcd_ctx *ctx, struct ifaddrs **ifaddrs,
 #endif
 #ifdef ARPHRD_PPP
 			case ARPHRD_PPP:
+#endif
+#ifdef ARPHRD_NONE
+			case ARPHRD_NONE:
 #endif
 				/* We don't warn for supported families */
 				break;