[PATCH] increase MAX_ADDR_LEN

Roland Dreier (roland@topspin.com)
31 Dec 2002 15:11:31 -0800


The patch included below is intended to increase MAX_ADDR_LEN to 32,
which will make adding IP-over-InfiniBand support much simpler.

I included the rtnetlink-based support for big hardware adresses that
we discussed earlier. Specifically, the patch:

1. Adds ARPHRD_INFINIBAND to if_arp.h. This is extremely minor, but
will make an IP-over-InfiniBand driver cleaner.

2. Increases MAX_ADDR_LEN to 32 (from 8).

3. Makes some small changes to net/core/dev.c to prevent the
increased MAX_ADDR_LEN from overflowing when the SIOCGIFHWADDR
and SIOCSIFHWADDR ioctls are used on interfaces with addr_len >
14 (the size of sa_data in struct sockaddr).

4. Adds RTM_SETLINK to <linux/rtnetlink.h> and adds a function
do_setlink() to net/core/rtnetlink.c to handle this message from
userspace. This lets userspace set the hardware address and
broadcast address for interfaces with addr_len > 14.

5. Cleans up the initializer for link_rtnetlink_table[] so that it
is much easier to read and change.

There is some suspicious-looking use of MAX_ADDR_LEN in
drivers/net/sungem.c and drivers/s390/net/lcs.c but I did not touch
those files in this patch.

This patch was created and tested with UML on kernel 2.5.47, but
applies cleanly to Linus's current 2.5.53-BK (with a few offsets).

Please apply this patch or let me know what needs to change for it to
be applied.

Thanks,
Roland <roland@topspin.com>

diff -Naur linux-2.5.47/include/linux/if_arp.h linux-2.5.47-max-addr/include/linux/if_arp.h
--- linux-2.5.47/include/linux/if_arp.h Sun Nov 10 19:28:29 2002
+++ linux-2.5.47-max-addr/include/linux/if_arp.h Mon Dec 30 13:50:07 2002
@@ -40,6 +40,7 @@
#define ARPHRD_METRICOM 23 /* Metricom STRIP (new IANA id) */
#define ARPHRD_IEEE1394 24 /* IEEE 1394 IPv4 - RFC 2734 */
#define ARPHRD_EUI64 27 /* EUI-64 */
+#define ARPHRD_INFINIBAND 32 /* InfiniBand */

/* Dummy types for non ARP hardware */
#define ARPHRD_SLIP 256
diff -Naur linux-2.5.47/include/linux/netdevice.h linux-2.5.47-max-addr/include/linux/netdevice.h
--- linux-2.5.47/include/linux/netdevice.h Sun Nov 10 19:28:31 2002
+++ linux-2.5.47-max-addr/include/linux/netdevice.h Mon Dec 30 12:05:42 2002
@@ -65,7 +65,7 @@

#endif

-#define MAX_ADDR_LEN 8 /* Largest hardware address length */
+#define MAX_ADDR_LEN 32 /* Largest hardware address length */

/*
* Compute the worst case header length according to the protocols
diff -Naur linux-2.5.47/include/linux/rtnetlink.h linux-2.5.47-max-addr/include/linux/rtnetlink.h
--- linux-2.5.47/include/linux/rtnetlink.h Sun Nov 10 19:28:29 2002
+++ linux-2.5.47-max-addr/include/linux/rtnetlink.h Tue Dec 31 14:38:13 2002
@@ -17,6 +17,7 @@
#define RTM_NEWLINK (RTM_BASE+0)
#define RTM_DELLINK (RTM_BASE+1)
#define RTM_GETLINK (RTM_BASE+2)
+#define RTM_SETLINK (RTM_BASE+3)

#define RTM_NEWADDR (RTM_BASE+4)
#define RTM_DELADDR (RTM_BASE+5)
diff -Naur linux-2.5.47/net/core/dev.c linux-2.5.47-max-addr/net/core/dev.c
--- linux-2.5.47/net/core/dev.c Sun Nov 10 19:28:16 2002
+++ linux-2.5.47-max-addr/net/core/dev.c Mon Dec 30 12:06:06 2002
@@ -2062,7 +2062,7 @@

case SIOCGIFHWADDR:
memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
- MAX_ADDR_LEN);
+ min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
ifr->ifr_hwaddr.sa_family = dev->type;
return 0;

@@ -2083,7 +2083,7 @@
if (ifr->ifr_hwaddr.sa_family != dev->type)
return -EINVAL;
memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
- MAX_ADDR_LEN);
+ min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
notifier_call_chain(&netdev_chain,
NETDEV_CHANGEADDR, dev);
return 0;
diff -Naur linux-2.5.47/net/core/rtnetlink.c linux-2.5.47-max-addr/net/core/rtnetlink.c
--- linux-2.5.47/net/core/rtnetlink.c Sun Nov 10 19:28:33 2002
+++ linux-2.5.47-max-addr/net/core/rtnetlink.c Tue Dec 31 14:38:50 2002
@@ -220,6 +220,40 @@
return skb->len;
}

+static int do_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) {
+ struct ifinfomsg *ifm = NLMSG_DATA(nlh);
+ struct rtattr **ida = arg;
+ struct net_device *dev;
+ int err;
+
+ dev = dev_get_by_index(ifm->ifi_index);
+ if (!dev) {
+ return -ENODEV;
+ }
+
+ err = -EINVAL;
+
+ if (ida[IFLA_ADDRESS - 1]) {
+ if (ida[IFLA_ADDRESS - 1]->rta_len != RTA_LENGTH(dev->addr_len)) {
+ goto out;
+ }
+ memcpy(dev->dev_addr, RTA_DATA(ida[IFLA_ADDRESS - 1]), dev->addr_len);
+ }
+
+ if (ida[IFLA_BROADCAST - 1]) {
+ if (ida[IFLA_BROADCAST - 1]->rta_len != RTA_LENGTH(dev->addr_len)) {
+ goto out;
+ }
+ memcpy(dev->broadcast, RTA_DATA(ida[IFLA_BROADCAST - 1]), dev->addr_len);
+ }
+
+ err = 0;
+
+out:
+ dev_put(dev);
+ return err;
+}
+
int rtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx;
@@ -457,32 +491,14 @@

static struct rtnetlink_link link_rtnetlink_table[RTM_MAX-RTM_BASE+1] =
{
- { NULL, NULL, },
- { NULL, NULL, },
- { NULL, rtnetlink_dump_ifinfo, },
- { NULL, NULL, },
-
- { NULL, NULL, },
- { NULL, NULL, },
- { NULL, rtnetlink_dump_all, },
- { NULL, NULL, },
-
- { NULL, NULL, },
- { NULL, NULL, },
- { NULL, rtnetlink_dump_all, },
- { NULL, NULL, },
-
- { neigh_add, NULL, },
- { neigh_delete, NULL, },
- { NULL, neigh_dump_info, },
- { NULL, NULL, },
-
- { NULL, NULL, },
- { NULL, NULL, },
- { NULL, NULL, },
- { NULL, NULL, },
+ [RTM_GETLINK - RTM_BASE] = { .dumpit = rtnetlink_dump_ifinfo },
+ [RTM_SETLINK - RTM_BASE] = { .doit = do_setlink },
+ [RTM_GETADDR - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
+ [RTM_GETROUTE - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
+ [RTM_NEWNEIGH - RTM_BASE] = { .doit = neigh_add },
+ [RTM_DELNEIGH - RTM_BASE] = { .doit = neigh_delete },
+ [RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info }
};
-

static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
{
-
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