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net: add mac_pton() for parsing MAC address

PATCH Applied Alexey Dobriyan 2 participants 2 messages May 8, 2011 – May 9, 2011

Subsystems (3)
Networking Network drivers Netconsole
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Alexey Dobriyan

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#0 lore raw

PATCH v2 1/1 net: add mac_pton() for parsing MAC address

mac_pton() parses MAC address in form XX:XX:XX:XX:XX:XX and only in that form.

mac_pton() doesn't dirty result until it's sure string representation is valid.

mac_pton() doesn't care about characters _after_ last octet, it's up to caller to deal with it.

mac_pton() diverges from 0/-E return value convention. Target usage:

	if (!mac_pton(str, whatever->mac))
		return -EINVAL;
	/* ->mac being u8 [ETH_ALEN] is filled at this point. */
	/* optionally check str[3 * ETH_ALEN - 1] for termination */

Use mac_pton() in pktgen and netconsole for start.

Signed-off-by Alexey Dobriyan <[email protected]>

---

 drivers/net/netconsole.c |   20 +++--------------
 include/linux/if_ether.h |    1 
 net/core/netpoll.c       |   26 -----------------------
 net/core/pktgen.c        |   53 +++++++----------------------------------------
 net/core/utils.c         |   24 +++++++++++++++++++++
 5 files changed, 38 insertions(+), 86 deletions(-)
drivers/net/netconsole.c +4 -16
@@ -429,8 +429,6 @@ static ssize_t store_remote_mac(struct netconsole_target *nt,
 				size_t count)
 {
 	u8 remote_mac[ETH_ALEN];
-	char *p = (char *) buf;
-	int i;
 
 	if (nt->enabled) {
 		printk(KERN_ERR "netconsole: target (%s) is enabled, "

@@ -439,23 +437,13 @@ static ssize_t store_remote_mac(struct netconsole_target *nt,
 		return -EINVAL;
 	}
 
-	for (i = 0; i < ETH_ALEN - 1; i++) {
-		remote_mac[i] = simple_strtoul(p, &p, 16);
-		if (*p != ':')
-			goto invalid;
-		p++;
-	}
-	remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
-	if (*p && (*p != '\n'))
-		goto invalid;
-
+	if (!mac_pton(buf, remote_mac))
+		return -EINVAL;
+	if (buf[3 * ETH_ALEN - 1] && buf[3 * ETH_ALEN - 1] != '\n')
+		return -EINVAL;
 	memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
 
 	return strnlen(buf, count);
-
-invalid:
-	printk(KERN_ERR "netconsole: invalid input\n");
-	return -EINVAL;
 }
 
 /*
include/linux/if_ether.h +1 -0
@@ -136,6 +136,7 @@ int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
 extern struct ctl_table ether_table[];
 #endif
 
+int mac_pton(const char *s, u8 *mac);
 extern ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len);
 
 #endif
net/core/netpoll.c +1 -25
@@ -698,32 +698,8 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 
 	if (*cur != 0) {
 		/* MAC address */
-		if ((delim = strchr(cur, ':')) == NULL)
+		if (!mac_pton(cur, np->remote_mac))
 			goto parse_failed;
-		*delim = 0;
-		np->remote_mac[0] = simple_strtol(cur, NULL, 16);
-		cur = delim + 1;
-		if ((delim = strchr(cur, ':')) == NULL)
-			goto parse_failed;
-		*delim = 0;
-		np->remote_mac[1] = simple_strtol(cur, NULL, 16);
-		cur = delim + 1;
-		if ((delim = strchr(cur, ':')) == NULL)
-			goto parse_failed;
-		*delim = 0;
-		np->remote_mac[2] = simple_strtol(cur, NULL, 16);
-		cur = delim + 1;
-		if ((delim = strchr(cur, ':')) == NULL)
-			goto parse_failed;
-		*delim = 0;
-		np->remote_mac[3] = simple_strtol(cur, NULL, 16);
-		cur = delim + 1;
-		if ((delim = strchr(cur, ':')) == NULL)
-			goto parse_failed;
-		*delim = 0;
-		np->remote_mac[4] = simple_strtol(cur, NULL, 16);
-		cur = delim + 1;
-		np->remote_mac[5] = simple_strtol(cur, NULL, 16);
 	}
 
 	netpoll_print_options(np);
net/core/pktgen.c +8 -45

80 lines not on this page · raw message

net/core/utils.c +24 -0
@@ -296,3 +296,27 @@ void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
 				csum_unfold(*sum)));
 }
 EXPORT_SYMBOL(inet_proto_csum_replace4);
+
+int mac_pton(const char *s, u8 *mac)
+{
+	int i;
+
+	/* XX:XX:XX:XX:XX:XX */
+	if (strlen(s) < 3 * ETH_ALEN - 1)
+		return 0;
+
+	/* Don't dirty result unless string is valid MAC. */
+	for (i = 0; i < ETH_ALEN; i++) {
+		if (!strchr("0123456789abcdefABCDEF", s[i * 3]))
+			return 0;
+		if (!strchr("0123456789abcdefABCDEF", s[i * 3 + 1]))
+			return 0;
+		if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
+			return 0;
+	}
+	for (i = 0; i < ETH_ALEN; i++) {
+		mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
+	}
+	return 1;
+}
+EXPORT_SYMBOL(mac_pton);
maintainer Applied
#1 lore raw

From: Alexey Dobriyan <[email protected]>
Date: Sun, 8 May 2011 12:00:07 +0300

Quoted 10 lines

mac_pton() parses MAC address in form XX:XX:XX:XX:XX:XX and only in that form.

mac_pton() doesn't dirty result until it's sure string representation is valid.

mac_pton() doesn't care about characters _after_ last octet, it's up to caller to deal with it.

mac_pton() diverges from 0/-E return value convention. Target usage:

Quoted 8 lines
	if (!mac_pton(str, whatever->mac))
		return -EINVAL;
	/* ->mac being u8 [ETH_ALEN] is filled at this point. */
	/* optionally check str[3 * ETH_ALEN - 1] for termination */

Use mac_pton() in pktgen and netconsole for start.

Signed-off-by Alexey Dobriyan <[email protected]>

Applied.