Commit 4940fc88 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by David S. Miller
Browse files

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: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 99f823f9

drivers/net/netconsole.c

+4 −16
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -1420,11 +1420,6 @@ static ssize_t pktgen_if_write(struct file *file, 
		return count;

	}

	if (!strcmp(name, "dst_mac")) {

		char *v = valstr;

		unsigned char old_dmac[ETH_ALEN];

		unsigned char *m = pkt_dev->dst_mac;

		memcpy(old_dmac, pkt_dev->dst_mac, ETH_ALEN);



		len = strn_len(&user_buffer[i], sizeof(valstr) - 1);

		if (len < 0)

			return len;
@@ -1432,35 +1427,16 @@ static ssize_t pktgen_if_write(struct file *file, 
		memset(valstr, 0, sizeof(valstr));

		if (copy_from_user(valstr, &user_buffer[i], len))

			return -EFAULT;

		i += len;



		for (*m = 0; *v && m < pkt_dev->dst_mac + 6; v++) {

			int value;



			value = hex_to_bin(*v);

			if (value >= 0)

				*m = *m * 16 + value;



			if (*v == ':') {

				m++;

				*m = 0;

			}

		}



		if (!mac_pton(valstr, pkt_dev->dst_mac))

			return -EINVAL;

		/* Set up Dest MAC */

		if (compare_ether_addr(old_dmac, pkt_dev->dst_mac))

			memcpy(&(pkt_dev->hh[0]), pkt_dev->dst_mac, ETH_ALEN);

		memcpy(&pkt_dev->hh[0], pkt_dev->dst_mac, ETH_ALEN);



		sprintf(pg_result, "OK: dstmac");

		sprintf(pg_result, "OK: dstmac %pM", pkt_dev->dst_mac);

		return count;

	}

	if (!strcmp(name, "src_mac")) {

		char *v = valstr;

		unsigned char old_smac[ETH_ALEN];

		unsigned char *m = pkt_dev->src_mac;



		memcpy(old_smac, pkt_dev->src_mac, ETH_ALEN);



		len = strn_len(&user_buffer[i], sizeof(valstr) - 1);

		if (len < 0)

			return len;
@@ -1468,26 +1444,13 @@ static ssize_t pktgen_if_write(struct file *file, 
		memset(valstr, 0, sizeof(valstr));

		if (copy_from_user(valstr, &user_buffer[i], len))

			return -EFAULT;

		i += len;



		for (*m = 0; *v && m < pkt_dev->src_mac + 6; v++) {

			int value;



			value = hex_to_bin(*v);

			if (value >= 0)

				*m = *m * 16 + value;



			if (*v == ':') {

				m++;

				*m = 0;

			}

		}



		if (!mac_pton(valstr, pkt_dev->src_mac))

			return -EINVAL;

		/* Set up Src MAC */

		if (compare_ether_addr(old_smac, pkt_dev->src_mac))

			memcpy(&(pkt_dev->hh[6]), pkt_dev->src_mac, ETH_ALEN);

		memcpy(&pkt_dev->hh[6], pkt_dev->src_mac, ETH_ALEN);



		sprintf(pg_result, "OK: srcmac");

		sprintf(pg_result, "OK: srcmac %pM", pkt_dev->src_mac);

		return count;

	}

net/core/utils.c

+24 −0
Original line number Diff line number Diff line
@@ -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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE