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Commit 8a27f7c9 authored by Joe Perches's avatar Joe Perches Committed by David S. Miller
Browse files

lib/vsprintf.c: Add "%pI6c" - print pointer as compressed ipv6 address

parent 9a7030b7
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+152 −47
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ioport.h>
#include <net/addrconf.h>

#include <asm/page.h>		/* for PAGE_SIZE */
#include <asm/div64.h>
@@ -630,60 +631,156 @@ static char *resource_string(char *buf, char *end, struct resource *res,
}

static char *mac_address_string(char *buf, char *end, u8 *addr,
				struct printf_spec spec)
				struct printf_spec spec, const char *fmt)
{
	char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */
	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
	char *p = mac_addr;
	int i;

	for (i = 0; i < 6; i++) {
		p = pack_hex_byte(p, addr[i]);
		if (!(spec.flags & SPECIAL) && i != 5)
		if (fmt[0] == 'M' && i != 5)
			*p++ = ':';
	}
	*p = '\0';
	spec.flags &= ~SPECIAL;

	return string(buf, end, mac_addr, spec);
}

static char *ip6_addr_string(char *buf, char *end, u8 *addr,
				struct printf_spec spec)
static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
{
	int i;

	for (i = 0; i < 4; i++) {
		char temp[3];	/* hold each IP quad in reverse order */
		int digits = put_dec_trunc(temp, addr[i]) - temp;
		if (leading_zeros) {
			if (digits < 3)
				*p++ = '0';
			if (digits < 2)
				*p++ = '0';
		}
		/* reverse the digits in the quad */
		while (digits--)
			*p++ = temp[digits];
		if (i < 3)
			*p++ = '.';
	}

	*p = '\0';
	return p;
}

static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
{
	char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */
	char *p = ip6_addr;
	int i;
	int j;
	int range;
	unsigned char zerolength[8];
	int longest = 1;
	int colonpos = -1;
	u16 word;
	u8 hi;
	u8 lo;
	bool needcolon = false;
	bool useIPv4 = ipv6_addr_v4mapped(addr) || ipv6_addr_is_isatap(addr);

	memset(zerolength, 0, sizeof(zerolength));

	if (useIPv4)
		range = 6;
	else
		range = 8;

	/* find position of longest 0 run */
	for (i = 0; i < range; i++) {
		for (j = i; j < range; j++) {
			if (addr->s6_addr16[j] != 0)
				break;
			zerolength[i]++;
		}
	}
	for (i = 0; i < range; i++) {
		if (zerolength[i] > longest) {
			longest = zerolength[i];
			colonpos = i;
		}
	}

	/* emit address */
	for (i = 0; i < range; i++) {
		if (i == colonpos) {
			if (needcolon || i == 0)
				*p++ = ':';
			*p++ = ':';
			needcolon = false;
			i += longest - 1;
			continue;
		}
		if (needcolon) {
			*p++ = ':';
			needcolon = false;
		}
		/* hex u16 without leading 0s */
		word = ntohs(addr->s6_addr16[i]);
		hi = word >> 8;
		lo = word & 0xff;
		if (hi) {
			if (hi > 0x0f)
				p = pack_hex_byte(p, hi);
			else
				*p++ = hex_asc_lo(hi);
		}
		if (hi || lo > 0x0f)
			p = pack_hex_byte(p, lo);
		else
			*p++ = hex_asc_lo(lo);
		needcolon = true;
	}

	if (useIPv4) {
		if (needcolon)
			*p++ = ':';
		p = ip4_string(p, &addr->s6_addr[12], false);
	}

	*p = '\0';
	return p;
}

static char *ip6_string(char *p, const struct in6_addr *addr, const char *fmt)
{
	int i;
	for (i = 0; i < 8; i++) {
		p = pack_hex_byte(p, addr[2 * i]);
		p = pack_hex_byte(p, addr[2 * i + 1]);
		if (!(spec.flags & SPECIAL) && i != 7)
		p = pack_hex_byte(p, addr->s6_addr[2 * i]);
		p = pack_hex_byte(p, addr->s6_addr[2 * i + 1]);
		if (fmt[0] == 'I' && i != 7)
			*p++ = ':';
	}

	*p = '\0';
	spec.flags &= ~SPECIAL;
	return p;
}

static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
			     struct printf_spec spec, const char *fmt)
{
	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];

	if (fmt[0] == 'I' && fmt[2] == 'c')
		ip6_compressed_string(ip6_addr, (const struct in6_addr *)addr);
	else
		ip6_string(ip6_addr, (const struct in6_addr *)addr, fmt);

	return string(buf, end, ip6_addr, spec);
}

static char *ip4_addr_string(char *buf, char *end, u8 *addr,
				struct printf_spec spec)
static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
			     struct printf_spec spec, const char *fmt)
{
	char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */
	char temp[3];	/* hold each IP quad in reverse order */
	char *p = ip4_addr;
	int i, digits;
	char ip4_addr[sizeof("255.255.255.255")];

	for (i = 0; i < 4; i++) {
		digits = put_dec_trunc(temp, addr[i]) - temp;
		/* reverse the digits in the quad */
		while (digits--)
			*p++ = temp[digits];
		if (i != 3)
			*p++ = '.';
	}
	*p = '\0';
	spec.flags &= ~SPECIAL;
	ip4_string(ip4_addr, addr, fmt[0] == 'i');

	return string(buf, end, ip4_addr, spec);
}
@@ -702,11 +799,15 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr,
 *       addresses (not the name nor the flags)
 * - 'M' For a 6-byte MAC address, it prints the address in the
 *       usual colon-separated hex notation
 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
 *       decimal for v4 and colon separated network-order 16 bit hex for v6)
 * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
 *       currently the same
 *
 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
 *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
 *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
 *       IPv6 omits the colons (01020304...0f)
 *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
 * - 'I6c' for IPv6 addresses printed as specified by
 *       http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
 * function pointers are really function descriptors, which contain a
 * pointer to the real address.
@@ -726,20 +827,24 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
		return symbol_string(buf, end, ptr, spec, *fmt);
	case 'R':
		return resource_string(buf, end, ptr, spec);
	case 'm':
		spec.flags |= SPECIAL;
		/* Fallthrough */
	case 'M':
		return mac_address_string(buf, end, ptr, spec);
	case 'i':
		spec.flags |= SPECIAL;
		/* Fallthrough */
	case 'I':
		if (fmt[1] == '6')
			return ip6_addr_string(buf, end, ptr, spec);
		if (fmt[1] == '4')
			return ip4_addr_string(buf, end, ptr, spec);
		spec.flags &= ~SPECIAL;
	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
	case 'm':			/* Contiguous: 000102030405 */
		return mac_address_string(buf, end, ptr, spec, fmt);
	case 'I':			/* Formatted IP supported
					 * 4:	1.2.3.4
					 * 6:	0001:0203:...:0708
					 * 6c:	1::708 or 1::1.2.3.4
					 */
	case 'i':			/* Contiguous:
					 * 4:	001.002.003.004
					 * 6:   000102...0f
					 */
		switch (fmt[1]) {
		case '6':
			return ip6_addr_string(buf, end, ptr, spec, fmt);
		case '4':
			return ip4_addr_string(buf, end, ptr, spec, fmt);
		}
		break;
	}
	spec.flags |= SMALL;