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lib/vsprintf.c: Add "%pI6c" - print pointer as compressed ipv6 address
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Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Jens Rosenboom <jens@mcbone.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Joe Perches authored and David S. Miller committed Aug 29, 2009
1 parent 9a7030b commit 8a27f7c
Showing 1 changed file with 152 additions and 47 deletions.
199 changes: 152 additions & 47 deletions lib/vsprintf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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);
}
Expand All @@ -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.
Expand All @@ -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;
Expand Down

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