Add support for "human friendly" IPv6 address representations as specified in http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
This code has been adapted from Linux kernel with minimal modification.
Signed-off-by: Chris Packham judge.packham@gmail.com ---
Changes in v2: None
include/net6.h | 13 +++++ lib/vsprintf.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 144 insertions(+), 23 deletions(-)
diff --git a/include/net6.h b/include/net6.h index b622951..1b82c25 100644 --- a/include/net6.h +++ b/include/net6.h @@ -45,4 +45,17 @@ struct ip6_hdr { struct in6_addr daddr; };
+/* ::ffff:0:0/96 is reserved for v4 mapped addresses */ +static inline int ipv6_addr_v4mapped(const struct in6_addr *a) +{ + return (a->s6_addr32[0] | a->s6_addr32[1] | + (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0; +} + +/* Intra-Site Automatic Tunnel Addressing Protocol Address */ +static inline int ipv6_addr_is_isatap(const struct in6_addr *a) +{ + return (a->s6_addr32[2] | htonl(0x02000000)) == htonl(0x02005EFE); +} + #endif /* __NET6_H__ */ diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 4c82837..2baac47 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -23,6 +23,7 @@ #endif
#include <div64.h> +#include <net6.h> #define noinline __attribute__((noinline))
unsigned long simple_strtoul(const char *cp, char **endp, @@ -304,6 +305,7 @@ static noinline char *put_dec(char *buf, uint64_t num) #define LEFT 16 /* left justified */ #define SMALL 32 /* Must be 32 == 0x20 */ #define SPECIAL 64 /* 0x */ +#define COMPRESSED 128 /* use compressed format */
#ifdef CONFIG_SYS_VSNPRINTF /* @@ -469,12 +471,121 @@ static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width, flags & ~SPECIAL); }
-static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, +static char *ip4_string(char *p, u8 *addr) +{ + char temp[3]; /* hold each IP quad in reverse order */ + int i, digits; + + 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'; + + return p; +} + +static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, int precision, int flags) { - /* (8 * 4 hex digits), 7 colons and trailing zero */ - char ip6_addr[8 * 5]; - char *p = ip6_addr; + char ip4_addr[sizeof("255.255.255.255")]; + + ip4_string(ip4_addr, addr); + + return string(buf, end, ip4_addr, field_width, precision, + flags & ~SPECIAL); +} +#endif + +#ifdef CONFIG_NET6 +static char *ip6_compressed_string(char *p, u8 *addr) +{ + int i, j, range; + unsigned char zerolength[8]; + int longest = 1; + int colonpos = -1; + u16 word; + u8 hi, lo; + int needcolon = 0; + int useIPv4; + struct in6_addr in6; + + memcpy(&in6, addr, sizeof(struct in6_addr)); + + useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); + + 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 (in6.s6_addr16[j] != 0) + break; + zerolength[i]++; + } + } + for (i = 0; i < range; i++) { + if (zerolength[i] > longest) { + longest = zerolength[i]; + colonpos = i; + } + } + if (longest == 1) /* don't compress a single 0 */ + colonpos = -1; + + /* emit address */ + for (i = 0; i < range; i++) { + if (i == colonpos) { + if (needcolon || i == 0) + *p++ = ':'; + *p++ = ':'; + needcolon = 0; + i += longest - 1; + continue; + } + if (needcolon) { + *p++ = ':'; + needcolon = 0; + } + /* hex u16 without leading 0s */ + word = ntohs(in6.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); + p = pack_hex_byte(p, lo); + } else if (lo > 0x0f) { + p = pack_hex_byte(p, lo); + } else { + *p++ = hex_asc_lo(lo); + } + needcolon = 1; + } + + if (useIPv4) { + if (needcolon) + *p++ = ':'; + p = ip4_string(p, &in6.s6_addr[12]); + } + *p = '\0'; + + return p; +} + +static char *ip6_string(char *p, u8 *addr, int flags) +{ int i;
for (i = 0; i < 8; i++) { @@ -485,30 +596,20 @@ static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, } *p = '\0';
- return string(buf, end, ip6_addr, field_width, precision, - flags & ~SPECIAL); + return p; }
-static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, +static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, int precision, int flags) { - /* (4 * 3 decimal digits), 3 dots and trailing zero */ - char ip4_addr[4 * 4]; - char temp[3]; /* hold each IP quad in reverse order */ - char *p = ip4_addr; - int i, digits; + char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx: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'; + if (flags & COMPRESSED) + ip6_compressed_string(ip6_addr, addr); + else + ip6_string(ip6_addr, addr, flags);
- return string(buf, end, ip4_addr, field_width, precision, + return string(buf, end, ip6_addr, field_width, precision, flags & ~SPECIAL); } #endif @@ -526,6 +627,8 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, * 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 + * - 'I6c' for IPv6 addresses printed as specified by + * http://tools.ietf.org/html/rfc5952 * * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 * function pointers are really function descriptors, which contain a @@ -569,9 +672,14 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr, flags |= SPECIAL; /* Fallthrough */ case 'I': - if (fmt[1] == '6') +#ifdef CONFIG_NET6 + if (fmt[1] == '6') { + if (fmt[2] == 'c') + flags |= COMPRESSED; return ip6_addr_string(buf, end, ptr, field_width, precision, flags); + } +#endif if (fmt[1] == '4') return ip4_addr_string(buf, end, ptr, field_width, precision, flags);