From bdad2fefb206d9727d4a3254f7883b8455452d89 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 4 Jun 2014 02:24:38 -0400 Subject: add support for ipv6 scope_id to getaddrinfo and getnameinfo for all address types, a scope_id specified as a decimal value is accepted. for addresses with link-local scope, a string containing the interface name is also accepted. some changes are made to error handling to avoid unwanted fallbacks in the case where the scope_id is invalid: if an earlier name lookup backend fails with an error rather than simply "0 results", this failure now suppresses any later attempts with other backends. in getnameinfo, a light "itoa" type function is added for generating decimal scope_id results, and decimal port strings for services are also generated using this function now so as not to pull in the dependency on snprintf. in netdb.h, a definition for the NI_NUMERICSCOPE flag is added. this is required by POSIX (it was previously missing) and needed to allow callers to suppress interface-name lookups. --- src/network/getnameinfo.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) (limited to 'src/network/getnameinfo.c') diff --git a/src/network/getnameinfo.c b/src/network/getnameinfo.c index dfcf6eda..6962ed1a 100644 --- a/src/network/getnameinfo.c +++ b/src/network/getnameinfo.c @@ -5,6 +5,7 @@ #include #include #include +#include int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *); int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int); @@ -14,6 +15,16 @@ int __res_send(const unsigned char *, int, unsigned char *, int); #define PTR_MAX (64 + sizeof ".in-addr.arpa") #define RR_PTR 12 +static char *itoa(char *p, unsigned x) { + p += 3*sizeof(int); + *--p = 0; + do { + *--p = '0' + x % 10; + x /= 10; + } while (x); + return p; +} + static void mkptr4(char *s, const unsigned char *ip) { sprintf(s, "%d.%d.%d.%d.in-addr.arpa", @@ -48,9 +59,10 @@ int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl, int flags) { char ptr[PTR_MAX]; - char buf[256]; + char buf[256], num[3*sizeof(int)+1]; int af = sa->sa_family; unsigned char *a; + unsigned x; switch (af) { case AF_INET: @@ -84,16 +96,28 @@ int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl, if (!*buf) { if (flags & NI_NAMEREQD) return EAI_NONAME; inet_ntop(af, a, buf, sizeof buf); + if (af == AF_INET6 && + (x = ((struct sockaddr_in6 *)sa)->sin6_scope_id)) { + char *p = 0, tmp[IF_NAMESIZE+1]; + if (!(flags & NI_NUMERICSCOPE) && + (IN6_IS_ADDR_LINKLOCAL(a) || + IN6_IS_ADDR_MC_LINKLOCAL(a))) + p = if_indextoname(x, tmp+1); + if (!p) + p = itoa(num, x); + *--p = '%'; + strcat(buf, p); + } } if (strlen(buf) >= nodelen) return EAI_OVERFLOW; strcpy(node, buf); } if (serv && servlen) { - if (snprintf(buf, sizeof buf, "%d", - ntohs(((struct sockaddr_in *)sa)->sin_port))>=servlen) + char *p = itoa(num, ntohs(((struct sockaddr_in *)sa)->sin_port)); + if (strlen(p) >= servlen) return EAI_OVERFLOW; - strcpy(serv, buf); + strcpy(serv, p); } return 0; -- cgit v1.2.1