From bdad2fefb206d9727d4a3254f7883b8455452d89 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 4 Jun 2014 02:24:38 -0400 Subject: [PATCH] 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. --- include/netdb.h | 2 +- src/network/getaddrinfo.c | 1 + src/network/getnameinfo.c | 32 ++++++++++++++++++++++++++++---- src/network/lookup_name.c | 31 +++++++++++++++++++++++++++---- 4 files changed, 57 insertions(+), 9 deletions(-) diff --git a/include/netdb.h b/include/netdb.h index dfc70e2b..703a4b26 100644 --- a/include/netdb.h +++ b/include/netdb.h @@ -41,7 +41,7 @@ struct addrinfo #define NI_NOFQDN 0x04 #define NI_NAMEREQD 0x08 #define NI_DGRAM 0x10 -/*#define NI_NUMERICSCOPE */ +#define NI_NUMERICSCOPE 0x100 #define EAI_BADFLAGS -1 #define EAI_NONAME -2 diff --git a/src/network/getaddrinfo.c b/src/network/getaddrinfo.c index 70b6cfda..d9913445 100644 --- a/src/network/getaddrinfo.c +++ b/src/network/getaddrinfo.c @@ -105,6 +105,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru case AF_INET6: out[k].sa.sin6.sin6_family = AF_INET6; out[k].sa.sin6.sin6_port = htons(ports[j].port); + out[k].sa.sin6.sin6_scope_id = addrs[i].scopeid; memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16); break; } 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; diff --git a/src/network/lookup_name.c b/src/network/lookup_name.c index 02920930..492e932c 100644 --- a/src/network/lookup_name.c +++ b/src/network/lookup_name.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include #include @@ -47,9 +48,31 @@ static int name_from_numeric(struct address buf[static 1], const char *name, int buf[0].family = AF_INET; return 1; } - if (family != AF_INET && inet_pton(AF_INET6, name, &a6)>0) { + if (family != AF_INET) { + char tmp[64]; + char *p = strchr(name, '%'), *z; + unsigned long long scopeid; + if (p && p-name < 64) { + memcpy(tmp, name, p-name); + tmp[p-name] = 0; + name = tmp; + } + if (inet_pton(AF_INET6, name, &a6)<=0) return 0; memcpy(&buf[0].addr, &a6, sizeof a6); buf[0].family = AF_INET6; + if (p) { + if (isdigit(*++p)) scopeid = strtoull(p, &z, 10); + else z = p-1; + if (*z) { + if (!IN6_IS_ADDR_LINKLOCAL(&a6) && + !IN6_IS_ADDR_MC_LINKLOCAL(&a6)) + return EAI_NONAME; + scopeid = if_nametoindex(p); + if (!scopeid) return EAI_NONAME; + } + if (scopeid > UINT_MAX) return EAI_NONAME; + buf[0].scopeid = scopeid; + } return 1; } return 0; @@ -179,10 +202,10 @@ int __lookup_name(struct address buf[static MAXADDRS], char canon[static 256], c /* Try each backend until there's at least one result. */ cnt = name_from_null(buf, name, family, flags); - if (cnt<=0) cnt = name_from_numeric(buf, name, family); - if (cnt<=0 && !(flags & AI_NUMERICHOST)) { + if (!cnt) cnt = name_from_numeric(buf, name, family); + if (!cnt && !(flags & AI_NUMERICHOST)) { cnt = name_from_hosts(buf, canon, name, family); - if (cnt<=0) cnt = name_from_dns(buf, canon, name, family); + if (!cnt) cnt = name_from_dns(buf, canon, name, family); } if (cnt<=0) return cnt ? cnt : EAI_NONAME; -- 2.25.1