From f18a1dadd4508e74c0aed37d8ac92046c30fbfe7 Mon Sep 17 00:00:00 2001 From: Simo Sorce Date: Tue, 2 Apr 2013 13:18:09 -0400 Subject: Avoid reverse resolution for server name A NFS client should be able to work properly even if the DNS Reverse record for the server is not set. There is no excuse to forcefully prevent that from working when it can. This patch adds a new pair of options (-z/-Z) that allow to turn on/off DNS reverse resolution for determining the server name to use with GSSAPI. To avoid breaking current behavior the option defaults to off by default, ideally we will turn this on by default after a transition period. Signed-off-by: Simo Sorce --- utils/gssd/gssd_proc.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'utils/gssd/gssd_proc.c') diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c index d6f07e6..b123978 100644 --- a/utils/gssd/gssd_proc.c +++ b/utils/gssd/gssd_proc.c @@ -67,6 +67,7 @@ #include #include #include +#include #include "gssd.h" #include "err_util.h" @@ -107,6 +108,8 @@ struct pollfd * pollarray; unsigned long pollsize; /* the size of pollaray (in pollfd's) */ +int avoid_ptr = 0; + /* * convert a presentation address string to a sockaddr_storage struct. Returns * true on success or false on failure. @@ -165,12 +168,26 @@ addrstr_to_sockaddr(struct sockaddr *sa, const char *node, const char *port) * convert a sockaddr to a hostname */ static char * -sockaddr_to_hostname(const struct sockaddr *sa, const char *addr) +get_servername(const char *name, const struct sockaddr *sa, const char *addr) { socklen_t addrlen; int err; char *hostname; char hbuf[NI_MAXHOST]; + unsigned char buf[sizeof(struct in6_addr)]; + int do_ptr_lookup = 0; + + if (avoid_ptr) { + /* try to determine if this is a name, or an IP address. + * If it is an IP fallback to a PTR lookup */ + if (strchr(name, '.') && inet_pton(AF_INET, name, buf) == 1) + do_ptr_lookup = 1; /* IPv4 */ + else if (strchr(name, ':') && inet_pton(AF_INET6, name, buf) == 1) + do_ptr_lookup = 1; /* or IPv6 */ + if (!do_ptr_lookup) { + return strdup(name); + } + } switch (sa->sa_family) { case AF_INET: @@ -208,7 +225,7 @@ read_service_info(char *info_file_name, char **servicename, char **servername, struct sockaddr *addr) { #define INFOBUFLEN 256 char buf[INFOBUFLEN + 1]; - static char dummy[128]; + static char server[128]; int nbytes; static char service[128]; static char address[128]; @@ -236,7 +253,7 @@ read_service_info(char *info_file_name, char **servicename, char **servername, "service: %127s %15s version %15s\n" "address: %127s\n" "protocol: %15s\n", - dummy, + server, service, program, version, address, protoname); @@ -258,7 +275,7 @@ read_service_info(char *info_file_name, char **servicename, char **servername, if (!addrstr_to_sockaddr(addr, address, port)) goto fail; - *servername = sockaddr_to_hostname(addr, address); + *servername = get_servername(server, addr, address); if (*servername == NULL) goto fail; -- cgit