resolv: Deprecate legacy interfaces in libresolv

Debugging interfaces: p_*, fp_*, and sym_* could conceivably be
used to produce debug out, but these functions have not been
updated to parse more resource records, so they are not very useful
today.  Likewise for ns_sprintrr and ns_sprintrrf.  ns_format_ttl and
ns_parse_ttl are related to these.

Internal implementation details: res_isourserver is probably only
useful in the implementation of a stub resolver, and so is
res_nameinquery.

Unclear semantics and bad performance: ns_samedomain, ns_subdomain,
ns_makecanon, ns_samename do textual converions & copies instead of
checking equivalence of the wire format.

inet_neta cannot handle IPv6 addresses.

res_hostalias has been superseded by getaddrinfo with AI_CANONNAME.
hostalias is not thread-safe.

Some functions have int as size arguments instead of size_t, so they
do not follow current coding practices.  However, dn_expand and
b64_ntop are somewhat widely used (to name just two examples), so
deprecating them seems problematic.

Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
This commit is contained in:
Florian Weimer 2021-07-19 07:55:27 +02:00
parent 191e406826
commit 248dbed118
4 changed files with 95 additions and 41 deletions

14
NEWS
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@ -93,6 +93,20 @@ Deprecated and removed features, and other changes affecting compatibility:
* The function pthread_yield has been deprecated; programs should use
the equivalent standard function sched_yield instead.
* The function inet_neta declared in <arpa/inet.h> has been deprecated.
* Various rarely-used functions declared in <resolv.h> and
<arpa/nameser.h> have been deprecated. Applications are encouraged to
use dedicated DNS processing libraries if applicable. For <resolv.h>,
this affects the functions dn_count_labels, fp_nquery, fp_query,
fp_resstat, hostalias, loc_aton, loc_ntoa, p_cdname, p_cdnname,
p_class, p_fqname, p_fqnname, p_option, p_query, p_rcode, p_time,
p_type, putlong, putshort, res_hostalias, res_isourserver,
res_nameinquery, res_queriesmatch, res_randomid, sym_ntop, sym_ntos,
sym_ston. For <arpa/nameser.h>, the functions ns_datetosecs,
ns_format_ttl, ns_makecanon, ns_parse_ttl, ns_samedomain, ns_samename,
ns_sprintrr, ns_sprintrrf, ns_subdomain have been deprecated.
* The pthread cancellation handler is now installed with SA_RESTART and
pthread_cancel will always send the internal SIGCANCEL on a cancellation
request. It should not be visible to application since the cancellation

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@ -74,7 +74,8 @@ extern int inet_aton (const char *__cp, struct in_addr *__inp) __THROW;
/* Format a network number NET into presentation format and place result
in buffer starting at BUF with length of LEN bytes. */
extern char *inet_neta (in_addr_t __net, char *__buf, size_t __len) __THROW;
extern char *inet_neta (in_addr_t __net, char *__buf, size_t __len) __THROW
__attribute_deprecated_msg__ ("Use inet_ntop instead");
/* Convert network number for interface type AF in buffer starting at
CP to presentation format. The result will specifiy BITS bits of

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@ -52,6 +52,12 @@
#include <sys/types.h>
#include <stdint.h>
#ifdef _LIBC
# define __NAMESER_DEPRECATED
#else
# define __NAMESER_DEPRECATED __attribute_deprecated__
#endif
/*
* Define constants based on RFC 883, RFC 1034, RFC 1035
*/
@ -401,14 +407,18 @@ int ns_skiprr (const unsigned char *, const unsigned char *,
int ns_parserr (ns_msg *, ns_sect, int, ns_rr *) __THROW;
int ns_sprintrr (const ns_msg *, const ns_rr *,
const char *, const char *, char *, size_t)
__THROW;
__THROW __NAMESER_DEPRECATED;
int ns_sprintrrf (const unsigned char *, size_t, const char *,
ns_class, ns_type, unsigned long,
const unsigned char *, size_t, const char *,
const char *, char *, size_t) __THROW;
int ns_format_ttl (unsigned long, char *, size_t) __THROW;
int ns_parse_ttl (const char *, unsigned long *) __THROW;
uint32_t ns_datetosecs (const char *, int *) __THROW;
const char *, char *, size_t)
__THROW __NAMESER_DEPRECATED;
int ns_format_ttl (unsigned long, char *, size_t)
__THROW __NAMESER_DEPRECATED;
int ns_parse_ttl (const char *, unsigned long *)
__THROW __NAMESER_DEPRECATED;
uint32_t ns_datetosecs (const char *, int *)
__THROW __NAMESER_DEPRECATED;
int ns_name_ntol (const unsigned char *, unsigned char *, size_t)
__THROW;
int ns_name_ntop (const unsigned char *, char *, size_t) __THROW;
@ -431,10 +441,15 @@ int ns_name_skip (const unsigned char **, const unsigned char *)
void ns_name_rollback (const unsigned char *,
const unsigned char **,
const unsigned char **) __THROW;
int ns_samedomain (const char *, const char *) __THROW;
int ns_subdomain (const char *, const char *) __THROW;
int ns_makecanon (const char *, char *, size_t) __THROW;
int ns_samename (const char *, const char *) __THROW;
int ns_samedomain (const char *, const char *) __THROW
__NAMESER_DEPRECATED;
int ns_subdomain (const char *, const char *) __THROW
__NAMESER_DEPRECATED;
int ns_makecanon (const char *, char *, size_t) __THROW
__NAMESER_DEPRECATED;
int ns_samename (const char *, const char *) __THROW
__NAMESER_DEPRECATED;
__END_DECLS
#include <arpa/nameser_compat.h>

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@ -174,14 +174,27 @@ __END_DECLS
#define res_search __res_search
#define res_send __res_send
#ifdef _LIBC
# define __RESOLV_DEPRECATED
# define __RESOLV_DEPRECATED_MSG(msg)
#else
# define __RESOLV_DEPRECATED __attribute_deprecated__
# define __RESOLV_DEPRECATED_MSG(msg) __attribute_deprecated_msg__ (msg)
#endif
__BEGIN_DECLS
void fp_nquery (const unsigned char *, int, FILE *) __THROW;
void fp_query (const unsigned char *, FILE *) __THROW;
const char * hostalias (const char *) __THROW;
void p_query (const unsigned char *) __THROW;
void fp_nquery (const unsigned char *, int, FILE *) __THROW
__RESOLV_DEPRECATED;
void fp_query (const unsigned char *, FILE *) __THROW
__RESOLV_DEPRECATED;
const char * hostalias (const char *) __THROW
__RESOLV_DEPRECATED_MSG ("use getaddrinfo instead");
void p_query (const unsigned char *) __THROW
__RESOLV_DEPRECATED;
void res_close (void) __THROW;
int res_init (void) __THROW;
int res_isourserver (const struct sockaddr_in *) __THROW;
int res_isourserver (const struct sockaddr_in *) __THROW
__RESOLV_DEPRECATED;
int res_mkquery (int, const char *, int, int,
const unsigned char *, int, const unsigned char *,
unsigned char *, int) __THROW;
@ -238,50 +251,61 @@ int res_hnok (const char *) __THROW;
int res_ownok (const char *) __THROW;
int res_mailok (const char *) __THROW;
int res_dnok (const char *) __THROW;
int sym_ston (const struct res_sym *, const char *, int *) __THROW;
const char * sym_ntos (const struct res_sym *, int, int *) __THROW;
const char * sym_ntop (const struct res_sym *, int, int *) __THROW;
int sym_ston (const struct res_sym *, const char *, int *) __THROW
__RESOLV_DEPRECATED;
const char * sym_ntos (const struct res_sym *, int, int *) __THROW
__RESOLV_DEPRECATED;
const char * sym_ntop (const struct res_sym *, int, int *) __THROW
__RESOLV_DEPRECATED;
int b64_ntop (const unsigned char *, size_t, char *, size_t)
__THROW;
__THROW;
int b64_pton (char const *, unsigned char *, size_t) __THROW;
int loc_aton (const char *__ascii, unsigned char *__binary) __THROW;
const char * loc_ntoa (const unsigned char *__binary, char *__ascii) __THROW;
int loc_aton (const char *__ascii, unsigned char *__binary) __THROW
__RESOLV_DEPRECATED;
const char * loc_ntoa (const unsigned char *__binary, char *__ascii) __THROW
__RESOLV_DEPRECATED;
int dn_skipname (const unsigned char *, const unsigned char *)
__THROW;
void putlong (uint32_t, unsigned char *) __THROW;
void putshort (uint16_t, unsigned char *) __THROW;
const char * p_class (int) __THROW;
const char * p_time (uint32_t) __THROW;
const char * p_type (int) __THROW;
const char * p_rcode (int) __THROW;
const unsigned char * p_cdnname (const unsigned char *,
const unsigned char *, int, FILE *) __THROW;
__THROW;
void putlong (uint32_t, unsigned char *) __THROW
__RESOLV_DEPRECATED_MSG ("use NS_PUT16 instead");
void putshort (uint16_t, unsigned char *) __THROW
__RESOLV_DEPRECATED_MSG ("use NS_PUT32 instead");
const char * p_class (int) __THROW __RESOLV_DEPRECATED;
const char * p_time (uint32_t) __THROW __RESOLV_DEPRECATED;
const char * p_type (int) __THROW __RESOLV_DEPRECATED;
const char * p_rcode (int) __THROW __RESOLV_DEPRECATED;
const unsigned char * p_cdnname (const unsigned char *, const unsigned char *,
int, FILE *) __THROW __RESOLV_DEPRECATED;
const unsigned char * p_cdname (const unsigned char *, const unsigned char *,
FILE *) __THROW;
FILE *) __THROW __RESOLV_DEPRECATED;
const unsigned char * p_fqnname (const unsigned char *__cp,
const unsigned char *__msg,
int, char *, int) __THROW;
const unsigned char * p_fqname (const unsigned char *,
const unsigned char *, FILE *) __THROW;
const char * p_option (unsigned long __option) __THROW;
int dn_count_labels (const char *) __THROW;
int, char *, int) __THROW __RESOLV_DEPRECATED;
const unsigned char * p_fqname (const unsigned char *, const unsigned char *,
FILE *) __THROW __RESOLV_DEPRECATED;
const char * p_option (unsigned long __option) __THROW __RESOLV_DEPRECATED;
int dn_count_labels (const char *) __THROW __RESOLV_DEPRECATED;
int dn_comp (const char *, unsigned char *, int, unsigned char **,
unsigned char **) __THROW;
int dn_expand (const unsigned char *, const unsigned char *,
const unsigned char *, char *, int) __THROW;
unsigned int res_randomid (void) __THROW;
unsigned int res_randomid (void) __THROW
__RESOLV_DEPRECATED_MSG ("use getentropy instead");
int res_nameinquery (const char *, int, int,
const unsigned char *,
const unsigned char *) __THROW;
const unsigned char *) __THROW
__RESOLV_DEPRECATED;
int res_queriesmatch (const unsigned char *,
const unsigned char *,
const unsigned char *,
const unsigned char *) __THROW;
const unsigned char *) __THROW
__RESOLV_DEPRECATED;
/* Things involving a resolver context. */
int res_ninit (res_state) __THROW;
void fp_resstat (const res_state, FILE *) __THROW;
void fp_resstat (const res_state, FILE *) __THROW
__RESOLV_DEPRECATED;
const char * res_hostalias (const res_state, const char *, char *, size_t)
__THROW;
__THROW __RESOLV_DEPRECATED_MSG ("use getaddrinfo instead");
int res_nquery (res_state, const char *, int, int,
unsigned char *, int) __THROW;
int res_nsearch (res_state, const char *, int, int,