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dirmngr: Implement a getnameinfo wrapper.

* dirmngr/dns-stuff.h (DNS_NUMERICHOST): New.
(DNS_WITHBRACKET): New.
* dirmngr/dns-stuff.c (resolve_name_standard): Factor code out to...
(map_eai_to_gpg_error): new.
(resolve_addr_standard): New.
(resolve_dns_addr): New.

* dirmngr/ks-engine-hkp.c (is_ip_address): Move to ...
* dirmngr/dns-stuff.c (is_ip_address): here.  Add support for non
bracketed v6 addresses.

* dirmngr/t-dns-stuff.c: Remove header netdb.h.
(main): Add option --bracket.  Use resolve_dns_name instead of
getnameinfo.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2015-10-24 16:27:47 +02:00
parent 7f65e84ac0
commit 816505958a
No known key found for this signature in database
GPG key ID: E3FDFF218E45B72B
4 changed files with 221 additions and 60 deletions

View file

@ -54,6 +54,11 @@
#include "host2net.h"
#include "dns-stuff.h"
#if AF_UNSPEC != 0
# error AF_UNSPEC does not have the value 0
#endif
/* Not every installation has gotten around to supporting SRVs or
CERTs yet... */
#ifndef T_SRV
@ -96,6 +101,30 @@ free_dns_addrinfo (dns_addrinfo_t ai)
}
static gpg_error_t
map_eai_to_gpg_error (int ec)
{
gpg_error_t err;
switch (ec)
{
case EAI_AGAIN: err = gpg_error (GPG_ERR_EAGAIN); break;
case EAI_BADFLAGS: err = gpg_error (GPG_ERR_INV_FLAG); break;
case EAI_FAIL: err = gpg_error (GPG_ERR_SERVER_FAILED); break;
case EAI_MEMORY: err = gpg_error (GPG_ERR_ENOMEM); break;
case EAI_NODATA: err = gpg_error (GPG_ERR_NO_DATA); break;
case EAI_NONAME: err = gpg_error (GPG_ERR_NO_NAME); break;
case EAI_SERVICE: err = gpg_error (GPG_ERR_NOT_SUPPORTED); break;
case EAI_ADDRFAMILY:err = gpg_error (GPG_ERR_EADDRNOTAVAIL); break;
case EAI_FAMILY: err = gpg_error (GPG_ERR_EAFNOSUPPORT); break;
case EAI_SOCKTYPE: err = gpg_error (GPG_ERR_ESOCKTNOSUPPORT); break;
case EAI_SYSTEM: err = gpg_error_from_syserror (); break;
default: err = gpg_error (GPG_ERR_UNKNOWN_ERRNO); break;
}
return err;
}
/* Resolve a name using the standard system function. */
static gpg_error_t
resolve_name_standard (const char *name, unsigned short port,
@ -132,21 +161,7 @@ resolve_name_standard (const char *name, unsigned short port,
if (ret)
{
aibuf = NULL;
switch (ret)
{
case EAI_AGAIN: err = gpg_error (GPG_ERR_EAGAIN); break;
case EAI_BADFLAGS: err = gpg_error (GPG_ERR_INV_FLAG); break;
case EAI_FAIL: err = gpg_error (GPG_ERR_SERVER_FAILED); break;
case EAI_MEMORY: err = gpg_error (GPG_ERR_ENOMEM); break;
case EAI_NODATA: err = gpg_error (GPG_ERR_NO_DATA); break;
case EAI_NONAME: err = gpg_error (GPG_ERR_NO_NAME); break;
case EAI_SERVICE: err = gpg_error (GPG_ERR_NOT_SUPPORTED); break;
case EAI_ADDRFAMILY:err = gpg_error (GPG_ERR_EADDRNOTAVAIL); break;
case EAI_FAMILY: err = gpg_error (GPG_ERR_EAFNOSUPPORT); break;
case EAI_SOCKTYPE: err = gpg_error (GPG_ERR_ESOCKTNOSUPPORT); break;
case EAI_SYSTEM: err = gpg_error_from_syserror (); break;
default: err = gpg_error (GPG_ERR_UNKNOWN_ERRNO); break;
}
err = map_eai_to_gpg_error (ret);
goto leave;
}
@ -193,6 +208,66 @@ resolve_name_standard (const char *name, unsigned short port,
}
/* Resolve an address using the standard system function. */
static gpg_error_t
resolve_addr_standard (const struct sockaddr *addr, int addrlen,
unsigned int flags, char **r_name)
{
gpg_error_t err;
int ec;
char *buffer, *p;
int buflen;
*r_name = NULL;
buflen = NI_MAXHOST;
buffer = xtrymalloc (buflen + 2 + 1);
if (!buffer)
return gpg_error_from_syserror ();
if ((flags & DNS_NUMERICHOST) || tor_mode)
ec = EAI_NONAME;
else
ec = getnameinfo (addr, addrlen, buffer, buflen, NULL, 0, NI_NAMEREQD);
if (!ec && *buffer == '[')
ec = EAI_FAIL; /* A name may never start with a bracket. */
else if (ec == EAI_NONAME)
{
p = buffer;
if (addr->sa_family == AF_INET6 && (flags & DNS_WITHBRACKET))
{
*p++ = '[';
buflen -= 2;
}
ec = getnameinfo (addr, addrlen, p, buflen, NULL, 0, NI_NUMERICHOST);
if (!ec && addr->sa_family == AF_INET6 && (flags & DNS_WITHBRACKET))
strcat (buffer, "]");
}
if (ec)
err = map_eai_to_gpg_error (ec);
else
{
p = xtryrealloc (buffer, strlen (buffer)+1);
if (!p)
err = gpg_error_from_syserror ();
else
{
buffer = p;
err = 0;
}
}
if (err)
xfree (buffer);
else
*r_name = buffer;
return err;
}
/* This a wrapper around getaddrinfo with slighly different semantics.
NAME is the name to resolve.
PORT is the requested port or 0.
@ -219,6 +294,85 @@ resolve_dns_name (const char *name, unsigned short port,
}
gpg_error_t
resolve_dns_addr (const struct sockaddr *addr, int addrlen,
unsigned int flags, char **r_name)
{
#ifdef USE_ADNS_disabled_for_now
return resolve_addr_adns (addr, addrlen, flags, r_name);
#else
return resolve_addr_standard (addr, addrlen, flags, r_name);
#endif
}
/* Check whether NAME is an IP address. Returns true if it is either
an IPv6 or IPv4 numerical address. */
int
is_ip_address (const char *name)
{
const char *s;
int ndots, dblcol, n;
if (*name == '[')
return 1; /* yes: A legal DNS name may not contain this character;
this mut be bracketed v6 address. */
if (*name == '.')
return 0; /* No. A leading dot is not a valid IP address. */
/* Check whether this is a v6 address. */
ndots = n = dblcol = 0;
for (s=name; *s; s++)
{
if (*s == ':')
{
ndots++;
if (s[1] == ':')
{
ndots++;
if (dblcol)
return 0; /* No: Only one "::" allowed. */
dblcol++;
if (s[1])
s++;
}
n = 0;
}
else if (*s == '.')
goto legacy;
else if (!strchr ("0123456789abcdefABCDEF", *s))
return 0; /* No: Not a hex digit. */
else if (++n > 4)
return 0; /* To many digits in a group. */
}
if (ndots > 7)
return 0; /* No: Too many colons. */
else if (ndots > 1)
return 1; /* Yes: At least 2 colons indicate an v6 address. */
legacy:
/* Check whether it is legacy IP address. */
ndots = n = 0;
for (s=name; *s; s++)
{
if (*s == '.')
{
if (s[1] == '.')
return 0; /* No: Douple dot. */
if (atoi (s+1) > 255)
return 0; /* No: Ipv4 byte value too large. */
ndots++;
n = 0;
}
else if (!strchr ("0123456789", *s))
return 0; /* No: Not a digit. */
else if (++n > 3)
return 0; /* No: More than 3 digits. */
}
return !!(ndots == 3);
}
#ifdef USE_ADNS
/* Init ADNS and store the new state at R_STATE. Returns 0 on
success; prints an error message and returns an error code on