nss_dns: Split getanswer_ptr from getanswer_r
And expand the use of name_ok and qtype in getanswer_ptr (the former also in getanswer_r). After further cleanups, not much code will be shared between the two functions. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This commit is contained in:
Florian Weimer
parent
857c890d9b
commit
0dcc43e998
|
|
@ -116,6 +116,11 @@ static enum nss_status getanswer_r (struct resolv_context *ctx,
|
|||
struct hostent *result, char *buffer,
|
||||
size_t buflen, int *errnop, int *h_errnop,
|
||||
int map, int32_t *ttlp, char **canonp);
|
||||
static enum nss_status getanswer_ptr (const querybuf *answer, int anslen,
|
||||
const char *qname,
|
||||
struct hostent *result, char *buffer,
|
||||
size_t buflen, int *errnop,
|
||||
int *h_errnop, int32_t *ttlp);
|
||||
|
||||
static enum nss_status gaih_getanswer (const querybuf *answer1, int anslen1,
|
||||
const querybuf *answer2, int anslen2,
|
||||
|
|
@ -561,9 +566,8 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
|
|||
return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
|
||||
}
|
||||
|
||||
status = getanswer_r
|
||||
(ctx, host_buffer.buf, n, qbuf, T_PTR, result, buffer, buflen,
|
||||
errnop, h_errnop, 0 /* XXX */, ttlp, NULL);
|
||||
status = getanswer_ptr (host_buffer.buf, n, qbuf, result,
|
||||
buffer, buflen, errnop, h_errnop, ttlp);
|
||||
if (host_buffer.buf != orig_host_buffer)
|
||||
free (host_buffer.buf);
|
||||
if (status != NSS_STATUS_SUCCESS)
|
||||
|
|
@ -659,8 +663,6 @@ getanswer_r (struct resolv_context *ctx,
|
|||
int haveanswer, had_error;
|
||||
char *bp, **ap, **hap;
|
||||
char tbuf[MAXDNAME];
|
||||
const char *tname;
|
||||
int (*name_ok) (const char *);
|
||||
u_char packtmp[NS_MAXCDNAME];
|
||||
int have_to_map = 0;
|
||||
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data);
|
||||
|
|
@ -679,22 +681,8 @@ getanswer_r (struct resolv_context *ctx,
|
|||
if (buflen - sizeof (struct host_data) != linebuflen)
|
||||
linebuflen = INT_MAX;
|
||||
|
||||
tname = qname;
|
||||
result->h_name = NULL;
|
||||
end_of_message = answer->buf + anslen;
|
||||
switch (qtype)
|
||||
{
|
||||
case T_A:
|
||||
case T_AAAA:
|
||||
name_ok = __libc_res_hnok;
|
||||
break;
|
||||
case T_PTR:
|
||||
name_ok = __libc_res_dnok;
|
||||
break;
|
||||
default:
|
||||
*errnop = ENOENT;
|
||||
return NSS_STATUS_UNAVAIL; /* XXX should be abort(); */
|
||||
}
|
||||
|
||||
/*
|
||||
* find first satisfactory answer
|
||||
|
|
@ -729,7 +717,7 @@ getanswer_r (struct resolv_context *ctx,
|
|||
*h_errnop = NO_RECOVERY;
|
||||
return NSS_STATUS_UNAVAIL;
|
||||
}
|
||||
if (__glibc_unlikely (name_ok (bp) == 0))
|
||||
if (__glibc_unlikely (__libc_res_hnok (bp) == 0))
|
||||
{
|
||||
errno = EBADMSG;
|
||||
*errnop = EBADMSG;
|
||||
|
|
@ -783,7 +771,7 @@ getanswer_r (struct resolv_context *ctx,
|
|||
n = -1;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n < 0 || (*name_ok) (bp) == 0))
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_hnok (bp) == 0))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
|
|
@ -816,7 +804,7 @@ getanswer_r (struct resolv_context *ctx,
|
|||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
|
||||
if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME)
|
||||
if (type == T_CNAME)
|
||||
{
|
||||
/* A CNAME could also have a TTL entry. */
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
|
|
@ -826,7 +814,7 @@ getanswer_r (struct resolv_context *ctx,
|
|||
continue;
|
||||
n = __libc_dn_expand (answer->buf, end_of_message, cp,
|
||||
tbuf, sizeof tbuf);
|
||||
if (__glibc_unlikely (n < 0 || (*name_ok) (tbuf) == 0))
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_hnok (tbuf) == 0))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
|
|
@ -857,35 +845,6 @@ getanswer_r (struct resolv_context *ctx,
|
|||
continue;
|
||||
}
|
||||
|
||||
if (qtype == T_PTR && type == T_CNAME)
|
||||
{
|
||||
/* A CNAME could also have a TTL entry. */
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
*ttlp = ttl;
|
||||
|
||||
n = __libc_dn_expand (answer->buf, end_of_message, cp,
|
||||
tbuf, sizeof tbuf);
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_dnok (tbuf) == 0))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
cp += n;
|
||||
/* Get canonical name. */
|
||||
n = strlen (tbuf) + 1; /* For the \0. */
|
||||
if (__glibc_unlikely (n > linebuflen))
|
||||
goto too_small;
|
||||
if (__glibc_unlikely (n >= MAXHOSTNAMELEN))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
tname = bp;
|
||||
bp = __mempcpy (bp, tbuf, n); /* Cannot overflow. */
|
||||
linebuflen -= n;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (type == T_A && qtype == T_AAAA && map)
|
||||
have_to_map = 1;
|
||||
else if (__glibc_unlikely (type != qtype))
|
||||
|
|
@ -896,35 +855,6 @@ getanswer_r (struct resolv_context *ctx,
|
|||
|
||||
switch (type)
|
||||
{
|
||||
case T_PTR:
|
||||
if (__glibc_unlikely (__strcasecmp (tname, bp) != 0))
|
||||
{
|
||||
cp += n;
|
||||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
|
||||
n = __ns_name_unpack (answer->buf, end_of_message, cp,
|
||||
packtmp, sizeof packtmp);
|
||||
if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
|
||||
{
|
||||
if (__glibc_unlikely (errno == EMSGSIZE))
|
||||
goto too_small;
|
||||
|
||||
n = -1;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_hnok (bp) == 0))
|
||||
{
|
||||
++had_error;
|
||||
break;
|
||||
}
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
*ttlp = ttl;
|
||||
/* bind would put multiple PTR records as aliases, but we don't do
|
||||
that. */
|
||||
result->h_name = bp;
|
||||
*h_errnop = NETDB_SUCCESS;
|
||||
return NSS_STATUS_SUCCESS;
|
||||
case T_A:
|
||||
case T_AAAA:
|
||||
if (__glibc_unlikely (__strcasecmp (result->h_name, bp) != 0))
|
||||
|
|
@ -1030,6 +960,292 @@ getanswer_r (struct resolv_context *ctx,
|
|||
? NSS_STATUS_NOTFOUND : NSS_STATUS_TRYAGAIN);
|
||||
}
|
||||
|
||||
static enum nss_status
|
||||
getanswer_ptr (const querybuf *answer, int anslen, const char *qname,
|
||||
struct hostent *result, char *buffer, size_t buflen,
|
||||
int *errnop, int *h_errnop, int32_t *ttlp)
|
||||
{
|
||||
struct host_data
|
||||
{
|
||||
char *aliases[MAX_NR_ALIASES];
|
||||
unsigned char host_addr[16]; /* IPv4 or IPv6 */
|
||||
char *h_addr_ptrs[0];
|
||||
} *host_data;
|
||||
int linebuflen;
|
||||
const HEADER *hp;
|
||||
const u_char *end_of_message, *cp;
|
||||
int n, ancount, qdcount;
|
||||
int haveanswer, had_error;
|
||||
char *bp, **ap, **hap;
|
||||
char tbuf[MAXDNAME];
|
||||
const char *tname;
|
||||
u_char packtmp[NS_MAXCDNAME];
|
||||
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data);
|
||||
buffer += pad;
|
||||
buflen = buflen > pad ? buflen - pad : 0;
|
||||
if (__glibc_unlikely (buflen < sizeof (struct host_data)))
|
||||
{
|
||||
/* The buffer is too small. */
|
||||
too_small:
|
||||
*errnop = ERANGE;
|
||||
*h_errnop = NETDB_INTERNAL;
|
||||
return NSS_STATUS_TRYAGAIN;
|
||||
}
|
||||
host_data = (struct host_data *) buffer;
|
||||
linebuflen = buflen - sizeof (struct host_data);
|
||||
if (buflen - sizeof (struct host_data) != linebuflen)
|
||||
linebuflen = INT_MAX;
|
||||
|
||||
tname = qname;
|
||||
result->h_name = NULL;
|
||||
end_of_message = answer->buf + anslen;
|
||||
|
||||
/*
|
||||
* find first satisfactory answer
|
||||
*/
|
||||
hp = &answer->hdr;
|
||||
ancount = ntohs (hp->ancount);
|
||||
qdcount = ntohs (hp->qdcount);
|
||||
cp = answer->buf + HFIXEDSZ;
|
||||
if (__glibc_unlikely (qdcount != 1))
|
||||
{
|
||||
*h_errnop = NO_RECOVERY;
|
||||
return NSS_STATUS_UNAVAIL;
|
||||
}
|
||||
if (sizeof (struct host_data) + (ancount + 1) * sizeof (char *) >= buflen)
|
||||
goto too_small;
|
||||
bp = (char *) &host_data->h_addr_ptrs[ancount + 1];
|
||||
linebuflen -= (ancount + 1) * sizeof (char *);
|
||||
|
||||
n = __ns_name_unpack (answer->buf, end_of_message, cp,
|
||||
packtmp, sizeof packtmp);
|
||||
if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
|
||||
{
|
||||
if (__glibc_unlikely (errno == EMSGSIZE))
|
||||
goto too_small;
|
||||
|
||||
n = -1;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n < 0))
|
||||
{
|
||||
*errnop = errno;
|
||||
*h_errnop = NO_RECOVERY;
|
||||
return NSS_STATUS_UNAVAIL;
|
||||
}
|
||||
if (__glibc_unlikely (__libc_res_dnok (bp) == 0))
|
||||
{
|
||||
errno = EBADMSG;
|
||||
*errnop = EBADMSG;
|
||||
*h_errnop = NO_RECOVERY;
|
||||
return NSS_STATUS_UNAVAIL;
|
||||
}
|
||||
cp += n + QFIXEDSZ;
|
||||
|
||||
ap = host_data->aliases;
|
||||
*ap = NULL;
|
||||
result->h_aliases = host_data->aliases;
|
||||
hap = host_data->h_addr_ptrs;
|
||||
*hap = NULL;
|
||||
result->h_addr_list = host_data->h_addr_ptrs;
|
||||
haveanswer = 0;
|
||||
had_error = 0;
|
||||
|
||||
while (ancount-- > 0 && cp < end_of_message && had_error == 0)
|
||||
{
|
||||
int type, class;
|
||||
|
||||
n = __ns_name_unpack (answer->buf, end_of_message, cp,
|
||||
packtmp, sizeof packtmp);
|
||||
if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
|
||||
{
|
||||
if (__glibc_unlikely (errno == EMSGSIZE))
|
||||
goto too_small;
|
||||
|
||||
n = -1;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_dnok (bp) == 0))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
cp += n; /* name */
|
||||
|
||||
if (__glibc_unlikely (cp + 10 > end_of_message))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
|
||||
NS_GET16 (type, cp);
|
||||
NS_GET16 (class, cp);
|
||||
int32_t ttl;
|
||||
NS_GET32 (ttl, cp);
|
||||
NS_GET16 (n, cp); /* RDATA length. */
|
||||
|
||||
if (end_of_message - cp < n)
|
||||
{
|
||||
/* RDATA extends beyond the end of the packet. */
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (class != C_IN))
|
||||
{
|
||||
/* XXX - debug? syslog? */
|
||||
cp += n;
|
||||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
|
||||
if (type == T_CNAME)
|
||||
{
|
||||
/* A CNAME could also have a TTL entry. */
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
*ttlp = ttl;
|
||||
|
||||
n = __libc_dn_expand (answer->buf, end_of_message, cp,
|
||||
tbuf, sizeof tbuf);
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_dnok (tbuf) == 0))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
cp += n;
|
||||
/* Get canonical name. */
|
||||
n = strlen (tbuf) + 1; /* For the \0. */
|
||||
if (__glibc_unlikely (n > linebuflen))
|
||||
goto too_small;
|
||||
if (__glibc_unlikely (n >= MAXHOSTNAMELEN))
|
||||
{
|
||||
++had_error;
|
||||
continue;
|
||||
}
|
||||
tname = bp;
|
||||
bp = __mempcpy (bp, tbuf, n); /* Cannot overflow. */
|
||||
linebuflen -= n;
|
||||
continue;
|
||||
}
|
||||
|
||||
switch (type)
|
||||
{
|
||||
case T_PTR:
|
||||
if (__glibc_unlikely (__strcasecmp (tname, bp) != 0))
|
||||
{
|
||||
cp += n;
|
||||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
|
||||
n = __ns_name_unpack (answer->buf, end_of_message, cp,
|
||||
packtmp, sizeof packtmp);
|
||||
if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1)
|
||||
{
|
||||
if (__glibc_unlikely (errno == EMSGSIZE))
|
||||
goto too_small;
|
||||
|
||||
n = -1;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n < 0 || __libc_res_hnok (bp) == 0))
|
||||
{
|
||||
++had_error;
|
||||
break;
|
||||
}
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
*ttlp = ttl;
|
||||
/* bind would put multiple PTR records as aliases, but we don't do
|
||||
that. */
|
||||
result->h_name = bp;
|
||||
*h_errnop = NETDB_SUCCESS;
|
||||
return NSS_STATUS_SUCCESS;
|
||||
case T_A:
|
||||
case T_AAAA:
|
||||
if (__glibc_unlikely (__strcasecmp (result->h_name, bp) != 0))
|
||||
{
|
||||
cp += n;
|
||||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
|
||||
/* Stop parsing at a record whose length is incorrect. */
|
||||
if (n != rrtype_to_rdata_length (type))
|
||||
{
|
||||
++had_error;
|
||||
break;
|
||||
}
|
||||
|
||||
/* Skip records of the wrong type. */
|
||||
if (n != result->h_length)
|
||||
{
|
||||
cp += n;
|
||||
continue;
|
||||
}
|
||||
if (!haveanswer)
|
||||
{
|
||||
int nn;
|
||||
|
||||
/* We compose a single hostent out of the entire chain of
|
||||
entries, so the TTL of the hostent is essentially the lowest
|
||||
TTL in the chain. */
|
||||
if (ttlp != NULL && ttl < *ttlp)
|
||||
*ttlp = ttl;
|
||||
result->h_name = bp;
|
||||
nn = strlen (bp) + 1; /* for the \0 */
|
||||
bp += nn;
|
||||
linebuflen -= nn;
|
||||
}
|
||||
|
||||
/* Provide sufficient alignment for both address
|
||||
families. */
|
||||
enum { align = 4 };
|
||||
_Static_assert ((align % __alignof__ (struct in_addr)) == 0,
|
||||
"struct in_addr alignment");
|
||||
_Static_assert ((align % __alignof__ (struct in6_addr)) == 0,
|
||||
"struct in6_addr alignment");
|
||||
{
|
||||
char *new_bp = PTR_ALIGN_UP (bp, align);
|
||||
linebuflen -= new_bp - bp;
|
||||
bp = new_bp;
|
||||
}
|
||||
|
||||
if (__glibc_unlikely (n > linebuflen))
|
||||
goto too_small;
|
||||
bp = __mempcpy (*hap++ = bp, cp, n);
|
||||
cp += n;
|
||||
linebuflen -= n;
|
||||
break;
|
||||
default:
|
||||
cp += n;
|
||||
continue; /* XXX - had_error++ ? */
|
||||
}
|
||||
if (had_error == 0)
|
||||
++haveanswer;
|
||||
}
|
||||
|
||||
if (haveanswer > 0)
|
||||
{
|
||||
*ap = NULL;
|
||||
*hap = NULL;
|
||||
|
||||
if (result->h_name == NULL)
|
||||
{
|
||||
n = strlen (qname) + 1; /* For the \0. */
|
||||
if (n > linebuflen)
|
||||
goto too_small;
|
||||
if (n >= MAXHOSTNAMELEN)
|
||||
goto no_recovery;
|
||||
result->h_name = bp;
|
||||
bp = __mempcpy (bp, qname, n); /* Cannot overflow. */
|
||||
linebuflen -= n;
|
||||
}
|
||||
|
||||
*h_errnop = NETDB_SUCCESS;
|
||||
return NSS_STATUS_SUCCESS;
|
||||
}
|
||||
no_recovery:
|
||||
*h_errnop = NO_RECOVERY;
|
||||
*errnop = ENOENT;
|
||||
return NSS_STATUS_TRYAGAIN;
|
||||
}
|
||||
|
||||
static enum nss_status
|
||||
gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
|
||||
|
|
|
|||
Loading…
Reference in a new issue