mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-24 14:00:30 +00:00
nss_files: Use struct scratch_buffer for gethostbyname [BZ #18023]
This commit is contained in:
Florian Weimer
parent
0ff64d3a18
commit
78e806fd8c
@ -1,3 +1,9 @@
|
||||
2017-10-11 Florian Weimer <fweimer@redhat.com>
|
||||
|
||||
[BZ #18023]
|
||||
* nss/nss_files/files-hosts.c (gethostbyname3_multi): Use struct
|
||||
scratch_buffer. Eliminate gotos.
|
||||
|
||||
2017-10-11 Joseph Myers <joseph@codesourcery.com>
|
||||
|
||||
* sysdeps/ieee754/ldbl-opt/s_clog10l.c: Use
|
||||
|
||||
@ -22,6 +22,7 @@
|
||||
#include <arpa/nameser.h>
|
||||
#include <netdb.h>
|
||||
#include <resolv/resolv-internal.h>
|
||||
#include <scratch_buffer.h>
|
||||
|
||||
|
||||
/* Get implementation for some internal functions. */
|
||||
@ -121,15 +122,12 @@ gethostbyname3_multi (FILE * stream, const char *name, int af,
|
||||
int *errnop, int *herrnop, int flags)
|
||||
{
|
||||
/* We have to get all host entries from the file. */
|
||||
size_t tmp_buflen = MIN (buflen, 4096);
|
||||
char tmp_buffer_stack[tmp_buflen]
|
||||
__attribute__ ((__aligned__ (__alignof__ (struct hostent_data))));
|
||||
char *tmp_buffer = tmp_buffer_stack;
|
||||
struct scratch_buffer tmp_buffer;
|
||||
scratch_buffer_init (&tmp_buffer);
|
||||
struct hostent tmp_result_buf;
|
||||
int naddrs = 1;
|
||||
int naliases = 0;
|
||||
char *bufferend;
|
||||
bool tmp_buffer_malloced = false;
|
||||
enum nss_status status;
|
||||
|
||||
while (result->h_aliases[naliases] != NULL)
|
||||
@ -137,181 +135,165 @@ gethostbyname3_multi (FILE * stream, const char *name, int af,
|
||||
|
||||
bufferend = (char *) &result->h_aliases[naliases + 1];
|
||||
|
||||
again:
|
||||
while ((status = internal_getent (stream, &tmp_result_buf, tmp_buffer,
|
||||
tmp_buflen, errnop, herrnop, af,
|
||||
flags))
|
||||
== NSS_STATUS_SUCCESS)
|
||||
while (true)
|
||||
{
|
||||
int matches = 1;
|
||||
struct hostent *old_result = result;
|
||||
result = &tmp_result_buf;
|
||||
/* The following piece is a bit clumsy but we want to use the
|
||||
`LOOKUP_NAME_CASE' value. The optimizer should do its
|
||||
job. */
|
||||
do
|
||||
status = internal_getent (stream, &tmp_result_buf, tmp_buffer.data,
|
||||
tmp_buffer.length, errnop, herrnop, af,
|
||||
flags);
|
||||
/* Enlarge the buffer if necessary. */
|
||||
if (status == NSS_STATUS_TRYAGAIN && *herrnop == NETDB_INTERNAL
|
||||
&& *errnop == ERANGE)
|
||||
{
|
||||
LOOKUP_NAME_CASE (h_name, h_aliases)
|
||||
result = old_result;
|
||||
if (!scratch_buffer_grow (&tmp_buffer))
|
||||
{
|
||||
*errnop = ENOMEM;
|
||||
/* *herrnop and status already have the right value. */
|
||||
break;
|
||||
}
|
||||
/* Loop around and retry with a larger buffer. */
|
||||
}
|
||||
while ((matches = 0));
|
||||
|
||||
if (matches)
|
||||
else if (status == NSS_STATUS_SUCCESS)
|
||||
{
|
||||
/* We could be very clever and try to recycle a few bytes
|
||||
in the buffer instead of generating new arrays. But
|
||||
we are not doing this here since it's more work than
|
||||
it's worth. Simply let the user provide a bit bigger
|
||||
buffer. */
|
||||
char **new_h_addr_list;
|
||||
char **new_h_aliases;
|
||||
int newaliases = 0;
|
||||
size_t newstrlen = 0;
|
||||
int cnt;
|
||||
/* A line was read. Check that it matches the search
|
||||
criteria. */
|
||||
|
||||
/* Count the new aliases and the length of the strings. */
|
||||
while (tmp_result_buf.h_aliases[newaliases] != NULL)
|
||||
int matches = 1;
|
||||
struct hostent *old_result = result;
|
||||
result = &tmp_result_buf;
|
||||
/* The following piece is a bit clumsy but we want to use
|
||||
the `LOOKUP_NAME_CASE' value. The optimizer should do
|
||||
its job. */
|
||||
do
|
||||
{
|
||||
char *cp = tmp_result_buf.h_aliases[newaliases];
|
||||
++newaliases;
|
||||
newstrlen += strlen (cp) + 1;
|
||||
LOOKUP_NAME_CASE (h_name, h_aliases)
|
||||
result = old_result;
|
||||
}
|
||||
/* If the real name is different add it also to the
|
||||
aliases. This means that there is a duplication
|
||||
in the alias list but this is really the user's
|
||||
problem. */
|
||||
if (strcmp (old_result->h_name,
|
||||
tmp_result_buf.h_name) != 0)
|
||||
while ((matches = 0));
|
||||
|
||||
if (matches)
|
||||
{
|
||||
++newaliases;
|
||||
newstrlen += strlen (tmp_result_buf.h_name) + 1;
|
||||
}
|
||||
/* We could be very clever and try to recycle a few bytes
|
||||
in the buffer instead of generating new arrays. But
|
||||
we are not doing this here since it's more work than
|
||||
it's worth. Simply let the user provide a bit bigger
|
||||
buffer. */
|
||||
char **new_h_addr_list;
|
||||
char **new_h_aliases;
|
||||
int newaliases = 0;
|
||||
size_t newstrlen = 0;
|
||||
int cnt;
|
||||
|
||||
/* Make sure bufferend is aligned. */
|
||||
assert ((bufferend - (char *) 0) % sizeof (char *) == 0);
|
||||
/* Count the new aliases and the length of the strings. */
|
||||
while (tmp_result_buf.h_aliases[newaliases] != NULL)
|
||||
{
|
||||
char *cp = tmp_result_buf.h_aliases[newaliases];
|
||||
++newaliases;
|
||||
newstrlen += strlen (cp) + 1;
|
||||
}
|
||||
/* If the real name is different add it also to the
|
||||
aliases. This means that there is a duplication
|
||||
in the alias list but this is really the user's
|
||||
problem. */
|
||||
if (strcmp (old_result->h_name,
|
||||
tmp_result_buf.h_name) != 0)
|
||||
{
|
||||
++newaliases;
|
||||
newstrlen += strlen (tmp_result_buf.h_name) + 1;
|
||||
}
|
||||
|
||||
/* Now we can check whether the buffer is large enough.
|
||||
16 is the maximal size of the IP address. */
|
||||
if (bufferend + 16 + (naddrs + 2) * sizeof (char *)
|
||||
+ roundup (newstrlen, sizeof (char *))
|
||||
+ (naliases + newaliases + 1) * sizeof (char *)
|
||||
>= buffer + buflen)
|
||||
{
|
||||
*errnop = ERANGE;
|
||||
*herrnop = NETDB_INTERNAL;
|
||||
status = NSS_STATUS_TRYAGAIN;
|
||||
goto out;
|
||||
}
|
||||
/* Make sure bufferend is aligned. */
|
||||
assert ((bufferend - (char *) 0) % sizeof (char *) == 0);
|
||||
|
||||
new_h_addr_list =
|
||||
(char **) (bufferend
|
||||
+ roundup (newstrlen, sizeof (char *))
|
||||
+ 16);
|
||||
new_h_aliases =
|
||||
(char **) ((char *) new_h_addr_list
|
||||
+ (naddrs + 2) * sizeof (char *));
|
||||
/* Now we can check whether the buffer is large enough.
|
||||
16 is the maximal size of the IP address. */
|
||||
if (bufferend + 16 + (naddrs + 2) * sizeof (char *)
|
||||
+ roundup (newstrlen, sizeof (char *))
|
||||
+ (naliases + newaliases + 1) * sizeof (char *)
|
||||
>= buffer + buflen)
|
||||
{
|
||||
*errnop = ERANGE;
|
||||
*herrnop = NETDB_INTERNAL;
|
||||
status = NSS_STATUS_TRYAGAIN;
|
||||
break;
|
||||
}
|
||||
|
||||
/* Copy the old data in the new arrays. */
|
||||
for (cnt = 0; cnt < naddrs; ++cnt)
|
||||
new_h_addr_list[cnt] = old_result->h_addr_list[cnt];
|
||||
new_h_addr_list =
|
||||
(char **) (bufferend
|
||||
+ roundup (newstrlen, sizeof (char *))
|
||||
+ 16);
|
||||
new_h_aliases =
|
||||
(char **) ((char *) new_h_addr_list
|
||||
+ (naddrs + 2) * sizeof (char *));
|
||||
|
||||
for (cnt = 0; cnt < naliases; ++cnt)
|
||||
new_h_aliases[cnt] = old_result->h_aliases[cnt];
|
||||
/* Copy the old data in the new arrays. */
|
||||
for (cnt = 0; cnt < naddrs; ++cnt)
|
||||
new_h_addr_list[cnt] = old_result->h_addr_list[cnt];
|
||||
|
||||
/* Store the new strings. */
|
||||
cnt = 0;
|
||||
while (tmp_result_buf.h_aliases[cnt] != NULL)
|
||||
{
|
||||
new_h_aliases[naliases++] = bufferend;
|
||||
bufferend = (__stpcpy (bufferend,
|
||||
tmp_result_buf.h_aliases[cnt])
|
||||
+ 1);
|
||||
++cnt;
|
||||
}
|
||||
for (cnt = 0; cnt < naliases; ++cnt)
|
||||
new_h_aliases[cnt] = old_result->h_aliases[cnt];
|
||||
|
||||
if (cnt < newaliases)
|
||||
{
|
||||
new_h_aliases[naliases++] = bufferend;
|
||||
bufferend = __stpcpy (bufferend,
|
||||
tmp_result_buf.h_name) + 1;
|
||||
}
|
||||
/* Store the new strings. */
|
||||
cnt = 0;
|
||||
while (tmp_result_buf.h_aliases[cnt] != NULL)
|
||||
{
|
||||
new_h_aliases[naliases++] = bufferend;
|
||||
bufferend = (__stpcpy (bufferend,
|
||||
tmp_result_buf.h_aliases[cnt])
|
||||
+ 1);
|
||||
++cnt;
|
||||
}
|
||||
|
||||
/* Final NULL pointer. */
|
||||
new_h_aliases[naliases] = NULL;
|
||||
if (cnt < newaliases)
|
||||
{
|
||||
new_h_aliases[naliases++] = bufferend;
|
||||
bufferend = __stpcpy (bufferend,
|
||||
tmp_result_buf.h_name) + 1;
|
||||
}
|
||||
|
||||
/* Round up the buffer end address. */
|
||||
bufferend += (sizeof (char *)
|
||||
- ((bufferend - (char *) 0)
|
||||
% sizeof (char *))) % sizeof (char *);
|
||||
/* Final NULL pointer. */
|
||||
new_h_aliases[naliases] = NULL;
|
||||
|
||||
/* Now the new address. */
|
||||
new_h_addr_list[naddrs++] =
|
||||
memcpy (bufferend, tmp_result_buf.h_addr,
|
||||
tmp_result_buf.h_length);
|
||||
/* Round up the buffer end address. */
|
||||
bufferend += (sizeof (char *)
|
||||
- ((bufferend - (char *) 0)
|
||||
% sizeof (char *))) % sizeof (char *);
|
||||
|
||||
/* Also here a final NULL pointer. */
|
||||
new_h_addr_list[naddrs] = NULL;
|
||||
/* Now the new address. */
|
||||
new_h_addr_list[naddrs++] =
|
||||
memcpy (bufferend, tmp_result_buf.h_addr,
|
||||
tmp_result_buf.h_length);
|
||||
|
||||
/* Store the new array pointers. */
|
||||
old_result->h_aliases = new_h_aliases;
|
||||
old_result->h_addr_list = new_h_addr_list;
|
||||
/* Also here a final NULL pointer. */
|
||||
new_h_addr_list[naddrs] = NULL;
|
||||
|
||||
/* Compute the new buffer end. */
|
||||
bufferend = (char *) &new_h_aliases[naliases + 1];
|
||||
assert (bufferend <= buffer + buflen);
|
||||
/* Store the new array pointers. */
|
||||
old_result->h_aliases = new_h_aliases;
|
||||
old_result->h_addr_list = new_h_addr_list;
|
||||
|
||||
result = old_result;
|
||||
}
|
||||
}
|
||||
/* Compute the new buffer end. */
|
||||
bufferend = (char *) &new_h_aliases[naliases + 1];
|
||||
assert (bufferend <= buffer + buflen);
|
||||
|
||||
if (status == NSS_STATUS_TRYAGAIN)
|
||||
{
|
||||
size_t newsize = 2 * tmp_buflen;
|
||||
if (tmp_buffer_malloced)
|
||||
{
|
||||
char *newp = realloc (tmp_buffer, newsize);
|
||||
if (newp != NULL)
|
||||
{
|
||||
assert ((((uintptr_t) newp)
|
||||
& (__alignof__ (struct hostent_data) - 1))
|
||||
== 0);
|
||||
tmp_buffer = newp;
|
||||
tmp_buflen = newsize;
|
||||
goto again;
|
||||
}
|
||||
}
|
||||
else if (!__libc_use_alloca (buflen + newsize))
|
||||
{
|
||||
tmp_buffer = malloc (newsize);
|
||||
if (tmp_buffer != NULL)
|
||||
{
|
||||
assert ((((uintptr_t) tmp_buffer)
|
||||
& (__alignof__ (struct hostent_data) - 1))
|
||||
== 0);
|
||||
tmp_buffer_malloced = true;
|
||||
tmp_buflen = newsize;
|
||||
goto again;
|
||||
}
|
||||
}
|
||||
result = old_result;
|
||||
} /* If match was found. */
|
||||
|
||||
/* If no match is found, loop around and fetch another
|
||||
line. */
|
||||
|
||||
} /* status == NSS_STATUS_SUCCESS. */
|
||||
else
|
||||
{
|
||||
tmp_buffer
|
||||
= extend_alloca (tmp_buffer, tmp_buflen,
|
||||
newsize
|
||||
+ __alignof__ (struct hostent_data));
|
||||
tmp_buffer = (char *) (((uintptr_t) tmp_buffer
|
||||
+ __alignof__ (struct hostent_data)
|
||||
- 1)
|
||||
& ~(__alignof__ (struct hostent_data)
|
||||
- 1));
|
||||
goto again;
|
||||
}
|
||||
}
|
||||
else
|
||||
/* internal_getent returned an error. */
|
||||
break;
|
||||
} /* while (true) */
|
||||
|
||||
/* Propagate the NSS_STATUS_TRYAGAIN error to the caller. It means
|
||||
that we may not have loaded the complete result.
|
||||
NSS_STATUS_NOTFOUND, however, means that we reached the end of
|
||||
the file successfully. */
|
||||
if (status != NSS_STATUS_TRYAGAIN)
|
||||
status = NSS_STATUS_SUCCESS;
|
||||
out:
|
||||
if (tmp_buffer_malloced)
|
||||
free (tmp_buffer);
|
||||
|
||||
scratch_buffer_free (&tmp_buffer);
|
||||
return status;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user