#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv/resolv-internal.h>
+#include <scratch_buffer.h>
/* Get implementation for some internal functions. */
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)
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;
-
- /* Count the new aliases and the length of the strings. */
- while (tmp_result_buf.h_aliases[newaliases] != NULL)
+ /* A line was read. Check that it matches the search
+ criteria. */
+
+ 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;
+
+ /* 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;
+ }
- /* Make sure bufferend is aligned. */
- assert ((bufferend - (char *) 0) % sizeof (char *) == 0);
+ /* Make sure bufferend is aligned. */
+ assert ((bufferend - (char *) 0) % sizeof (char *) == 0);
- /* 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;
- }
+ /* 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;
+ }
- new_h_addr_list =
- (char **) (bufferend
- + roundup (newstrlen, sizeof (char *))
- + 16);
- new_h_aliases =
- (char **) ((char *) new_h_addr_list
- + (naddrs + 2) * sizeof (char *));
+ new_h_addr_list =
+ (char **) (bufferend
+ + roundup (newstrlen, sizeof (char *))
+ + 16);
+ new_h_aliases =
+ (char **) ((char *) new_h_addr_list
+ + (naddrs + 2) * sizeof (char *));
- /* 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];
+ /* 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];
- for (cnt = 0; cnt < naliases; ++cnt)
- new_h_aliases[cnt] = old_result->h_aliases[cnt];
+ for (cnt = 0; cnt < naliases; ++cnt)
+ new_h_aliases[cnt] = old_result->h_aliases[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;
- }
+ /* 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;
+ }
- if (cnt < newaliases)
- {
- new_h_aliases[naliases++] = bufferend;
- bufferend = __stpcpy (bufferend,
- tmp_result_buf.h_name) + 1;
- }
+ if (cnt < newaliases)
+ {
+ new_h_aliases[naliases++] = bufferend;
+ bufferend = __stpcpy (bufferend,
+ tmp_result_buf.h_name) + 1;
+ }
- /* Final NULL pointer. */
- new_h_aliases[naliases] = NULL;
+ /* Final NULL pointer. */
+ new_h_aliases[naliases] = NULL;
- /* Round up the buffer end address. */
- bufferend += (sizeof (char *)
- - ((bufferend - (char *) 0)
- % sizeof (char *))) % sizeof (char *);
+ /* Round up the buffer end address. */
+ bufferend += (sizeof (char *)
+ - ((bufferend - (char *) 0)
+ % sizeof (char *))) % sizeof (char *);
- /* Now the new address. */
- new_h_addr_list[naddrs++] =
- memcpy (bufferend, tmp_result_buf.h_addr,
- tmp_result_buf.h_length);
+ /* Now the new address. */
+ new_h_addr_list[naddrs++] =
+ memcpy (bufferend, tmp_result_buf.h_addr,
+ tmp_result_buf.h_length);
- /* Also here a final NULL pointer. */
- new_h_addr_list[naddrs] = NULL;
+ /* Also here a final NULL pointer. */
+ new_h_addr_list[naddrs] = NULL;
- /* Store the new array pointers. */
- old_result->h_aliases = new_h_aliases;
- old_result->h_addr_list = new_h_addr_list;
+ /* Store the new array pointers. */
+ old_result->h_aliases = new_h_aliases;
+ old_result->h_addr_list = new_h_addr_list;
- /* Compute the new buffer end. */
- bufferend = (char *) &new_h_aliases[naliases + 1];
- assert (bufferend <= buffer + buflen);
+ /* Compute the new buffer end. */
+ bufferend = (char *) &new_h_aliases[naliases + 1];
+ assert (bufferend <= buffer + buflen);
- result = old_result;
- }
- }
+ result = old_result;
+ } /* If match was found. */
- 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;
- }
- }
+ /* 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;
}
git://sourceware.org / glibc.git / commitdiff