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Posted to dev@httpd.apache.org by Ruediger Pluem <rp...@apache.org> on 2008/02/25 21:49:55 UTC

Re: svn commit: r630974 - in /httpd/httpd/trunk/modules/ssl: ssl_engine_config.c ssl_private.h ssl_scache.c ssl_scache_dbm.c ssl_scache_dc.c ssl_scache_memcache.c ssl_scache_shmcb.c


On 02/25/2008 09:09 PM, jorton@apache.org wrote:
> Author: jorton
> Date: Mon Feb 25 12:09:38 2008
> New Revision: 630974
> 
> URL: http://svn.apache.org/viewvc?rev=630974&view=rev
> Log:
> Session cache interface redesign, Part 4:
> 
> Move provider-specific configuration handling down into the provider
> code.  Eliminate all use of SSLModConfigRec within provider code.
> 
> * modules/ssl/ssl_private.h (modssl_sesscache_provider): Add 'create'
>   function which creates and configures the cache provider, before
>   initialisation.  Change 'init' function to take the context pointer
>   as an input parameter, and reorder to be first.
> 
> * modules/ssl/ssl_scache.c (ssl_scache_init): Adjust accordingly.
> 
> * modules/ssl/ssl_scache_memcache.c (struct context): Add servers
>   field.
>   (ssl_scache_mc_create): New function.
>   (ssl_scache_mc_init): Use servers from context not SSLModConfigRec.
> 
> * modules/ssl/ssl_scache_dbm.c (struct context): Define.
>   (ssl_scache_dbm_create): New function.
>   (ssl_scache_dbm_init, ssl_scache_dbm_kill): Adjust to use filename
>   and pool from context.
>   (ssl_scache_dbm_store, ssl_scache_dbm_retrieve,
>   ssl_scache_dbm_status): Use filename from context.  Use context pool
>   for temp storage of the DBM object, and clear before use.
>   (ssl_scache_dbm_expire): Remove static tLast; use last_expiry from
>   context.  Use context pool for temp storage and clear before use.
> 
> * modules/ssl/ssl_scache_dc.c (struct context): Add target field.
>   (ssl_scache_dc_init, ssl_scache_dc_status): Use target from context.
> 
> * modules/ssl/ssl_scache_shmcb.c (struct context): Add data_file,
>   shm_size fields.
>   (ssl_scache_shmcb_create): New function; moved argument parsing
>   logic from ssl_cmd_SSLSessionCache
>   (ssl_scache_shmcb_init, ssl_scache_shmcb_status): Use config from
>   context.
> 
> * modules/ssl/ssl_engine_config.c (ssl_config_global_create): Remove
>   handling of old provider-specific fields.
>   (ssl_cmd_SSLSessionCache): Call provider ->create function to parse
>   the argument and create provider-specific context structure.
> 
> Modified:
>     httpd/httpd/trunk/modules/ssl/ssl_engine_config.c
>     httpd/httpd/trunk/modules/ssl/ssl_private.h
>     httpd/httpd/trunk/modules/ssl/ssl_scache.c
>     httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c
>     httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c
>     httpd/httpd/trunk/modules/ssl/ssl_scache_memcache.c
>     httpd/httpd/trunk/modules/ssl/ssl_scache_shmcb.c
> 


>
> Modified: httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c?rev=630974&r1=630973&r2=630974&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c (original)
> +++ httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c Mon Feb 25 12:09:38 2008
> @@ -26,19 +26,43 @@
>  
>  #include "ssl_private.h"
>  
> -static void ssl_scache_dbm_expire(void *context, server_rec *s);
> +/* Use of the context structure must be thread-safe after the initial
> + * create/init; callers must hold the mutex. */
> +struct context {
> +    const char *data_file;
> +    /* Pool must only be used with the mutex held. */
> +    apr_pool_t *pool;
> +    time_t last_expiry;
> +};
> +
> +static void ssl_scache_dbm_expire(struct context *ctx, server_rec *s);
>  
>  static void ssl_scache_dbm_remove(void *context, server_rec *s, UCHAR *id, int idlen,
>                                    apr_pool_t *p);
>  
> -static apr_status_t ssl_scache_dbm_init(server_rec *s, void **context, apr_pool_t *p)
> +static const char *ssl_scache_dbm_create(void **context, const char *arg, 
> +                                         apr_pool_t *tmp, apr_pool_t *p)
> +{
> +    struct context *ctx;
> +
> +    *context = ctx = apr_pcalloc(p, sizeof *ctx);

Hm. Don't we need to set ctx->pool to p or create a subpool of p and
assign it to ctx->pool?

> +
> +    ctx->data_file = ap_server_root_relative(p, arg);
> +    if (!ctx->data_file) {
> +        return apr_psprintf(tmp, "Invalid cache file path %s", arg);
> +    }
> +    
> +    return NULL;
> +}
> +
> +static apr_status_t ssl_scache_dbm_init(void *context, server_rec *s, apr_pool_t *p)
>  {
> -    SSLModConfigRec *mc = myModConfig(s);
> +    struct context *ctx = context;
>      apr_dbm_t *dbm;
>      apr_status_t rv;
>  
>      /* for the DBM we need the data file */
> -    if (mc->szSessionCacheDataFile == NULL) {
> +    if (ctx->data_file == NULL) {
>          ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
>                       "SSLSessionCache required");
>          return APR_EINVAL;

> @@ -274,12 +291,12 @@
>  
>      /* and delete it from the DBM file */
>      ssl_mutex_on(s);

Any particular reason why we do not clear ctx->pool here?

> -    if ((rv = apr_dbm_open(&dbm, mc->szSessionCacheDataFile,
> +    if ((rv = apr_dbm_open(&dbm, ctx->data_file,
>              APR_DBM_RWCREATE, SSL_DBM_FILE_MODE, p)) != APR_SUCCESS) {
>          ap_log_error(APLOG_MARK, APLOG_ERR, rv, s,
>                       "Cannot open SSLSessionCache DBM file `%s' for writing "
>                       "(delete)",
> -                     mc->szSessionCacheDataFile);
> +                     ctx->data_file);
>          ssl_mutex_off(s);
>          return;
>      }

> Modified: httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c?rev=630974&r1=630973&r2=630974&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c (original)
> +++ httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c Mon Feb 25 12:09:38 2008
> @@ -49,22 +49,28 @@
>  */
>  
>  struct context {
> +    /* Configured target server: */
> +    const char *target;
> +    /* distcache client context: */
>      DC_CTX *dc;
>  };
>  
> -static apr_status_t ssl_scache_dc_init(server_rec *s, void **context, apr_pool_t *p)
> +static const char *ssl_scache_dc_create(void **context, const char *arg, 
> +                                        apr_pool_t *tmp, apr_pool_t *p)
>  {
> -    DC_CTX *dc;
> -    SSLModConfigRec *mc = myModConfig(s);
>      struct context *ctx;
>  
> -    /*
> -     * Create a session context
> -     */
> -    if (mc->szSessionCacheDataFile == NULL) {
> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache required");
> -        return APR_EINVAL;
> -    }

Why don't we check any if arg == NULL as a replacement for the if statement above?

> +    ctx = *context = apr_palloc(p, sizeof *ctx);
> +    
> +    ctx->target = apr_pstrdup(p, arg);
> +
> +    return NULL;
> +}
> +
> +static apr_status_t ssl_scache_dc_init(void *context, server_rec *s, apr_pool_t *p)
> +{
> +    struct context *ctx = ctx;
> +
>  #if 0
>      /* If a "persistent connection" mode of operation is preferred, you *must*
>       * also use the PIDCHECK flag to ensure fork()'d processes don't interlace


> Modified: httpd/httpd/trunk/modules/ssl/ssl_scache_memcache.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/ssl/ssl_scache_memcache.c?rev=630974&r1=630973&r2=630974&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/ssl/ssl_scache_memcache.c (original)
> +++ httpd/httpd/trunk/modules/ssl/ssl_scache_memcache.c Mon Feb 25 12:09:38 2008
> @@ -68,10 +68,23 @@
>  #endif
>  
>  struct context {
> +    const char *servers;
>      apr_memcache_t *mc;
>  };
>  
> -static apr_status_t ssl_scache_mc_init(server_rec *s, void **context, apr_pool_t *p)
> +static const char *ssl_scache_mc_create(void **context, const char *arg, 
> +                                        apr_pool_t *tmp, apr_pool_t *p)
> +{
> +    struct context *ctx;
> +    
> +    *context = ctx = apr_palloc(p, sizeof *ctx);
> +
> +    ctx->servers = apr_pstrdup(p, arg);

Why don't we check any if arg == NULL as a replacement for the if statement below
checking mc->szSessionCacheDataFile == NULL


> +
> +    return NULL;
> +}
> +
> +static apr_status_t ssl_scache_mc_init(void *context, server_rec *s, apr_pool_t *p)
>  {
>      apr_status_t rv;
>      int thread_limit = 0;
> @@ -79,18 +92,12 @@
>      char *cache_config;
>      char *split;
>      char *tok;
> -    SSLModConfigRec *mc = myModConfig(s);
> -    struct context *ctx = apr_palloc(p, sizeof *ctx);
> +    struct context *ctx = context;
>  
>      ap_mpm_query(AP_MPMQ_HARD_LIMIT_THREADS, &thread_limit);
>  
> -    if (mc->szSessionCacheDataFile == NULL) {
> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache required");
> -        return APR_EINVAL;
> -    }
> -
>      /* Find all the servers in the first run to get a total count */
> -    cache_config = apr_pstrdup(p, mc->szSessionCacheDataFile);
> +    cache_config = apr_pstrdup(p, ctx->servers);
>      split = apr_strtok(cache_config, ",", &tok);
>      while (split) {
>          nservers++;

Regards

Rüdiger

Re: svn commit: r630974 - in /httpd/httpd/trunk/modules/ssl: ssl_engine_config.c ssl_private.h ssl_scache.c ssl_scache_dbm.c ssl_scache_dc.c ssl_scache_memcache.c ssl_scache_shmcb.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 02/25/2008 11:40 PM, Ruediger Pluem wrote:
> 
> 
> On 02/25/2008 11:22 PM, Ruediger Pluem wrote:
>>
>>
>> On 02/25/2008 10:45 PM, Joe Orton wrote:
>>> On Mon, Feb 25, 2008 at 09:49:55PM +0100, Ruediger Pluem wrote:
>>>> On 02/25/2008 09:09 PM, jorton@apache.org wrote:
>>>>> Author: jorton
>>>>> Date: Mon Feb 25 12:09:38 2008
>>>>> New Revision: 630974
>>
>>>>> -    if (mc->szSessionCacheDataFile == NULL) {
>>>>> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache 
>>>>> required");
>>>>> -        return APR_EINVAL;
>>>>> -    }
>>>> Why don't we check any if arg == NULL as a replacement for the if 
>>>> statement above?
>>>
>>> Sorry, I should have mentioned this in the changelog message.  In 
>>> both cases of this, the code will always be passed a non-NULL arg 
>>> parameter 
>>
>> Hm, but you are supplying sep + 1 which is not NULL but can point to 
>> '\0'.
>> Shouldn't we check for this?
>>
>>> unless a pstrdup fails (which by policy will be ignored anyway).  I 
>>> think these checks may have just been a copy'n'paste legacy from the 
>>> shmcb code, which has genuine config argument parsing failure cases.
>>>
>>> Again, thanks for the detailed review!
> 
> Running the perl test suit I saw some regressions with core dumps:
> 
> t/modules/status.t                        1    1 100.00%  1
> t/security/CVE-2006-5752.t                2    2 100.00%  1-2
> t/security/CVE-2007-6388.t                2    2 100.00%  1-2
> 
> There might be something rotten in the mod_ssl status hook
> now.

Ah. The following patch fixes this:

Index: modules/ssl/ssl_scache.c
===================================================================
--- modules/ssl/ssl_scache.c    (Revision 631020)
+++ modules/ssl/ssl_scache.c    (Arbeitskopie)
@@ -143,7 +143,7 @@
  {
      SSLModConfigRec *mc = myModConfig(r->server);

-    if (mc == NULL || flags & AP_STATUS_SHORT)
+    if (mc == NULL || flags & AP_STATUS_SHORT || mc->sesscache == NULL)
          return OK;

      ap_rputs("<hr>\n", r);


Regards

Rüdiger

Re: svn commit: r630974 - in /httpd/httpd/trunk/modules/ssl: ssl_engine_config.c ssl_private.h ssl_scache.c ssl_scache_dbm.c ssl_scache_dc.c ssl_scache_memcache.c ssl_scache_shmcb.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 02/25/2008 11:22 PM, Ruediger Pluem wrote:
> 
> 
> On 02/25/2008 10:45 PM, Joe Orton wrote:
>> On Mon, Feb 25, 2008 at 09:49:55PM +0100, Ruediger Pluem wrote:
>>> On 02/25/2008 09:09 PM, jorton@apache.org wrote:
>>>> Author: jorton
>>>> Date: Mon Feb 25 12:09:38 2008
>>>> New Revision: 630974
> 
>>>> -    if (mc->szSessionCacheDataFile == NULL) {
>>>> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache 
>>>> required");
>>>> -        return APR_EINVAL;
>>>> -    }
>>> Why don't we check any if arg == NULL as a replacement for the if 
>>> statement above?
>>
>> Sorry, I should have mentioned this in the changelog message.  In both 
>> cases of this, the code will always be passed a non-NULL arg parameter 
> 
> Hm, but you are supplying sep + 1 which is not NULL but can point to '\0'.
> Shouldn't we check for this?
> 
>> unless a pstrdup fails (which by policy will be ignored anyway).  I 
>> think these checks may have just been a copy'n'paste legacy from the 
>> shmcb code, which has genuine config argument parsing failure cases.
>>
>> Again, thanks for the detailed review!

Running the perl test suit I saw some regressions with core dumps:

t/modules/status.t                        1    1 100.00%  1
t/security/CVE-2006-5752.t                2    2 100.00%  1-2
t/security/CVE-2007-6388.t                2    2 100.00%  1-2

There might be something rotten in the mod_ssl status hook
now.

Regards

Rüdiger


Re: svn commit: r630974 - in /httpd/httpd/trunk/modules/ssl: ssl_engine_config.c ssl_private.h ssl_scache.c ssl_scache_dbm.c ssl_scache_dc.c ssl_scache_memcache.c ssl_scache_shmcb.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 02/25/2008 10:45 PM, Joe Orton wrote:
> On Mon, Feb 25, 2008 at 09:49:55PM +0100, Ruediger Pluem wrote:
>> On 02/25/2008 09:09 PM, jorton@apache.org wrote:
>>> Author: jorton
>>> Date: Mon Feb 25 12:09:38 2008
>>> New Revision: 630974

>>> -    if (mc->szSessionCacheDataFile == NULL) {
>>> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache required");
>>> -        return APR_EINVAL;
>>> -    }
>> Why don't we check any if arg == NULL as a replacement for the if statement above?
> 
> Sorry, I should have mentioned this in the changelog message.  In both 
> cases of this, the code will always be passed a non-NULL arg parameter 

Hm, but you are supplying sep + 1 which is not NULL but can point to '\0'.
Shouldn't we check for this?

> unless a pstrdup fails (which by policy will be ignored anyway).  I 
> think these checks may have just been a copy'n'paste legacy from the 
> shmcb code, which has genuine config argument parsing failure cases.
> 
> Again, thanks for the detailed review!

You are welcome.

Regards

Rüdiger


Re: svn commit: r630974 - in /httpd/httpd/trunk/modules/ssl: ssl_engine_config.c ssl_private.h ssl_scache.c ssl_scache_dbm.c ssl_scache_dc.c ssl_scache_memcache.c ssl_scache_shmcb.c

Posted by Joe Orton <jo...@redhat.com>.
On Mon, Feb 25, 2008 at 09:49:55PM +0100, Ruediger Pluem wrote:
> On 02/25/2008 09:09 PM, jorton@apache.org wrote:
>> Author: jorton
>> Date: Mon Feb 25 12:09:38 2008
>> New Revision: 630974
>>
>> URL: http://svn.apache.org/viewvc?rev=630974&view=rev
>> Log:
>> Session cache interface redesign, Part 4:
...
>> --- httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c (original)
>> +++ httpd/httpd/trunk/modules/ssl/ssl_scache_dbm.c Mon Feb 25 12:09:38 2008
...
>> +static const char *ssl_scache_dbm_create(void **context, const char *arg, 
>> +                                         apr_pool_t *tmp, apr_pool_t *p)
>> +{
>> +    struct context *ctx;
>> +
>> +    *context = ctx = apr_pcalloc(p, sizeof *ctx);
>
> Hm. Don't we need to set ctx->pool to p or create a subpool of p and
> assign it to ctx->pool?

Yes indeed, I already found this out with a little trip through gdb.  
Fixed in r630990.

>> @@ -274,12 +291,12 @@
>>       /* and delete it from the DBM file */
>>      ssl_mutex_on(s);
>
> Any particular reason why we do not clear ctx->pool here?

I missed that, and it wasn't even using ctx->pool later; thanks!

...
>> --- httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c (original)
>> +++ httpd/httpd/trunk/modules/ssl/ssl_scache_dc.c Mon Feb 25 12:09:38 2008
>> @@ -49,22 +49,28 @@
>>  */
>>   struct context {
>> +    /* Configured target server: */
>> +    const char *target;
>> +    /* distcache client context: */
>>      DC_CTX *dc;
>>  };
>>  -static apr_status_t ssl_scache_dc_init(server_rec *s, void **context, apr_pool_t *p)
>> +static const char *ssl_scache_dc_create(void **context, const char *arg, 
>> +                                        apr_pool_t *tmp, apr_pool_t *p)
>>  {
>> -    DC_CTX *dc;
>> -    SSLModConfigRec *mc = myModConfig(s);
>>      struct context *ctx;
>>  -    /*
>> -     * Create a session context
>> -     */
>> -    if (mc->szSessionCacheDataFile == NULL) {
>> -        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, "SSLSessionCache required");
>> -        return APR_EINVAL;
>> -    }
>
> Why don't we check any if arg == NULL as a replacement for the if statement above?

Sorry, I should have mentioned this in the changelog message.  In both 
cases of this, the code will always be passed a non-NULL arg parameter 
unless a pstrdup fails (which by policy will be ignored anyway).  I 
think these checks may have just been a copy'n'paste legacy from the 
shmcb code, which has genuine config argument parsing failure cases.

Again, thanks for the detailed review!

Regards,

joe