Re: using a 3-tier mod_perl setup
On Sun, 16 Jul 2000, Gunther Birznieks wrote:
> Is any of this header rewriting already on Ralf's TODO list for mod_rewrite?
>
> Does it make sense to make mod_headers more complex? Or to add these
> features to mod_rewrite already?
>
> Just throwing the idea out there.
>
> This is an interesting module though.
>
I considered adding the ProxyHeaderRewrite and HeaderRewrite commands to
mod_rewrite, but I felt more comfortable mucking around in the much
simpler mod_headers. I'm not happy that I had to duplicate some code from
mod_rewrite, tho.
I did not find any TODO lists for mod_rewrite.
BTW, I have attached a newer patch for mod_headers, which fixes a bug of
mine with ProxyHeaderRewrite unset. (apply to a stock 1.3.12 mod_headers)
I'm glad you find it interesting - this is my first public module
contribution.
-Tim
-
(from my original post)
The attached patch
(cd apache_1.3.XX; patch -p1 < ProxyHeaderRewrite.p2.patch; make
install)
will add two commands to mod_headers:
HeaderRewrite - dynamically set headers for the client
ProxyHeaderRewrite - dynamically set headers for the upstream proxy
server
While the original mod_headers would allow you so say:
Header append Foo "burfl"
Now you can say
HeaderRewrite append Foo "%{ENV:BURFL}", using the full RewriteCond syntax
My current lightweight apache server config looks something like:
ProxyHeaderRewrite append X-Forwarded-For "%{REMOTE_ADDR}"
ProxyHeaderRewrite append X-Frontend-Host "%{HTTP_HOST}"
...
SSLOptions StdEnvVars
ProxyHeaderRewrite append X-SSL-Cipher "%{ENV:SSL_PROTOCOL}
%{ENV:SSL_CIPHER}"
--- apache_1.3.12.dist/src/modules/standard/mod_headers.c Wed Oct 27 02:26:53
1999
+++ apache_1.3.12/src/modules/standard/mod_headers.cThu Jul 13 16:53:11 2000
@@ -99,9 +99,52 @@
* To remove a header:
* Header unset Author
*
+ *
+ * Non-standard Additions:
+ *
+ *Most code is from mod_rewrite, by
+ * Ralf S. Engelschall
+ * [EMAIL PROTECTED]
+ *Assembled by Tim Bishop <[EMAIL PROTECTED]>
+ *
+ *
+ * HeaderRewrite (set headers to client using RewriteCond syntax)
+ *
+ * Syntax: HeaderRewrite action header rewriteValue
+ *
+ * This works the same as the header directive, except that full
+ * mod_rewrite RewriteCond interpolation is performed on the rewriteValue
+ * string. See http://www.apache.org/docs/mod/mod_rewrite.html#RewriteCond
+ * (Of course, back-references (%N, $N) have no meaning)
+ *
+ *
+ * ProxyHeaderRewrite (set headers sent to upstream servers (if proxying))
+ *
+ * Syntax: ProxyHeaderRewrite action header rewriteValue
+ *
+ * ProxyHeaderRewrite allows you to rewrite headers sent to upstream
+ * servers when your server is functioning as a proxy server.
+ * This is useful when you want to send additional header information
+ * to upstream servers.
+ *
+ * Bugs: Cannot rewrite the Host header with ProxyHeaderRewrite
+ *
+ * Examples:
+ *
+ *# tell upstream server the ip of the request
+ *ProxyHeaderRewrite append X-Forwarded-For "%{REMOTE_ADDR}"
+ *# tell upstream server info on SSL status
+ *
+ *SSLOptions StdEnvVars
+ *ProxyHeaderRewrite append X-SSL-Cipher "%{ENV:SSL_PROTOCOL}
+%{ENV:SSL_CIPHER}"
+ *
+ *# tell upstream server the virtual host used
+ *ProxyHeaderRewrite append X-Frontend-Host "%{HTTP:Host}"
+ *
*/
#include "httpd.h"
+#include "http_log.h"
#include "http_config.h"
typedef enum {
@@ -111,12 +154,50 @@
hdr_unset = 'u' /* unset header */
} hdr_actions;
+typedef enum {
+ hdr_string = 's', /* header is a string */
+ hdr_env_var = 'v', /* set header from env var */
+ hdr_interpolate = 'i' /* header needs to be interpolated (not yet!) */
+} hdr_value_type;
+
+typedef enum {
+ hdr_client = 'c', /* modify headers for client */
+ hdr_upstream = 'u'/* modify headers for upstream server */
+} hdr_header_target;
+
typedef struct {
-hdr_actions action;
-char *header;
-char *value;
+ hdr_actions action;
+ char *header;
+ char *value;
+ hdr_value_type value_type;
+ hdr_header_target header_target; /* one of hdr_client | hdr_upstream */
} header_entry;
+
+/* env variable interpolation support */
+static void expand_variables_inbuffer(request_rec *r, char *buf, int buf_len);
+static char *expand_variables(request_rec *r, char *str);
+static char *lookup_variable(request_rec *r, char *var);
+static char *lookup_header(request_rec *r, const char *name);
+
+#ifndef LONG_STRING_LEN
+#define LONG_STRING_LEN 2048
+#endif
+
+/* REMOTE_NAME returns the hostname, or the dotted quad if the
+ * hostname lookup fails. It will force a DNS lookup according
+ * to the HostnameLookups setting.
+ * from httd_core.h
+ */
+#define REMOTE_N
Re: using a 3-tier mod_perl setup
Is any of this header rewriting already on Ralf's TODO list for mod_rewrite?
Does it make sense to make mod_headers more complex? Or to add these
features to mod_rewrite already?
Just throwing the idea out there.
This is an interesting module though.
At 09:56 AM 7/11/00 -0700, Tim Bishop wrote:
>I am running a 3-tier mod_perl setup as advised by the Guide:
>
> Lightweight apache <-> mod_perl apache <-> db server.
>
>One of the problems with this setup is that the mod_perl apache no longer
>knows some details about the client request, like the client IP.
>
>I used Ask Bjoern Hansen's module proxy_add_forward, which adds a
>"X-Forwarded-For" header to to the request as it is forwarded to the
>mod_perl apache server.
>
>After I added SSL to my lightweight (but gaining!) apache, I found
>I needed some SSL connection information on the mod_perl server as well.
>
>I recently fell in love with mod_rewrite, and so I ported some of its
>capabilities to mod_headers
>
>The attached patch
> (cd apache_1.3.XX; patch -p1 < ProxyHeaderRewrite.patch; make install)
>will add two commands to mod_headers:
>
>HeaderRewrite - dynamically set headers for the client
>ProxyHeaderRewrite - dynamically set headers for the upstream proxy
> server
>
>While the original mod_headers would allow you so say:
>
>Header append Foo "burfl"
>
>Now you can say
>
>HeaderRewrite append Foo "%{ENV:BURFL}", using the full RewriteCond syntax
>
>
>
>My current lightweight apache server config looks something like:
>
>ProxyHeaderRewrite append X-Forwarded-For "%{REMOTE_ADDR}"
>ProxyHeaderRewrite append X-Frontend-Host "%{HTTP_HOST}"
>
>...
>SSLOptions StdEnvVars
>ProxyHeaderRewrite append X-SSL-Cipher "%{ENV:SSL_PROTOCOL}
> %{ENV:SSL_CIPHER}"
>
>
>
>Did I miss another way to do this? Is this patch useful?
>
>
>BTW,
>
>the Guide on server architecture:
>http://perl.apache.org/guide/strategy.html
>
>Ask Bjoern Hansen's module proxy_add_forward
>http://www.cpan.org/authors/id/ABH/mod_proxy_add_forward.c
>
>
>-Tim
__
Gunther Birznieks ([EMAIL PROTECTED])
eXtropia - The Web Technology Company
http://www.extropia.com/
using a 3-tier mod_perl setup
I am running a 3-tier mod_perl setup as advised by the Guide:
Lightweight apache <-> mod_perl apache <-> db server.
One of the problems with this setup is that the mod_perl apache no longer
knows some details about the client request, like the client IP.
I used Ask Bjoern Hansen's module proxy_add_forward, which adds a
"X-Forwarded-For" header to to the request as it is forwarded to the
mod_perl apache server.
After I added SSL to my lightweight (but gaining!) apache, I found
I needed some SSL connection information on the mod_perl server as well.
I recently fell in love with mod_rewrite, and so I ported some of its
capabilities to mod_headers
The attached patch
(cd apache_1.3.XX; patch -p1 < ProxyHeaderRewrite.patch; make install)
will add two commands to mod_headers:
HeaderRewrite - dynamically set headers for the client
ProxyHeaderRewrite - dynamically set headers for the upstream proxy server
While the original mod_headers would allow you so say:
Header append Foo "burfl"
Now you can say
HeaderRewrite append Foo "%{ENV:BURFL}", using the full RewriteCond syntax
My current lightweight apache server config looks something like:
ProxyHeaderRewrite append X-Forwarded-For "%{REMOTE_ADDR}"
ProxyHeaderRewrite append X-Frontend-Host "%{HTTP_HOST}"
...
SSLOptions StdEnvVars
ProxyHeaderRewrite append X-SSL-Cipher "%{ENV:SSL_PROTOCOL} %{ENV:SSL_CIPHER}"
Did I miss another way to do this? Is this patch useful?
BTW,
the Guide on server architecture:
http://perl.apache.org/guide/strategy.html
Ask Bjoern Hansen's module proxy_add_forward
http://www.cpan.org/authors/id/ABH/mod_proxy_add_forward.c
-Tim
--- apache_1.3.12.dist/src/modules/standard/mod_headers.c Wed Oct 27 09:26:53
1999
+++ apache_1.3.12/src/modules/standard/mod_headers.cTue Jul 11 00:38:26 2000
@@ -99,9 +99,52 @@
* To remove a header:
* Header unset Author
*
+ *
+ * Non-standard Additions:
+ *
+ *Most code is from mod_rewrite, by
+ * Ralf S. Engelschall
+ * [EMAIL PROTECTED]
+ *Assembled by Tim Bishop <[EMAIL PROTECTED]>
+ *
+ *
+ * HeaderRewrite (set headers to client using RewriteCond syntax)
+ *
+ * Syntax: HeaderRewrite action header rewriteValue
+ *
+ * This works the same as the header directive, except that full
+ * mod_rewrite RewriteCond interpolation is performed on the rewriteValue
+ * string. See http://www.apache.org/docs/mod/mod_rewrite.html#RewriteCond
+ * (Of course, back-references (%N, $N) have no meaning)
+ *
+ *
+ * ProxyHeaderRewrite (set headers sent to upstream servers (if proxying))
+ *
+ * Syntax: ProxyHeaderRewrite action header rewriteValue
+ *
+ * ProxyHeaderRewrite allows you to rewrite headers sent to upstream
+ * servers when your server is functioning as a proxy server.
+ * This is useful when you want to send additional header information
+ * to upstream servers.
+ *
+ * Bugs: Cannot rewrite the Host header with ProxyHeaderRewrite
+ *
+ * Examples:
+ *
+ *# tell upstream server the ip of the request
+ *ProxyHeaderRewrite append X-Forwarded-For "%{REMOTE_ADDR}"
+ *# tell upstream server info on SSL status
+ *
+ *SSLOptions StdEnvVars
+ *ProxyHeaderRewrite append X-SSL-Cipher "%{ENV:SSL_PROTOCOL}
+%{ENV:SSL_CIPHER}"
+ *
+ *# tell upstream server the virtual host used
+ *ProxyHeaderRewrite append X-Frontend-Host "%{HTTP:Host}"
+ *
*/
#include "httpd.h"
+#include "http_log.h"
#include "http_config.h"
typedef enum {
@@ -111,12 +154,50 @@
hdr_unset = 'u' /* unset header */
} hdr_actions;
+typedef enum {
+ hdr_string = 's', /* header is a string */
+ hdr_env_var = 'v', /* set header from env var */
+ hdr_interpolate = 'i' /* header needs to be interpolated (not yet!) */
+} hdr_value_type;
+
+typedef enum {
+ hdr_client = 'c', /* modify headers for client */
+ hdr_upstream = 'u'/* modify headers for upstream server */
+} hdr_header_target;
+
typedef struct {
-hdr_actions action;
-char *header;
-char *value;
+ hdr_actions action;
+ char *header;
+ char *value;
+ hdr_value_type value_type;
+ hdr_header_target header_target; /* one of hdr_client | hdr_upstream */
} header_entry;
+
+/* env variable interpolation support */
+static void expand_variables_inbuffer(request_rec *r, char *buf, int buf_len);
+static char *expand_variables(request_rec *r, char *str);
+static char *lookup_variable(request_rec *r, char *var);
+static char *lookup_header(request_rec *r, const char *name);
+
+#ifndef LONG_STRING_LEN
+#define LONG_STRING_LEN 2048
+#endif
+
+/* REMOTE_NAME returns the hostname, or the dotted quad if the
+ * hostname lookup fails. It will force a DNS lookup according
+ * to the HostnameLookups setting.
+ * from httd_core.h
+ */
+#define REM
