On Sun, Nov 11, 2018 at 06:32:53PM +0100, Bruno Flueckiger wrote:
> On 11.11.18 15:29, Florian Obser wrote:
> > On Sun, Nov 11, 2018 at 01:46:06PM +0100, Sebastian Benoit wrote:
> > > Bruno Flueckiger([email protected]) on 2018.11.11 10:31:34 +0100:
> > > > Hi
> > > >
> > > > When I run httpd(8) behind relayd(8) the access log of httpd contains
> > > > the IP address of relayd, but not the IP address of the client. I've
> > > > tried to match the logs of relayd(8) and httpd(8) using some scripting
> > > > and failed.
> > > >
> > > > So I've written a patch for httpd(8). It stores the content of the
> > > > X-Forwarded-For header in the third field of the log entry:
> > > >
> > > > www.example.com 192.0.2.99 192.0.2.134 - [11/Nov/2018:09:28:48 ...
> > > >
> > > > Cheers,
> > > > Bruno
> > >
> > > I'm not sure we should do this unconditionally. With no relayd or other
> > > proxy infront of httpd, this is (more) data the client controls.
> >
> > Isn't what httpd(8) currently logs apache's common log format? If
> > people are shoving that through webalizer or something that will
> > break. I don't think we can do this without a config option.
> > Do we need LogFormat?
> >
> > >
> > > Could this be a problem?
> > >
> > > code reads ok.
> > >
> > > /Benno
> > >
>
> I've extended my patch with an option to the log directive. Both log xff
> and log combined must be set for a server to log the content of the
> X-Forwarded-For header. If only log combined is set the log entries
> remain in the well-known format.
>
> This prevents clients from getting unwanted data in the log by default.
> And it makes sure the log format remains default until one decides
> actively to change it.
>From my experience with webservices is that today logging the IP is
seldomly good enough. Please also include X-Forwarded-Port and maybe
X-Forwarded-Proto.
In general thanks to CG-NAT logging only IP is a bit pointless.
--
:wq Claudio
> Index: usr.sbin/httpd/config.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/httpd/config.c,v
> retrieving revision 1.55
> diff -u -p -r1.55 config.c
> --- usr.sbin/httpd/config.c 20 Jun 2018 16:43:05 -0000 1.55
> +++ usr.sbin/httpd/config.c 11 Nov 2018 14:45:47 -0000
> @@ -427,6 +427,10 @@ config_getserver_config(struct httpd *en
> if ((srv_conf->flags & f) == 0)
> srv_conf->flags |= parent->flags & f;
>
> + f = SRVFLAG_XFF|SRVFLAG_NO_XFF;
> + if ((srv_conf->flags & f) == 0)
> + srv_conf->flags |= parent->flags & f;
> +
> f = SRVFLAG_AUTH|SRVFLAG_NO_AUTH;
> if ((srv_conf->flags & f) == 0) {
> srv_conf->flags |= parent->flags & f;
> Index: usr.sbin/httpd/httpd.conf.5
> ===================================================================
> RCS file: /cvs/src/usr.sbin/httpd/httpd.conf.5,v
> retrieving revision 1.101
> diff -u -p -r1.101 httpd.conf.5
> --- usr.sbin/httpd/httpd.conf.5 20 Jun 2018 16:43:05 -0000 1.101
> +++ usr.sbin/httpd/httpd.conf.5 11 Nov 2018 14:45:47 -0000
> @@ -455,6 +455,14 @@ If not specified, the default is
> Enable or disable logging to
> .Xr syslog 3
> instead of the log files.
> +.It Oo Ic no Oc Ic xff
> +Enable or disable logging of the request header
> +.Ar X-Forwarded-For
> +if
> +.Cm log combined
> +is set. This header can be set by a reverse proxy like
> +.Xr relayd 8
> +and should contain the IP address of the client.
> .El
> .It Ic pass
> Disable any previous
> Index: usr.sbin/httpd/httpd.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/httpd/httpd.h,v
> retrieving revision 1.142
> diff -u -p -r1.142 httpd.h
> --- usr.sbin/httpd/httpd.h 11 Oct 2018 09:52:22 -0000 1.142
> +++ usr.sbin/httpd/httpd.h 11 Nov 2018 14:45:47 -0000
> @@ -400,6 +400,8 @@ SPLAY_HEAD(client_tree, client);
> #define SRVFLAG_DEFAULT_TYPE 0x00800000
> #define SRVFLAG_PATH_REWRITE 0x01000000
> #define SRVFLAG_NO_PATH_REWRITE 0x02000000
> +#define SRVFLAG_XFF 0x04000000
> +#define SRVFLAG_NO_XFF 0x08000000
>
> #define SRVFLAG_BITS \
> "\10\01INDEX\02NO_INDEX\03AUTO_INDEX\04NO_AUTO_INDEX" \
> Index: usr.sbin/httpd/parse.y
> ===================================================================
> RCS file: /cvs/src/usr.sbin/httpd/parse.y,v
> retrieving revision 1.107
> diff -u -p -r1.107 parse.y
> --- usr.sbin/httpd/parse.y 1 Nov 2018 00:18:44 -0000 1.107
> +++ usr.sbin/httpd/parse.y 11 Nov 2018 14:45:47 -0000
> @@ -139,7 +139,7 @@ typedef struct {
> %token LISTEN LOCATION LOG LOGDIR MATCH MAXIMUM NO NODELAY OCSP ON
> PORT PREFORK
> %token PROTOCOLS REQUESTS ROOT SACK SERVER SOCKET STRIP STYLE SYSLOG
> TCP TICKET
> %token TIMEOUT TLS TYPE TYPES HSTS MAXAGE SUBDOMAINS DEFAULT PRELOAD
> REQUEST
> -%token ERROR INCLUDE AUTHENTICATE WITH BLOCK DROP RETURN PASS REWRITE
> +%token ERROR INCLUDE AUTHENTICATE WITH BLOCK DROP RETURN PASS REWRITE
> XFF
> %token CA CLIENT CRL OPTIONAL
> %token <v.string> STRING
> %token <v.number> NUMBER
> @@ -979,6 +979,10 @@ logflags : STYLE logstyle
> free($2);
> srv_conf->flags |= SRVFLAG_ERROR_LOG;
> }
> + | XFF {
> + srv_conf->flags &= ~SRVFLAG_NO_XFF;
> + srv_conf->flags |= SRVFLAG_XFF;
> + }
> ;
>
> logstyle : COMMON {
> @@ -1308,7 +1312,8 @@ lookup(char *s)
> { "tls", TLS },
> { "type", TYPE },
> { "types", TYPES },
> - { "with", WITH }
> + { "with", WITH },
> + { "xff", XFF }
> };
> const struct keywords *p;
>
> Index: usr.sbin/httpd/server_http.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/httpd/server_http.c,v
> retrieving revision 1.127
> diff -u -p -r1.127 server_http.c
> --- usr.sbin/httpd/server_http.c 4 Nov 2018 05:56:45 -0000 1.127
> +++ usr.sbin/httpd/server_http.c 11 Nov 2018 14:45:47 -0000
> @@ -1632,7 +1632,7 @@ server_log_http(struct client *clt, unsi
> static char tstamp[64];
> static char ip[INET6_ADDRSTRLEN];
> time_t t;
> - struct kv key, *agent, *referrer;
> + struct kv key, *agent, *referrer, *xff;
> struct tm *tm;
> struct server_config *srv_conf;
> struct http_descriptor *desc;
> @@ -1642,6 +1642,7 @@ server_log_http(struct client *clt, unsi
> char *version = NULL;
> char *referrer_v = NULL;
> char *agent_v = NULL;
> + char *xff_v = NULL;
>
> if ((srv_conf = clt->clt_srv_conf) == NULL)
> return (-1);
> @@ -1666,7 +1667,7 @@ server_log_http(struct client *clt, unsi
> *
> * httpd's format is similar to these Apache LogFormats:
> * "%v %h %l %u %t \"%r\" %>s %B"
> - * "%v %h %l %u %t \"%r\" %>s %B \"%{Referer}i\" \"%{User-agent}i\""
> + * "%v %h %a %u %t \"%r\" %>s %B \"%{Referer}i\" \"%{User-agent}i\""
> */
> switch (srv_conf->logformat) {
> case LOG_FORMAT_COMMON:
> @@ -1708,6 +1709,14 @@ server_log_http(struct client *clt, unsi
> agent->kv_value == NULL)
> agent = NULL;
>
> + xff = NULL;
> + if (srv_conf->flags & SRVFLAG_XFF) {
> + key.kv_key = "X-Forwarded-For";
> + if (((xff = kv_find(&desc->http_headers, &key)) != NULL
> + && xff->kv_value == NULL))
> + xff = NULL;
> + }
> +
> /* Use vis to encode input values from the header */
> if (clt->clt_remote_user &&
> stravis(&user, clt->clt_remote_user, HTTPD_LOGVIS) == -1)
> @@ -1718,6 +1727,9 @@ server_log_http(struct client *clt, unsi
> if (agent &&
> stravis(&agent_v, agent->kv_value, HTTPD_LOGVIS) == -1)
> goto done;
> + if (xff &&
> + stravis(&xff_v, xff->kv_value, HTTPD_LOGVIS) == -1)
> + goto done;
>
> /* The following should be URL-encoded */
> if (desc->http_path &&
> @@ -1728,10 +1740,10 @@ server_log_http(struct client *clt, unsi
> goto done;
>
> ret = evbuffer_add_printf(clt->clt_log,
> - "%s %s - %s [%s] \"%s %s%s%s%s%s\""
> + "%s %s %s %s [%s] \"%s %s%s%s%s%s\""
> " %03d %zu \"%s\" \"%s\"\n",
> - srv_conf->name, ip, clt->clt_remote_user == NULL ? "-" :
> - user, tstamp,
> + srv_conf->name, ip, xff == NULL ? "-" : xff_v,
> + clt->clt_remote_user == NULL ? "-" : user, tstamp,
> server_httpmethod_byid(desc->http_method),
> desc->http_path == NULL ? "" : path,
> desc->http_query == NULL ? "" : "?",
> @@ -1762,6 +1774,7 @@ done:
> free(version);
> free(referrer_v);
> free(agent_v);
> + free(xff_v);
>
> return (ret);
> }
>
