mod_proxy_html: use ap_expr to evaluate conditional URLMaps (03508164) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

modules/filters/mod_proxy_html.c

+48 −48

Original line number	Diff line number	Diff line
		@@ -44,8 +44,10 @@
		#include "apr_optional.h"
		#include "mod_xml2enc.h"
		#include "http_request.h"
		#include "ap_expr.h"

		/* globals set once at startup */
		static ap_rxplus_t* old_expr;
		static ap_regex_t* seek_meta;
		static const apr_strmatch_pattern* seek_content;
		static apr_status_t (xml2enc_charset)(request_rec, xmlCharEncoding, const char*) = NULL;
		@@ -71,11 +73,6 @@ typedef struct {
		unsigned int start;
		unsigned int end;
		} meta;
		typedef struct {
		const char* env;
		const char* val;
		int rel;
		} rewritecond;
		typedef struct urlmap {
		struct urlmap* next;
		unsigned int flags;
		@@ -85,7 +82,7 @@ typedef struct urlmap {
		ap_regex_t* r;
		} from;
		const char* to;
		rewritecond* cond;
		ap_expr_info_t *cond;
		} urlmap;
		typedef struct {
		urlmap* map;
		@@ -743,34 +740,20 @@ static const char* interpolate_vars(request_rec* r, const char* str)
		}
		static void fixup_rules(saxctxt* ctx)
		{
		const char* thisval;
		urlmap* newp;
		urlmap* p;
		urlmap* prev = NULL;
		request_rec* r = ctx->f->r;
		int has_cond;

		for (p = ctx->cfg->map; p; p = p->next) {
		has_cond = -1;
		if (p->cond != NULL) {
		thisval = apr_table_get(r->subprocess_env, p->cond->env);
		if (!p->cond->val) {
		/* required to be "anything" */
		if (thisval)
		has_cond = 1; /* satisfied */
		else
		has_cond = 0; /* unsatisfied */
		}
		else {
		if (thisval && !strcasecmp(p->cond->val, thisval)) {
		has_cond = 1; /* satisfied */
		const char *err;
		int ok = ap_expr_exec(r, p->cond, &err);
		if (err) {
		ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
		"Error evaluating expr: %s", err);
		}
		else {
		has_cond = 0; /* unsatisfied */
		}
		}
		if (((has_cond == 0) && (p->cond->rel ==1))
		\|\| ((has_cond == 1) && (p->cond->rel == -1))) {
		if (ok == 0) {
		continue; /* condition is unsatisfied */
		}
		}
		@@ -1027,10 +1010,11 @@ static void* proxy_html_merge(apr_pool_t* pool, void* BASE, void* ADD)
		}
		#define REGFLAG(n,s,c) ((s&&(ap_strchr_c((s),(c))!=NULL)) ? (n) : 0)
		#define XREGFLAG(n,s,c) ((!s\|\|(ap_strchr_c((s),(c))==NULL)) ? (n) : 0)
		static void comp_urlmap(apr_pool_t* pool, urlmap* newmap, const char* from,
		const char* to, const char* flags, const char* cond)
		static const char* comp_urlmap(cmd_parms cmd, urlmap newmap,
		const char* from, const char* to,
		const char* flags, const char* cond)
		{
		char* eq;
		const char *err = NULL;
		newmap->flags
		= XREGFLAG(M_HTML,flags,'h')
		\| XREGFLAG(M_EVENTS,flags,'e')
		@@ -1053,28 +1037,40 @@ static void comp_urlmap(apr_pool_t* pool, urlmap* newmap, const char* from,
		\| REGFLAG(AP_REG_ICASE,flags,'i')
		\| REGFLAG(AP_REG_NOSUB,flags,'n')
		\| REGFLAG(AP_REG_NEWLINE,flags,'s');
		newmap->from.r = ap_pregcomp(pool, from, newmap->regflags);
		newmap->from.r = ap_pregcomp(cmd->pool, from, newmap->regflags);
		newmap->to = to;
		}
		if (cond != NULL) {
		char* cond_copy;
		newmap->cond = apr_pcalloc(pool, sizeof(rewritecond));
		if (cond[0] == '!') {
		newmap->cond->rel = -1;
		newmap->cond->env = cond_copy = apr_pstrdup(pool, cond+1);
		} else {
		newmap->cond->rel = 1;
		newmap->cond->env = cond_copy = apr_pstrdup(pool, cond);
		/* back-compatibility: support old-style ENV expressions
		* by converting to ap_expr syntax.
		*
		* 1. var --> env(var)
		* 2. var=val --> env(var)=val
		* 3. !var --> !env(var)
		* 4. !var=val --> env(var)!=val
		*/
		char *newcond = NULL;
		if (ap_rxplus_exec(cmd->temp_pool, old_expr, cond, &newcond)) {
		/* we got a substitution. Check for the case (3) above
		* that the regexp gets wrong: a negation without a comparison.
		*/
		if ((cond[0] == '!') && !strchr(cond, '=')) {
		memmove(newcond+1, newcond, strlen(newcond)-1);
		newcond[0] = '!';
		}
		eq = ap_strchr(++cond_copy, '=');
		if (eq) {
		*eq = 0;
		newmap->cond->val = eq+1;
		cond = newcond;
		}
		#if 0
		newmap->cond = apr_palloc(pool, sizeof(ap_expr_info_t));
		err = ap_expr_parse(pool, tpool, newmap->cond, cond, NULL);
		#else
		newmap->cond = ap_expr_parse_cmd(cmd, cond, 0, &err, NULL);
		#endif
		}
		else {
		newmap->cond = NULL;
		}
		return err;
		}
		static const char* set_urlmap(cmd_parms* cmd, void* CFG, const char* args)
		{
		@@ -1109,8 +1105,7 @@ static const char* set_urlmap(cmd_parms* cmd, void* CFG, const char* args)
		else
		cfg->map = newmap;

		comp_urlmap(cmd->pool, newmap, from, to, flags, cond);
		return NULL;
		return comp_urlmap(cmd, newmap, from, to, flags, cond);
		}

		static const char* set_doctype(cmd_parms* cmd, void* CFG,
		@@ -1219,8 +1214,7 @@ static const command_rec proxy_html_cmds[] = {
		"Enable proxy-html and xml2enc filters"),
		{ NULL }
		};
		static int mod_proxy_html(apr_pool_t* p, apr_pool_t* p1, apr_pool_t* p2,
		server_rec* s)
		static int mod_proxy_html(apr_pool_t* p, apr_pool_t* p1, apr_pool_t* p2)
		{
		seek_meta = ap_pregcomp(p, "<meta[^>](http-equiv)[^>]>",
		AP_REG_EXTENDED\|AP_REG_ICASE);
		@@ -1239,6 +1233,9 @@ static int mod_proxy_html(apr_pool_t* p, apr_pool_t* p1, apr_pool_t* p2,
		"Without it, non-ASCII characters in proxied pages are "
		"likely to display incorrectly.");
		}

		/* old_expr only needs to last the life of the config phase */
		old_expr = ap_rxplus_compile(p1, "s/^(!)?(\\w+)((=)(.+))?$/reqenv('$2')$1$4'$5'/");
		return OK;
		}
		static void proxy_html_insert(request_rec* r)
		@@ -1257,7 +1254,10 @@ static void proxy_html_hooks(apr_pool_t* p)
		ap_register_output_filter_protocol("proxy-html", proxy_html_filter,
		NULL, AP_FTYPE_RESOURCE,
		AP_FILTER_PROTO_CHANGE\|AP_FILTER_PROTO_CHANGE_LENGTH);
		ap_hook_post_config(mod_proxy_html, NULL, NULL, APR_HOOK_MIDDLE);
		/* move this to pre_config so old_expr is available to interpret
		* old-style conditions on URL maps.
		*/
		ap_hook_pre_config(mod_proxy_html, NULL, NULL, APR_HOOK_MIDDLE);
		ap_hook_insert_filter(proxy_html_insert, NULL, aszSucc, APR_HOOK_MIDDLE);
		}
		module AP_MODULE_DECLARE_DATA proxy_html_module = {