From 4c58663041dbfdb751066da695af95e3aa83cbe7 Mon Sep 17 00:00:00 2001
From: Robert James Kaes <rjkaes@users.sourceforge.net>
Date: Tue, 16 Aug 2005 04:03:19 +0000
Subject: * [Refactor] Moved Reverse Proxy Code Moved the reverse proxy code
 from reqs.c into it's own files (reverse_proxy.c).  The code in reqs.c is way
 too complicated, so I want to move unrelated code into their own files to
 simplify the main concepts in reqs.c.

---
 src/reverse_proxy.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 src/reverse_proxy.c

(limited to 'src/reverse_proxy.c')

diff --git a/src/reverse_proxy.c b/src/reverse_proxy.c
new file mode 100644
index 0000000..40f15f4
--- /dev/null
+++ b/src/reverse_proxy.c
@@ -0,0 +1,154 @@
+/* $Id: reverse_proxy.c,v 1.1 2005-08-16 04:03:19 rjkaes Exp $
+ *
+ * Allow tinyproxy to be used as a reverse proxy.
+ *
+ * Copyright (C) 1999-2005  Robert James Kaes (rjkaes@users.sourceforge.net)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include "tinyproxy.h"
+#include "reverse_proxy.h"
+
+#include "conns.h"
+#include "heap.h"
+#include "htmlerror.h"
+#include "log.h"
+
+/*
+ * Add entry to the reversepath list
+ */
+void
+reversepath_add(const char *path, const char *url)
+{
+        struct reversepath *reverse;
+
+        if (url == NULL) {
+                log_message(LOG_WARNING,
+                            "Illegal reverse proxy rule: missing url");
+                return;
+        }
+
+        if (!strstr(url, "://")) {
+                log_message(LOG_WARNING,
+                            "Skipping reverse proxy rule: '%s' is not a valid url",
+                            url);
+                return;
+        }
+
+        if (path && *path != '/') {
+                log_message(LOG_WARNING,
+                            "Skipping reverse proxy rule: path '%s' doesn't start with a /",
+                            path);
+                return;
+        }
+
+        if (!(reverse = safemalloc(sizeof(struct reversepath)))) {
+                log_message(LOG_ERR,
+                            "Unable to allocate memory in reversepath_add()");
+                return;
+        }
+
+        if (!path)
+                reverse->path = safestrdup("/");
+        else
+                reverse->path = safestrdup(path);
+
+        reverse->url = safestrdup(url);
+
+        reverse->next = config.reversepath_list;
+        config.reversepath_list = reverse;
+
+        log_message(LOG_INFO,
+                    "Added reverse proxy rule: %s -> %s", reverse->path,
+                    reverse->url);
+}
+
+/*
+ * Check if a request url is in the reversepath list
+ */
+struct reversepath *
+reversepath_get(char *url)
+{
+        struct reversepath *reverse = config.reversepath_list;
+
+        while (reverse) {
+                if (strstr(url, reverse->path) == url)
+                        return reverse;
+
+                reverse = reverse->next;
+        }
+
+        return NULL;
+}
+
+/*
+ * Rewrite the URL for reverse proxying.
+ */
+char *
+reverse_rewrite_url(struct conn_s *connptr, hashmap_t hashofheaders, char *url)
+{
+        char *rewrite_url = NULL;
+        char *cookie = NULL;
+        char *cookieval;
+        struct reversepath *reverse;
+
+        /* Reverse requests always start with a slash */
+        if (*url == '/') {
+                /* First try locating the reverse mapping by request url */
+                reverse = reversepath_get(url);
+                if (reverse) {
+                        rewrite_url = safemalloc(strlen(url) +
+                                                 strlen(reverse->url) + 1);
+                        strcpy(rewrite_url, reverse->url);
+                        strcat(rewrite_url, url + strlen(reverse->path));
+                } else if (config.reversemagic
+                           && hashmap_entry_by_key(hashofheaders,
+                                                   "cookie",
+                                                   (void **)&cookie) > 0) {
+
+                        /* No match - try the magical tracking cookie next */
+                        if ((cookieval = strstr(cookie, REVERSE_COOKIE "="))
+                            && (reverse =
+                                reversepath_get(cookieval +
+                                                strlen(REVERSE_COOKIE) + 1))) {
+
+                                rewrite_url = safemalloc(strlen(url) +
+                                                         strlen
+                                                         (reverse->url) + 1);
+                                strcpy(rewrite_url, reverse->url);
+                                strcat(rewrite_url, url + 1);
+
+                                log_message(LOG_INFO,
+                                            "Magical tracking cookie says: %s",
+                                            reverse->path);
+                        }
+                }
+        }
+
+        /* Forward proxy support off and no reverse path match found */
+        if (config.reverseonly && !rewrite_url) {
+                log_message(LOG_ERR, "Bad request");
+                indicate_http_error(connptr, 400, "Bad Request",
+                                    "detail",
+                                    "Request has an invalid URL", "url",
+                                    url, NULL);
+                return NULL;
+        }
+
+        log_message(LOG_CONN, "Rewriting URL: %s -> %s", url, rewrite_url);
+
+        /* Store reverse path so that the magical tracking cookie can be set */
+        if (config.reversemagic)
+                connptr->reversepath = safestrdup(reverse->path);
+
+        return rewrite_url;
+}
-- 
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