Use hosts-replaced URL only when loading resources

components/net_traits/hosts.rs

@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::collections::HashMap;
+use std::env;
+use std::fs::File;
+use std::io::{BufReader, Read};
+use url::Url;
+
+use {IPV4_REGEX, IPV6_REGEX};
+
+static mut HOST_TABLE: Option<*mut HashMap<String, String>> = None;
+
+
+pub fn global_init() {
+    //TODO: handle bad file path
+    let path = match env::var("HOST_FILE") {
+        Ok(host_file_path) => host_file_path,
+        Err(_) => return,
+    };
+
+    let mut file = match File::open(&path) {
+        Ok(f) => BufReader::new(f),
+        Err(_) => return,
+    };
+
+    let mut lines = String::new();
+    match file.read_to_string(&mut lines) {
+        Ok(_) => (),
+        Err(_) => return,
+    };
+
+    unsafe {
+        let host_table = Box::into_raw(parse_hostsfile(&lines));
+        HOST_TABLE = Some(host_table);
+    }
+}
+
+pub fn parse_hostsfile(hostsfile_content: &str) -> Box<HashMap<String, String>> {
+    let mut host_table = HashMap::new();
+    let lines: Vec<&str> = hostsfile_content.split('\n').collect();
+
+    for line in lines.iter() {
+        let ip_host: Vec<&str> = line.trim().split(|c: char| c == ' ' || c == '\t').collect();
+        if ip_host.len() > 1 {
+            if !IPV4_REGEX.is_match(ip_host[0]) && !IPV6_REGEX.is_match(ip_host[0]) { continue; }
+            let address = ip_host[0].to_owned();
+
+            for token in ip_host.iter().skip(1) {
+                if token.as_bytes()[0] == b'#' {
+                    break;
+                }
+                host_table.insert(token.to_owned().to_string(), address.clone());
+            }
+        }
+    }
+    box host_table
+}
+
+pub fn replace_hosts(url: &Url) -> Url {
+    unsafe {
+        HOST_TABLE.map(|host_table| {
+            host_replacement(host_table, url)
+        }).unwrap_or_else(|| url.clone())
+    }
+}
+
+pub fn host_replacement(host_table: *mut HashMap<String, String>,
+                        url: &Url) -> Url {
+    unsafe {
+        url.domain().and_then(|domain|
+                              (*host_table).get(domain).map(|ip| {
+                                  let mut net_url = url.clone();
+                                  *net_url.domain_mut().unwrap() = ip.clone();
+                                  net_url
+                              })).unwrap_or(url.clone())
+    }
+}