Create EN-US version of routing.md

Author: oweid

docs/en_US/config/routing.md

@@ -1,3 +1,268 @@
 # Routing
 
-The documentation for this page is missing. Please submit a [pull request](https://github.com/v2fly/v2fly-github-io/pulls) or refer to the Chinese documentation.
+V2Ray has a built-in routing module that can distribute inbound data through different outbound connections based on requirements, enabling selective proxy routing. A common use case is to split domestic and international traffic. V2Ray can internally determine traffic from different countries or regions and route them to different outbound proxies.
+
+## RoutingObject
+
+`RoutingObject` corresponds to the `routing` entry in the configuration file.
+
+```json
+{
+    "domainStrategy": "AsIs",
+    "domainMatcher": "mph",
+    "rules": [],
+    "balancers": []
+}
+```
+
+> `domainStrategy`: "AsIs" | "IPIfNonMatch" | "IPOnDemand"
+
+Domain name resolution strategy:
+
+* `AsIs`: Uses only domain names for routing selection (default value)
+* `IPIfNonMatch`: Resolves domain names to IP addresses (A or AAAA records) for IP-based rule matching when no domain-based rules match
+  * When a domain has multiple IP addresses, all addresses are tried until one matches an IP rule
+  * The resolved IP is only used for routing selection; the original domain name is still used in forwarded packets
+* `IPOnDemand`: Immediately resolves domain names to IP addresses when encountering any IP-based rules during matching
+
+> `domainMatcher`: "linear" | "mph"
+
+Selects the domain matching algorithm:
+
+* `linear`: Uses linear matching algorithm (default value)
+* `mph`: Uses minimal perfect hash algorithm (v4.36.1+)
+  * With test data of about 170,000 entries, matching speed improves by ~30% and memory usage reduces by ~15%
+
+> `rules`: \[[RuleObject](#ruleobject)\]
+
+An array where each item is a rule. For each connection, routing will evaluate these rules in sequence. When a rule takes effect, the connection is forwarded to its specified `outboundTag` (or `balancerTag`, V2Ray 4.4+). When no rules match, traffic is forwarded to the first `outbound` by default.
+
+> `balancers`: \[ [BalancerObject](#balancerobject) \]
+
+(V2Ray 4.4+) An array where each item is a load balancer configuration. When a rule points to a load balancer, V2Ray selects an `outbound` through this load balancer to forward traffic.
+
+## RuleObject
+
+```json
+{
+    "domainMatcher": "mph",
+    "type": "field",
+    "domains": [
+        "baidu.com",
+        "qq.com",
+        "geosite:cn",
+        "ext:customizedGeoSiteFile.dat:cn"
+    ],
+    "ip": [
+        "0.0.0.0/8",
+        "10.0.0.0/8",
+        "fc00::/7",
+        "fe80::/10",
+        "geoip:cn",
+        "geoip:!cn",
+        "ext:customizedGeoIPFile.dat:cn",
+        "ext:customizedGeoIPFile.dat:!cn",
+        "ext-ip:customizedGeoIPFile.dat:cn",
+        "ext-ip:customizedGeoIPFile.dat:!cn"
+    ],
+    "port": "53,443,1000-2000",
+    "sourcePort": "53,443,1000-2000",
+    "network": "tcp",
+    "source": [
+        "10.0.0.1"
+    ],
+    "user": [
+        "[email protected]"
+    ],
+    "inboundTag": [
+        "tag-vmess"
+    ],
+    "protocol": [
+        "http",
+        "tls",
+        "bittorrent"
+    ],
+    "attrs": "attrs[':method'] == 'GET'",
+    "outboundTag": "direct",
+    "balancerTag": "balancer"
+}
+```
+
+:::tip
+When multiple attributes are specified, they must all be satisfied for the current rule to take effect. This means `domains` and `ip` rules should be used separately.
+:::
+
+> `domainMatcher`: "linear" | "mph"
+
+Selects the domain matching algorithm. The `domainMatcher` here takes precedence over the one configured in `RoutingObject`.
+
+* `linear`: Uses linear matching algorithm (default value)
+* `mph`: Uses minimal perfect hash algorithm (v4.36.1+)
+  * With test data of about 170,000 entries, matching speed improves by ~30% and memory usage reduces by ~15%
+
+> `type`: "field"
+
+Currently only supports the "field" option.
+
+> `domains`: \[string\]
+
+An array where each item is a domain match. Several formats are supported:
+
+* **Plain string**: Rule takes effect when this string matches any part of the target domain. For example, `sina.com` matches `sina.com`, `sina.com.cn`, `sina.company`, and `www.sina.com`, but not `sina.cn`.
+* **Regular expression**: Starts with `regexp:`, followed by a regular expression. Rule takes effect when this regex matches the target domain. For example, `regexp:\.goo.*\.com$` matches `www.google.com`, `fonts.googleapis.com`, but not `google.com`.
+* **Subdomain (recommended)**: Starts with `domain:`, followed by a domain name. Rule takes effect when this domain or its subdomains match the target domain. For example, `domain:v2ray.com` matches `www.v2ray.com`, `v2ray.com`, but not `xv2ray.com`.
+* **Full match**: Starts with `full:`, followed by a domain name. Rule takes effect when this domain exactly matches the target domain. For example, `full:v2ray.com` matches `v2ray.com` but not `www.v2ray.com`.
+* **Predefined domain list**: Starts with `geosite:`, followed by a category name, such as `geosite:google` or `geosite:cn`. See [Predefined Domain Lists](#predefined-domain-lists) for details.
+* **Load from file**: Format is `ext:file:tag`, must start with `ext:`, followed by filename and tag. File should be placed in the [resource directory](env.md#resource-file-path), format same as `geosite.dat`, and tag must exist in the file.
+
+> `ip`: \[string\]
+
+An array where each item represents an IP range. Rule takes effect when any item matches the target IP. Several formats are supported:
+
+* IP: Like `127.0.0.1`
+* [CIDR](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing): Like `10.0.0.0/8`
+* GeoIP:
+  * Format `geoip:cn` for positive match, matches "Mainland China IP addresses". Uses two-letter [country/region codes](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2).
+  * Format `geoip:!cn` for negative match, matches "non-Mainland China IP addresses".
+  * Special value: `geoip:private` (V2Ray 3.5+) includes all private addresses like `127.0.0.1`
+* Load from file:
+  * Format `ext:file:tag` or `ext-ip:file:tag` for positive match
+  * Format `ext:file:!tag` or `ext-ip:file:!tag` for negative match
+  * Must start with `ext:` or `ext-ip:`, followed by filename and tag/!tag
+
+:::tip
+`ext:geoip.dat:cn` and `ext-ip:geoip.dat:cn` are equivalent to `geoip:cn`
+
+`ext:geoip.dat:!cn` and `ext-ip:geoip.dat:!cn` are equivalent to `geoip:!cn`
+:::
+
+> `port`: number | string
+
+Target port range, three formats:
+
+* `a-b`: a and b are positive integers less than 65536. Rule applies to ports in this inclusive range.
+* `a`: a is a positive integer less than 65536. Rule applies when target port equals a.
+* (V2Ray 4.18+) Mix of above formats, separated by commas. Example: `53,443,1000-2000`
+
+> `sourcePort`: number | string
+
+Source port range, same format as above
+
+> `network`: "tcp" | "udp" | "tcp,udp"
+
+Available values are "tcp", "udp", or "tcp,udp". Rule takes effect when connection type matches.
+
+> `source`: \[string\]
+
+An array where each item represents an IP range. Formats include IP, CIDR, GeoIP, and loading from file. Rule takes effect when any item matches the source IP.
+
+> `user`: \[string\]
+
+An array where each item is an email address. Rule takes effect when any item matches the source user. Currently supported by Shadowsocks and VMess.
+
+> `inboundTag`: \[string\]
+
+An array where each item is an identifier. Rule takes effect when any item matches the inbound protocol identifier.
+
+> `protocol`: \[ "http" | "tls" | "bittorrent" \]
+
+An array where each item represents a protocol. Rule takes effect when any protocol matches the current connection's traffic. Requires `sniffing` option enabled in inbound proxy.
+
+> `attrs`: string
+
+(V2Ray 4.18+) A script to check traffic attributes. Rule takes effect when this script returns true.
+
+Uses [Starlark](https://github.com/bazelbuild/starlark) scripting language, which is a subset of Python. Script receives a global variable `attrs` containing traffic-related attributes.
+
+Currently only HTTP inbound proxy sets these attributes.
+
+Examples:
+
+* Detect HTTP GET: `attrs[':method'] == 'GET'`
+* Detect HTTP Path: `attrs[':path'].startswith('/test')`
+* Detect Content Type: `attrs['accept'].index('text/html') >= 0`
+
+> `outboundTag`: string
+
+Corresponds to an identifier of an additional [outbound connection configuration](outbounds.md#outboundobject).
+
+> `balancerTag`: string
+
+Corresponds to a load balancer identifier. Must choose either `balancerTag` or `outboundTag`. When both are specified, `outboundTag` takes effect.
+
+## BalancerObject
+
+Load balancer configuration. When a load balancer takes effect, it selects the most suitable outbound protocol from specified protocols according to configuration.
+
+```json
+{
+    "tag": "balancer",
+    "selector": [],
+    "strategy": {
+      "type": "random"
+    }
+}
+```
+
+> `tag`: string
+
+Identifier for this load balancer, used to match `balancerTag` in `RuleObject`.
+
+> `selector`: \[ string \]
+
+An array of strings, each used for prefix matching with outbound protocol identifiers. For outbound protocol identifiers `[ "a", "ab", "c", "ba" ]`, `"selector": ["a"]` would match `[ "a", "ab" ]`.
+
+> `strategy`: StrategyObject
+
+The strategy object for load balancing.
+
+## StrategyObject
+
+```json
+{
+    "type": "random"
+}
+```
+
+> `type`: string
+
+The type of load balancing strategy.
+
+Available types include `random` and `leastPing` (v4.38.0+).
+
+`random` randomly selects one outbound as the final outbound connection.
+
+`leastPing` selects the outbound connection with the fastest HTTPS GET request completion time based on observation records.
+
+Load balancing strategies depend on observation records from the outbound [connection observatory](observatory.md) component.
+
+## Predefined Domain Lists
+
+This list is maintained by the [domain-list-community](https://github.com/v2fly/domain-list-community) project and is pre-installed in every V2Ray package as `geosite.dat`. This file contains common domains, used as `geosite:listname`, like `geosite:google` for domains in the `google` file in the `data` directory of the `domain-list-community` project.
+
+:::tip
+If you encounter issues or find missing domains while using `geosite.dat`, feel free to submit an [issue](https://github.com/v2fly/domain-list-community/issues) or [pull request](https://github.com/v2fly/domain-list-community/pulls) to [v2fly/domain-list-community](https://github.com/v2fly/domain-list-community).
+:::
+
+Common domain categories include:
+
+* `category-ads`: Common advertising domains
+* `category-ads-all`: Common advertising domains plus ad provider domains
+* `tld-cn`: CNNIC-managed top-level domains for Mainland China (e.g., `.cn`, `.中国`)
+* `tld-!cn`: Non-Mainland China top-level domains (e.g., `.tw` for Taiwan, `.jp` for Japan, `.sg` for Singapore, `.us` for USA, `.ca` for Canada)
+* `geolocation-cn`: Common Mainland China website domains
+* `geolocation-!cn`: Common non-Mainland China website domains
+* `cn`: Combination of `geolocation-cn` and `tld-cn`
+* `apple`: Most Apple domains
+* `google`: Most Google domains
+* `microsoft`: Most Microsoft domains
+* `facebook`: Most Facebook domains
+* `twitter`: Most Twitter domains
+* `telegram`: Most Telegram domains
+* For more categories, see the [data directory](https://github.com/v2fly/domain-list-community/tree/master/data)
+
+## Geodata File Loader
+
+V2Ray includes multiple loaders for reading and decoding `geoip.dat` and `geosite.dat` files (v4.39.0+).
+
+This setting is controlled by the `v2ray.conf.geoloader` environment variable. See [Environment Variables](env.md#geodata-file-loader) for details.