chore: import upstream snapshot with attribution

2026-07-13 12:25:30 +08:00
commit 680845cb1c
445 changed files with 103779 additions and 0 deletions
@@ -0,0 +1,140 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2025-2026 Apple Inc. and the Containerization project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+/// Static table lookups for a container. The values will be used to
+/// construct /etc/hosts for a given container.
+public struct Hosts: Sendable {
+    /// Represents one entry in an /etc/hosts file.
+    public struct Entry: Sendable {
+        /// The IPV4 or IPV6 address in String form.
+        public var ipAddress: String
+        /// The hostname(s) for the entry.
+        public var hostnames: [String]
+        /// An optional comment to be placed to the right side of the entry.
+        public var comment: String?
+
+        public init(ipAddress: String, hostnames: [String], comment: String? = nil) {
+            self.comment = comment
+            self.hostnames = hostnames
+            self.ipAddress = ipAddress
+        }
+
+        /// The information in the structure rendered to a String representation
+        /// that matches the format /etc/hosts expects.
+        public var rendered: String {
+            var line = ipAddress
+            if !hostnames.isEmpty {
+                line += " " + hostnames.joined(separator: " ")
+            }
+            if let comment {
+                line += " # \(comment) "
+            }
+            return line
+        }
+
+        public static func localHostIPV4(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "127.0.0.1",
+                hostnames: ["localhost"],
+                comment: comment
+            )
+        }
+
+        public static func localHostIPV6(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "::1",
+                hostnames: ["localhost", "ip6-localhost", "ip6-loopback"],
+                comment: comment
+            )
+        }
+
+        public static func ipv6LocalNet(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "fe00::",
+                hostnames: ["ip6-localnet"],
+                comment: comment
+            )
+        }
+
+        public static func ipv6MulticastPrefix(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "ff00::",
+                hostnames: ["ip6-mcastprefix"],
+                comment: comment
+            )
+        }
+
+        public static func ipv6AllNodes(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "ff02::1",
+                hostnames: ["ip6-allnodes"],
+                comment: comment
+            )
+        }
+
+        public static func ipv6AllRouters(comment: String? = nil) -> Self {
+            Self(
+                ipAddress: "ff02::2",
+                hostnames: ["ip6-allrouters"],
+                comment: comment
+            )
+        }
+    }
+
+    /// The entries to be written to /etc/hosts.
+    public var entries: [Entry]
+
+    /// A comment to render at the top of the file.
+    public var comment: String?
+
+    public init(
+        entries: [Entry],
+        comment: String? = nil
+    ) {
+        self.entries = entries
+        self.comment = comment
+    }
+}
+
+extension Hosts {
+    /// A default entry that can be used for convenience. It contains a IPV4
+    /// and IPV6 localhost entry, as well as ipv6 localnet, ipv6 mcastprefix,
+    /// ipv6 allnodes, and ipv6 allrouters.
+    public static let `default` = Hosts(entries: [
+        Entry.localHostIPV4(),
+        Entry.localHostIPV6(),
+        Entry.ipv6LocalNet(),
+        Entry.ipv6MulticastPrefix(),
+        Entry.ipv6AllNodes(),
+        Entry.ipv6AllRouters(),
+    ])
+
+    /// Returns a string variant of the data that can be written to
+    /// /etc/hosts directly.
+    public var hostsFile: String {
+        var lines: [String] = []
+
+        if let comment {
+            lines.append("# \(comment)")
+        }
+
+        for entry in entries {
+            lines.append(entry.rendered)
+        }
+
+        return lines.joined(separator: "\n") + "\n"
+    }
+}