Move is ipv4/ipv6 functions from Aws-c-sdkutils to Aws-c-common

include/aws/common/host_utils.h

@@ -0,0 +1,28 @@
+#ifndef AWS_COMMON_HOST_UTILS_H
+#define AWS_COMMON_HOST_UTILS_H
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#include <aws/common/common.h>
+
+struct aws_byte_cursor;
+
+AWS_PUSH_SANE_WARNING_LEVEL
+AWS_EXTERN_C_BEGIN
+
+/*
+ * Determine whether host cursor is IPv4 string.
+ */
+AWS_COMMON_API bool aws_is_ipv4(struct aws_byte_cursor host);
+
+/*
+ * Determine whether host cursor is IPv6 string.
+ * Supports checking for uri encoded strings and scoped literals.
+ */
+AWS_COMMON_API bool aws_is_ipv6(struct aws_byte_cursor host, bool is_uri_encoded);
+
+AWS_EXTERN_C_END
+AWS_POP_SANE_WARNING_LEVEL
+
+#endif /* AWS_COMMON_HOST_UTILS_H */

source/host_utils.c

@@ -0,0 +1,127 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#include <aws/common/host_utils.h>
+#include <aws/common/string.h>
+#include <inttypes.h>
+
+#ifdef _MSC_VER /* Disable sscanf warnings on windows. */
+#    pragma warning(disable : 4204)
+#    pragma warning(disable : 4706)
+#    pragma warning(disable : 4996)
+#endif
+
+/* 4 octets of 3 chars max + 3 separators + null terminator */
+#define AWS_IPV4_STR_LEN 16
+#define IP_CHAR_FMT "%03" SCNu16
+
+static bool s_is_ipv6_char(uint8_t value) {
+    return aws_isxdigit(value) || value == ':';
+}
+
+static bool s_starts_with(struct aws_byte_cursor cur, uint8_t ch) {
+    return cur.len > 0 && cur.ptr[0] == ch;
+}
+
+static bool s_ends_with(struct aws_byte_cursor cur, uint8_t ch) {
+    return cur.len > 0 && cur.ptr[cur.len - 1] == ch;
+}
+
+bool aws_is_ipv4(struct aws_byte_cursor host) {
+    if (host.len > AWS_IPV4_STR_LEN - 1) {
+        return false;
+    }
+
+    char copy[AWS_IPV4_STR_LEN] = {0};
+    memcpy(copy, host.ptr, host.len);
+
+    uint16_t octet[4] = {0};
+    char remainder[2] = {0};
+    if (4 != sscanf(
+                 copy,
+                 IP_CHAR_FMT "." IP_CHAR_FMT "." IP_CHAR_FMT "." IP_CHAR_FMT "%1s",
+                 &octet[0],
+                 &octet[1],
+                 &octet[2],
+                 &octet[3],
+                 remainder)) {
+        return false;
+    }
+
+    for (size_t i = 0; i < 4; ++i) {
+        if (octet[i] > 255) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+/* actual encoding is %25, but % is omitted for simplicity, since split removes it */
+static struct aws_byte_cursor s_percent_uri_enc = AWS_BYTE_CUR_INIT_FROM_STRING_LITERAL("25");
+/*
+ * IPv6 format:
+ * 8 groups of 4 hex chars separated by colons (:)
+ * leading 0s in each group can be skipped
+ * 2 or more consecutive zero groups can be replaced by double colon (::),
+ *     but only once.
+ * ipv6 literal can be scoped by to zone by appending % followed by zone name
+ * ( does not look like there is length reqs on zone name length. this
+ * implementation enforces that its > 1 )
+ * ipv6 can be embedded in url, in which case it must be wrapped inside []
+ * and % be uri encoded as %25.
+ * Implementation is fairly trivial and just iterates through the string
+ * keeping track of the spec above.
+ */
+bool aws_is_ipv6(struct aws_byte_cursor host, bool is_uri_encoded) {
+    if (host.len == 0) {
+        return false;
+    }
+
+    if (is_uri_encoded) {
+        if (!s_starts_with(host, '[') || !s_ends_with(host, ']')) {
+            return false;
+        }
+        aws_byte_cursor_advance(&host, 1);
+        --host.len;
+    }
+
+    struct aws_byte_cursor substr = {0};
+    /* first split is required ipv6 part */
+    bool is_split = aws_byte_cursor_next_split(&host, '%', &substr);
+    AWS_ASSERT(is_split); /* function is guaranteed to return at least one split */
+
+    if (!is_split || substr.len == 0 || s_ends_with(substr, ':') ||
+        !aws_byte_cursor_satisfies_pred(&substr, s_is_ipv6_char)) {
+        return false;
+    }
+
+    uint8_t group_count = 0;
+    bool has_double_colon = false;
+    struct aws_byte_cursor group = {0};
+    while (aws_byte_cursor_next_split(&substr, ':', &group)) {
+        ++group_count;
+
+        if (group_count > 8 ||                                         /* too many groups */
+            group.len > 4 ||                                           /* too many chars in group */
+            (has_double_colon && group.len == 0 && group_count > 2)) { /* only one double colon allowed */
+            return false;
+        }
+
+        has_double_colon = has_double_colon || group.len == 0;
+    }
+
+    /* second split is optional zone part */
+    if (aws_byte_cursor_next_split(&host, '%', &substr)) {
+        if ((is_uri_encoded &&
+             (substr.len < 3 ||
+              !aws_byte_cursor_starts_with(&substr, &s_percent_uri_enc))) || /* encoding for % + 1 extra char */
+            (!is_uri_encoded && substr.len == 0) ||                          /* at least 1 char */
+            !aws_byte_cursor_satisfies_pred(&substr, aws_isalnum)) {
+            return false;
+        }
+    }
+
+    return has_double_colon ? group_count < 7 : group_count == 8;
+}

tests/CMakeLists.txt

@@ -528,6 +528,8 @@ add_test_case(test_cross_process_lock_works_cross_proc)
 add_test_case(cross_process_lock_mp_test_runner)
 add_test_case(test_cross_process_lock_invalid_nonce_fails)
 
+add_test_case(host_util_is_ipv4)
+add_test_case(host_util_is_ipv6)
 
 generate_test_driver(${PROJECT_NAME}-tests)
 

tests/host_util_test.c

@@ -0,0 +1,68 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+#include <aws/common/byte_buf.h>
+#include <aws/common/host_utils.h>
+#include <aws/testing/aws_test_harness.h>
+
+AWS_TEST_CASE(host_util_is_ipv4, s_test_is_ipv4)
+static int s_test_is_ipv4(struct aws_allocator *allocator, void *ctx) {
+    (void)allocator;
+    (void)ctx;
+
+    ASSERT_TRUE(aws_is_ipv4(aws_byte_cursor_from_c_str("0.0.0.0")));
+    ASSERT_TRUE(aws_is_ipv4(aws_byte_cursor_from_c_str("127.0.0.1")));
+    ASSERT_TRUE(aws_is_ipv4(aws_byte_cursor_from_c_str("255.255.255.255")));
+    ASSERT_TRUE(aws_is_ipv4(aws_byte_cursor_from_c_str("192.168.1.1")));
+
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("256.0.0.1")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("127.0.0")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("127.0")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("127")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("")));
+
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("foo.com")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("a.b.c.d")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("a127.0.0.1")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("127.0.0.1a")));
+    ASSERT_FALSE(aws_is_ipv4(aws_byte_cursor_from_c_str("127.0.0.1011")));
+
+    return AWS_OP_SUCCESS;
+}
+
+AWS_TEST_CASE(host_util_is_ipv6, s_test_is_ipv6)
+static int s_test_is_ipv6(struct aws_allocator *allocator, void *ctx) {
+    (void)allocator;
+    (void)ctx;
+
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("0:0:0000:0000:0000:0:0:0"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001:0db8:0000:0000:0000:8a2e:0370:7334"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001:0DB8:0000:0000:0000:8a2e:0370:7334"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("fe80::1"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("fe80::1%en0"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("::1"), false));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("[2001:0db8:0000:0000:0000:8a2e:0370:7334]"), true));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1]"), true));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1%25en0]"), true));
+    ASSERT_TRUE(aws_is_ipv6(aws_byte_cursor_from_c_str("[2001:db8:85a3:8d3:1319:8a2e:370:7348]"), true));
+
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001:0db8:0000:0000:0000:8a2e:0370"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001:0db8:0000:0000:0000:8a2e:0370:"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001::"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("2001:0db8:0000:0000:0000:8a2e:0370:7334:8745"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str(":2001:0db8:0000:0000:0000:8a2e:0370:7334:8745"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("z001:0db8:0000:0000:0000:8a2e:0370:7334:8745"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("z001::8a2e::8745"), false));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("::2001:0db8:0000:0000:8a2e:0370:7334"), false));
+
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("fe80::1%25en0"), true));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1%en0]"), true));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1%24en0]"), true));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1%25en0"), true));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("fe80::1%25en0]"), true));
+    ASSERT_FALSE(aws_is_ipv6(aws_byte_cursor_from_c_str("[fe80::1%25]"), true));
+
+    return AWS_OP_SUCCESS;
+}