Move uri_parser to lib

2 files changed, 364 insertions, 0 deletions

diff --git a/src/core/lib/uri/uri_parser.cc b/src/core/lib/uri/uri_parser.cc
new file mode 100644
index 0000000000..f212c7d2c0
--- /dev/null
+++ b/src/core/lib/uri/uri_parser.cc
@@ -0,0 +1,314 @@
+/*
+ *
+ * Copyright 2015 gRPC 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
+ *
+ *     http://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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/uri/uri_parser.h"
+
+#include <string.h>
+
+#include <grpc/slice_buffer.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/slice/percent_encoding.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
+
+/** a size_t default value... maps to all 1's */
+#define NOT_SET (~(size_t)0)
+
+static grpc_uri* bad_uri(const char* uri_text, size_t pos, const char* section,
+                         bool suppress_errors) {
+  char* line_prefix;
+  size_t pfx_len;
+
+  if (!suppress_errors) {
+    gpr_asprintf(&line_prefix, "bad uri.%s: '", section);
+    pfx_len = strlen(line_prefix) + pos;
+    gpr_log(GPR_ERROR, "%s%s'", line_prefix, uri_text);
+    gpr_free(line_prefix);
+
+    line_prefix = static_cast<char*>(gpr_malloc(pfx_len + 1));
+    memset(line_prefix, ' ', pfx_len);
+    line_prefix[pfx_len] = 0;
+    gpr_log(GPR_ERROR, "%s^ here", line_prefix);
+    gpr_free(line_prefix);
+  }
+
+  return nullptr;
+}
+
+/** Returns a copy of percent decoded \a src[begin, end) */
+static char* decode_and_copy_component(const char* src, size_t begin,
+                                       size_t end) {
+  grpc_slice component =
+      (begin == NOT_SET || end == NOT_SET)
+          ? grpc_empty_slice()
+          : grpc_slice_from_copied_buffer(src + begin, end - begin);
+  grpc_slice decoded_component =
+      grpc_permissive_percent_decode_slice(component);
+  char* out = grpc_dump_slice(decoded_component, GPR_DUMP_ASCII);
+  grpc_slice_unref_internal(component);
+  grpc_slice_unref_internal(decoded_component);
+  return out;
+}
+
+static bool valid_hex(char c) {
+  return ((c >= 'a') && (c <= 'f')) || ((c >= 'A') && (c <= 'F')) ||
+         ((c >= '0') && (c <= '9'));
+}
+
+/** Returns how many chars to advance if \a uri_text[i] begins a valid \a pchar
+ * production. If \a uri_text[i] introduces an invalid \a pchar (such as percent
+ * sign not followed by two hex digits), NOT_SET is returned. */
+static size_t parse_pchar(const char* uri_text, size_t i) {
+  /* pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
+   * unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
+   * pct-encoded = "%" HEXDIG HEXDIG
+   * sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
+   / "*" / "+" / "," / ";" / "=" */
+  char c = uri_text[i];
+  switch (c) {
+    default:
+      if (((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z')) ||
+          ((c >= '0') && (c <= '9'))) {
+        return 1;
+      }
+      break;
+    case ':':
+    case '@':
+    case '-':
+    case '.':
+    case '_':
+    case '~':
+    case '!':
+    case '$':
+    case '&':
+    case '\'':
+    case '(':
+    case ')':
+    case '*':
+    case '+':
+    case ',':
+    case ';':
+    case '=':
+      return 1;
+    case '%': /* pct-encoded */
+      if (valid_hex(uri_text[i + 1]) && valid_hex(uri_text[i + 2])) {
+        return 2;
+      }
+      return NOT_SET;
+  }
+  return 0;
+}
+
+/* *( pchar / "?" / "/" ) */
+static int parse_fragment_or_query(const char* uri_text, size_t* i) {
+  char c;
+  while ((c = uri_text[*i]) != 0) {
+    const size_t advance = parse_pchar(uri_text, *i); /* pchar */
+    switch (advance) {
+      case 0: /* uri_text[i] isn't in pchar */
+        /* maybe it's ? or / */
+        if (uri_text[*i] == '?' || uri_text[*i] == '/') {
+          (*i)++;
+          break;
+        } else {
+          return 1;
+        }
+        GPR_UNREACHABLE_CODE(return 0);
+      default:
+        (*i) += advance;
+        break;
+      case NOT_SET: /* uri_text[i] introduces an invalid URI */
+        return 0;
+    }
+  }
+  /* *i is the first uri_text position past the \a query production, maybe \0 */
+  return 1;
+}
+
+static void parse_query_parts(grpc_uri* uri) {
+  static const char* QUERY_PARTS_SEPARATOR = "&";
+  static const char* QUERY_PARTS_VALUE_SEPARATOR = "=";
+  GPR_ASSERT(uri->query != nullptr);
+  if (uri->query[0] == '\0') {
+    uri->query_parts = nullptr;
+    uri->query_parts_values = nullptr;
+    uri->num_query_parts = 0;
+    return;
+  }
+
+  gpr_string_split(uri->query, QUERY_PARTS_SEPARATOR, &uri->query_parts,
+                   &uri->num_query_parts);
+  uri->query_parts_values =
+      static_cast<char**>(gpr_malloc(uri->num_query_parts * sizeof(char**)));
+  for (size_t i = 0; i < uri->num_query_parts; i++) {
+    char** query_param_parts;
+    size_t num_query_param_parts;
+    char* full = uri->query_parts[i];
+    gpr_string_split(full, QUERY_PARTS_VALUE_SEPARATOR, &query_param_parts,
+                     &num_query_param_parts);
+    GPR_ASSERT(num_query_param_parts > 0);
+    uri->query_parts[i] = query_param_parts[0];
+    if (num_query_param_parts > 1) {
+      /* TODO(dgq): only the first value after the separator is considered.
+       * Perhaps all chars after the first separator for the query part should
+       * be included, even if they include the separator. */
+      uri->query_parts_values[i] = query_param_parts[1];
+    } else {
+      uri->query_parts_values[i] = nullptr;
+    }
+    for (size_t j = 2; j < num_query_param_parts; j++) {
+      gpr_free(query_param_parts[j]);
+    }
+    gpr_free(query_param_parts);
+    gpr_free(full);
+  }
+}
+
+grpc_uri* grpc_uri_parse(const char* uri_text, bool suppress_errors) {
+  grpc_uri* uri;
+  size_t scheme_begin = 0;
+  size_t scheme_end = NOT_SET;
+  size_t authority_begin = NOT_SET;
+  size_t authority_end = NOT_SET;
+  size_t path_begin = NOT_SET;
+  size_t path_end = NOT_SET;
+  size_t query_begin = NOT_SET;
+  size_t query_end = NOT_SET;
+  size_t fragment_begin = NOT_SET;
+  size_t fragment_end = NOT_SET;
+  size_t i;
+
+  for (i = scheme_begin; uri_text[i] != 0; i++) {
+    if (uri_text[i] == ':') {
+      scheme_end = i;
+      break;
+    }
+    if (uri_text[i] >= 'a' && uri_text[i] <= 'z') continue;
+    if (uri_text[i] >= 'A' && uri_text[i] <= 'Z') continue;
+    if (i != scheme_begin) {
+      if (uri_text[i] >= '0' && uri_text[i] <= '9') continue;
+      if (uri_text[i] == '+') continue;
+      if (uri_text[i] == '-') continue;
+      if (uri_text[i] == '.') continue;
+    }
+    break;
+  }
+  if (scheme_end == NOT_SET) {
+    return bad_uri(uri_text, i, "scheme", suppress_errors);
+  }
+
+  if (uri_text[scheme_end + 1] == '/' && uri_text[scheme_end + 2] == '/') {
+    authority_begin = scheme_end + 3;
+    for (i = authority_begin; uri_text[i] != 0 && authority_end == NOT_SET;
+         i++) {
+      if (uri_text[i] == '/' || uri_text[i] == '?' || uri_text[i] == '#') {
+        authority_end = i;
+      }
+    }
+    if (authority_end == NOT_SET && uri_text[i] == 0) {
+      authority_end = i;
+    }
+    if (authority_end == NOT_SET) {
+      return bad_uri(uri_text, i, "authority", suppress_errors);
+    }
+    /* TODO(ctiller): parse the authority correctly */
+    path_begin = authority_end;
+  } else {
+    path_begin = scheme_end + 1;
+  }
+
+  for (i = path_begin; uri_text[i] != 0; i++) {
+    if (uri_text[i] == '?' || uri_text[i] == '#') {
+      path_end = i;
+      break;
+    }
+  }
+  if (path_end == NOT_SET && uri_text[i] == 0) {
+    path_end = i;
+  }
+  if (path_end == NOT_SET) {
+    return bad_uri(uri_text, i, "path", suppress_errors);
+  }
+
+  if (uri_text[i] == '?') {
+    query_begin = ++i;
+    if (!parse_fragment_or_query(uri_text, &i)) {
+      return bad_uri(uri_text, i, "query", suppress_errors);
+    } else if (uri_text[i] != 0 && uri_text[i] != '#') {
+      /* We must be at the end or at the beginning of a fragment */
+      return bad_uri(uri_text, i, "query", suppress_errors);
+    }
+    query_end = i;
+  }
+  if (uri_text[i] == '#') {
+    fragment_begin = ++i;
+    if (!parse_fragment_or_query(uri_text, &i)) {
+      return bad_uri(uri_text, i - fragment_end, "fragment", suppress_errors);
+    } else if (uri_text[i] != 0) {
+      /* We must be at the end */
+      return bad_uri(uri_text, i, "fragment", suppress_errors);
+    }
+    fragment_end = i;
+  }
+
+  uri = static_cast<grpc_uri*>(gpr_zalloc(sizeof(*uri)));
+  uri->scheme = decode_and_copy_component(uri_text, scheme_begin, scheme_end);
+  uri->authority =
+      decode_and_copy_component(uri_text, authority_begin, authority_end);
+  uri->path = decode_and_copy_component(uri_text, path_begin, path_end);
+  uri->query = decode_and_copy_component(uri_text, query_begin, query_end);
+  uri->fragment =
+      decode_and_copy_component(uri_text, fragment_begin, fragment_end);
+  parse_query_parts(uri);
+
+  return uri;
+}
+
+const char* grpc_uri_get_query_arg(const grpc_uri* uri, const char* key) {
+  GPR_ASSERT(key != nullptr);
+  if (key[0] == '\0') return nullptr;
+
+  for (size_t i = 0; i < uri->num_query_parts; ++i) {
+    if (0 == strcmp(key, uri->query_parts[i])) {
+      return uri->query_parts_values[i];
+    }
+  }
+  return nullptr;
+}
+
+void grpc_uri_destroy(grpc_uri* uri) {
+  if (!uri) return;
+  gpr_free(uri->scheme);
+  gpr_free(uri->authority);
+  gpr_free(uri->path);
+  gpr_free(uri->query);
+  for (size_t i = 0; i < uri->num_query_parts; ++i) {
+    gpr_free(uri->query_parts[i]);
+    gpr_free(uri->query_parts_values[i]);
+  }
+  gpr_free(uri->query_parts);
+  gpr_free(uri->query_parts_values);
+  gpr_free(uri->fragment);
+  gpr_free(uri);
+}
diff --git a/src/core/lib/uri/uri_parser.h b/src/core/lib/uri/uri_parser.h
new file mode 100644
index 0000000000..c13778bc55
--- /dev/null
+++ b/src/core/lib/uri/uri_parser.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015 gRPC 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
+ *
+ *     http://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.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_URI_URI_PARSER_H
+#define GRPC_CORE_EXT_URI_URI_PARSER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stddef.h>
+
+typedef struct {
+  char* scheme;
+  char* authority;
+  char* path;
+  char* query;
+  /** Query substrings separated by '&' */
+  char** query_parts;
+  /** Number of elements in \a query_parts and \a query_parts_values */
+  size_t num_query_parts;
+  /** Split each query part by '='. NULL if not present. */
+  char** query_parts_values;
+  char* fragment;
+} grpc_uri;
+
+/** parse a uri, return NULL on failure */
+grpc_uri* grpc_uri_parse(const char* uri_text, bool suppress_errors);
+
+/** return the part of a query string after the '=' in "?key=xxx&...", or NULL
+ * if key is not present */
+const char* grpc_uri_get_query_arg(const grpc_uri* uri, const char* key);
+
+/** destroy a uri */
+void grpc_uri_destroy(grpc_uri* uri);
+
+#endif /* GRPC_CORE_EXT_URI_URI_PARSER_H */