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[PATCH v4 1/6] json: Import upstream jsmn-1.1.0


From: Patrick Steinhardt
Subject: [PATCH v4 1/6] json: Import upstream jsmn-1.1.0
Date: Mon, 18 Nov 2019 09:45:12 +0100

The upcoming support for LUKS2 encryption will require a JSON parser to
decode all parameters required for decryption of a drive. As there is
currently no other tool that requires JSON, and as gnulib does not
provide a parser, we need to introduce a new one into the code base. The
backend for the JSON implementation is going to be the jsmn library [1].
It has several benefits that make it a very good fit for inclusion in
GRUB:

    - It is licensed under MIT.
    - It is written in C89.
    - It has no dependencies, not even libc.
    - It is small with only about 500 lines of code.
    - It doesn't do any dynamic memory allocation.
    - It is testen on x86, amd64, ARM and AVR.

The library itself comes as a single header, only, that contains both
declarations and definitions. The exposed interface is kind of
simplistic, though, and does not provide any convenience features
whatsoever. Thus there will be a separate interface provided by GRUB
around this parser that is going to be implemented in the following
commit. This change only imports "jsmn.h" from tag v1.1.0 and adds it
unmodified to a new "json" module with the following command:

```
curl -L https://raw.githubusercontent.com/zserge/jsmn/v1.1.0/jsmn.h \
    -o grub-core/lib/json/jsmn.h
```

Upstream jsmn commit hash: fdcef3ebf886fa210d14956d3c068a653e76a24e
Upstream jsmn commit name: Modernize (#149), 2019-04-20

[1]: https://github.com/zserge/jsmn

Signed-off-by: Patrick Steinhardt <address@hidden>
Reviewed-by: Daniel Kiper <address@hidden>
---
 docs/grub-dev.texi          |  14 ++
 grub-core/Makefile.core.def |   5 +
 grub-core/lib/json/jsmn.h   | 468 ++++++++++++++++++++++++++++++++++++
 grub-core/lib/json/json.c   |  23 ++
 4 files changed, 510 insertions(+)
 create mode 100644 grub-core/lib/json/jsmn.h
 create mode 100644 grub-core/lib/json/json.c

diff --git a/docs/grub-dev.texi b/docs/grub-dev.texi
index ee389fd83..df2350be0 100644
--- a/docs/grub-dev.texi
+++ b/docs/grub-dev.texi
@@ -490,6 +490,7 @@ to update it.
 
 @menu
 * Gnulib::
+* jsmn::
 @end menu
 
 @node Gnulib
@@ -545,6 +546,19 @@ AC_SYS_LARGEFILE
 
 @end example
 
+@node jsmn
+@section jsmn
+
+jsmn is a minimalistic JSON parser which is implemented in a single header file
+@file{jsmn.h}. To import a different version of the jsmn parser, you may simply
+download the @file{jsmn.h} header from the desired tag or commit to the target
+directory:
+
+@example
+curl -L https://raw.githubusercontent.com/zserge/jsmn/v1.1.0/jsmn.h \
+    -o grub-core/lib/json/jsmn.h
+@end example
+
 @node Porting
 @chapter Porting
 
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 269370417..037de4023 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1176,6 +1176,11 @@ module = {
   common = disk/cryptodisk.c;
 };
 
+module = {
+  name = json;
+  common = lib/json/json.c;
+};
+
 module = {
   name = luks;
   common = disk/luks.c;
diff --git a/grub-core/lib/json/jsmn.h b/grub-core/lib/json/jsmn.h
new file mode 100644
index 000000000..b95368a20
--- /dev/null
+++ b/grub-core/lib/json/jsmn.h
@@ -0,0 +1,468 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2010 Serge Zaitsev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to 
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
THE
+ * SOFTWARE.
+ */
+#ifndef JSMN_H
+#define JSMN_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef JSMN_STATIC
+#define JSMN_API static
+#else
+#define JSMN_API extern
+#endif
+
+/**
+ * JSON type identifier. Basic types are:
+ *     o Object
+ *     o Array
+ *     o String
+ *     o Other primitive: number, boolean (true/false) or null
+ */
+typedef enum {
+  JSMN_UNDEFINED = 0,
+  JSMN_OBJECT = 1,
+  JSMN_ARRAY = 2,
+  JSMN_STRING = 3,
+  JSMN_PRIMITIVE = 4
+} jsmntype_t;
+
+enum jsmnerr {
+  /* Not enough tokens were provided */
+  JSMN_ERROR_NOMEM = -1,
+  /* Invalid character inside JSON string */
+  JSMN_ERROR_INVAL = -2,
+  /* The string is not a full JSON packet, more bytes expected */
+  JSMN_ERROR_PART = -3
+};
+
+/**
+ * JSON token description.
+ * type                type (object, array, string etc.)
+ * start       start position in JSON data string
+ * end         end position in JSON data string
+ */
+typedef struct {
+  jsmntype_t type;
+  int start;
+  int end;
+  int size;
+#ifdef JSMN_PARENT_LINKS
+  int parent;
+#endif
+} jsmntok_t;
+
+/**
+ * JSON parser. Contains an array of token blocks available. Also stores
+ * the string being parsed now and current position in that string.
+ */
+typedef struct {
+  unsigned int pos;     /* offset in the JSON string */
+  unsigned int toknext; /* next token to allocate */
+  int toksuper;         /* superior token node, e.g. parent object or array */
+} jsmn_parser;
+
+/**
+ * Create JSON parser over an array of tokens
+ */
+JSMN_API void jsmn_init(jsmn_parser *parser);
+
+/**
+ * Run JSON parser. It parses a JSON data string into and array of tokens, each
+ * describing
+ * a single JSON object.
+ */
+JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len,
+                        jsmntok_t *tokens, const unsigned int num_tokens);
+
+#ifndef JSMN_HEADER
+/**
+ * Allocates a fresh unused token from the token pool.
+ */
+static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, jsmntok_t *tokens,
+                                   const size_t num_tokens) {
+  jsmntok_t *tok;
+  if (parser->toknext >= num_tokens) {
+    return NULL;
+  }
+  tok = &tokens[parser->toknext++];
+  tok->start = tok->end = -1;
+  tok->size = 0;
+#ifdef JSMN_PARENT_LINKS
+  tok->parent = -1;
+#endif
+  return tok;
+}
+
+/**
+ * Fills token type and boundaries.
+ */
+static void jsmn_fill_token(jsmntok_t *token, const jsmntype_t type,
+                            const int start, const int end) {
+  token->type = type;
+  token->start = start;
+  token->end = end;
+  token->size = 0;
+}
+
+/**
+ * Fills next available token with JSON primitive.
+ */
+static int jsmn_parse_primitive(jsmn_parser *parser, const char *js,
+                                const size_t len, jsmntok_t *tokens,
+                                const size_t num_tokens) {
+  jsmntok_t *token;
+  int start;
+
+  start = parser->pos;
+
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    switch (js[parser->pos]) {
+#ifndef JSMN_STRICT
+    /* In strict mode primitive must be followed by "," or "}" or "]" */
+    case ':':
+#endif
+    case '\t':
+    case '\r':
+    case '\n':
+    case ' ':
+    case ',':
+    case ']':
+    case '}':
+      goto found;
+    }
+    if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
+      parser->pos = start;
+      return JSMN_ERROR_INVAL;
+    }
+  }
+#ifdef JSMN_STRICT
+  /* In strict mode primitive must be followed by a comma/object/array */
+  parser->pos = start;
+  return JSMN_ERROR_PART;
+#endif
+
+found:
+  if (tokens == NULL) {
+    parser->pos--;
+    return 0;
+  }
+  token = jsmn_alloc_token(parser, tokens, num_tokens);
+  if (token == NULL) {
+    parser->pos = start;
+    return JSMN_ERROR_NOMEM;
+  }
+  jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+  token->parent = parser->toksuper;
+#endif
+  parser->pos--;
+  return 0;
+}
+
+/**
+ * Fills next token with JSON string.
+ */
+static int jsmn_parse_string(jsmn_parser *parser, const char *js,
+                             const size_t len, jsmntok_t *tokens,
+                             const size_t num_tokens) {
+  jsmntok_t *token;
+
+  int start = parser->pos;
+
+  parser->pos++;
+
+  /* Skip starting quote */
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    char c = js[parser->pos];
+
+    /* Quote: end of string */
+    if (c == '\"') {
+      if (tokens == NULL) {
+        return 0;
+      }
+      token = jsmn_alloc_token(parser, tokens, num_tokens);
+      if (token == NULL) {
+        parser->pos = start;
+        return JSMN_ERROR_NOMEM;
+      }
+      jsmn_fill_token(token, JSMN_STRING, start + 1, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+      token->parent = parser->toksuper;
+#endif
+      return 0;
+    }
+
+    /* Backslash: Quoted symbol expected */
+    if (c == '\\' && parser->pos + 1 < len) {
+      int i;
+      parser->pos++;
+      switch (js[parser->pos]) {
+      /* Allowed escaped symbols */
+      case '\"':
+      case '/':
+      case '\\':
+      case 'b':
+      case 'f':
+      case 'r':
+      case 'n':
+      case 't':
+        break;
+      /* Allows escaped symbol \uXXXX */
+      case 'u':
+        parser->pos++;
+        for (i = 0; i < 4 && parser->pos < len && js[parser->pos] != '\0';
+             i++) {
+          /* If it isn't a hex character we have an error */
+          if (!((js[parser->pos] >= 48 && js[parser->pos] <= 57) ||   /* 0-9 */
+                (js[parser->pos] >= 65 && js[parser->pos] <= 70) ||   /* A-F */
+                (js[parser->pos] >= 97 && js[parser->pos] <= 102))) { /* a-f */
+            parser->pos = start;
+            return JSMN_ERROR_INVAL;
+          }
+          parser->pos++;
+        }
+        parser->pos--;
+        break;
+      /* Unexpected symbol */
+      default:
+        parser->pos = start;
+        return JSMN_ERROR_INVAL;
+      }
+    }
+  }
+  parser->pos = start;
+  return JSMN_ERROR_PART;
+}
+
+/**
+ * Parse JSON string and fill tokens.
+ */
+JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len,
+                        jsmntok_t *tokens, const unsigned int num_tokens) {
+  int r;
+  int i;
+  jsmntok_t *token;
+  int count = parser->toknext;
+
+  for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+    char c;
+    jsmntype_t type;
+
+    c = js[parser->pos];
+    switch (c) {
+    case '{':
+    case '[':
+      count++;
+      if (tokens == NULL) {
+        break;
+      }
+      token = jsmn_alloc_token(parser, tokens, num_tokens);
+      if (token == NULL) {
+        return JSMN_ERROR_NOMEM;
+      }
+      if (parser->toksuper != -1) {
+        jsmntok_t *t = &tokens[parser->toksuper];
+#ifdef JSMN_STRICT
+        /* In strict mode an object or array can't become a key */
+        if (t->type == JSMN_OBJECT) {
+          return JSMN_ERROR_INVAL;
+        }
+#endif
+        t->size++;
+#ifdef JSMN_PARENT_LINKS
+        token->parent = parser->toksuper;
+#endif
+      }
+      token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
+      token->start = parser->pos;
+      parser->toksuper = parser->toknext - 1;
+      break;
+    case '}':
+    case ']':
+      if (tokens == NULL) {
+        break;
+      }
+      type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
+#ifdef JSMN_PARENT_LINKS
+      if (parser->toknext < 1) {
+        return JSMN_ERROR_INVAL;
+      }
+      token = &tokens[parser->toknext - 1];
+      for (;;) {
+        if (token->start != -1 && token->end == -1) {
+          if (token->type != type) {
+            return JSMN_ERROR_INVAL;
+          }
+          token->end = parser->pos + 1;
+          parser->toksuper = token->parent;
+          break;
+        }
+        if (token->parent == -1) {
+          if (token->type != type || parser->toksuper == -1) {
+            return JSMN_ERROR_INVAL;
+          }
+          break;
+        }
+        token = &tokens[token->parent];
+      }
+#else
+      for (i = parser->toknext - 1; i >= 0; i--) {
+        token = &tokens[i];
+        if (token->start != -1 && token->end == -1) {
+          if (token->type != type) {
+            return JSMN_ERROR_INVAL;
+          }
+          parser->toksuper = -1;
+          token->end = parser->pos + 1;
+          break;
+        }
+      }
+      /* Error if unmatched closing bracket */
+      if (i == -1) {
+        return JSMN_ERROR_INVAL;
+      }
+      for (; i >= 0; i--) {
+        token = &tokens[i];
+        if (token->start != -1 && token->end == -1) {
+          parser->toksuper = i;
+          break;
+        }
+      }
+#endif
+      break;
+    case '\"':
+      r = jsmn_parse_string(parser, js, len, tokens, num_tokens);
+      if (r < 0) {
+        return r;
+      }
+      count++;
+      if (parser->toksuper != -1 && tokens != NULL) {
+        tokens[parser->toksuper].size++;
+      }
+      break;
+    case '\t':
+    case '\r':
+    case '\n':
+    case ' ':
+      break;
+    case ':':
+      parser->toksuper = parser->toknext - 1;
+      break;
+    case ',':
+      if (tokens != NULL && parser->toksuper != -1 &&
+          tokens[parser->toksuper].type != JSMN_ARRAY &&
+          tokens[parser->toksuper].type != JSMN_OBJECT) {
+#ifdef JSMN_PARENT_LINKS
+        parser->toksuper = tokens[parser->toksuper].parent;
+#else
+        for (i = parser->toknext - 1; i >= 0; i--) {
+          if (tokens[i].type == JSMN_ARRAY || tokens[i].type == JSMN_OBJECT) {
+            if (tokens[i].start != -1 && tokens[i].end == -1) {
+              parser->toksuper = i;
+              break;
+            }
+          }
+        }
+#endif
+      }
+      break;
+#ifdef JSMN_STRICT
+    /* In strict mode primitives are: numbers and booleans */
+    case '-':
+    case '0':
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+    case 't':
+    case 'f':
+    case 'n':
+      /* And they must not be keys of the object */
+      if (tokens != NULL && parser->toksuper != -1) {
+        const jsmntok_t *t = &tokens[parser->toksuper];
+        if (t->type == JSMN_OBJECT ||
+            (t->type == JSMN_STRING && t->size != 0)) {
+          return JSMN_ERROR_INVAL;
+        }
+      }
+#else
+    /* In non-strict mode every unquoted value is a primitive */
+    default:
+#endif
+      r = jsmn_parse_primitive(parser, js, len, tokens, num_tokens);
+      if (r < 0) {
+        return r;
+      }
+      count++;
+      if (parser->toksuper != -1 && tokens != NULL) {
+        tokens[parser->toksuper].size++;
+      }
+      break;
+
+#ifdef JSMN_STRICT
+    /* Unexpected char in strict mode */
+    default:
+      return JSMN_ERROR_INVAL;
+#endif
+    }
+  }
+
+  if (tokens != NULL) {
+    for (i = parser->toknext - 1; i >= 0; i--) {
+      /* Unmatched opened object or array */
+      if (tokens[i].start != -1 && tokens[i].end == -1) {
+        return JSMN_ERROR_PART;
+      }
+    }
+  }
+
+  return count;
+}
+
+/**
+ * Creates a new parser based over a given buffer with an array of tokens
+ * available.
+ */
+JSMN_API void jsmn_init(jsmn_parser *parser) {
+  parser->pos = 0;
+  parser->toknext = 0;
+  parser->toksuper = -1;
+}
+
+#endif /* JSMN_HEADER */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* JSMN_H */
diff --git a/grub-core/lib/json/json.c b/grub-core/lib/json/json.c
new file mode 100644
index 000000000..2bddd8c46
--- /dev/null
+++ b/grub-core/lib/json/json.c
@@ -0,0 +1,23 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2019  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+
+#include "jsmn.h"
+
+GRUB_MOD_LICENSE ("GPLv3");
-- 
2.24.0




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