Import existing code to mqhttp

1 files changed, 263 insertions, 0 deletions

diff --git a/uhttp.c b/uhttp.c
new file mode 100644
index 0000000..9e6ec6f
--- /dev/null
+++ b/uhttp.c
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2021 Mikhail Burakov. This file is part of MQhTTp.
+ *
+ * MQhTTp 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.
+ *
+ * MQhTTp 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 MQhTTp.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "uhttp.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct Uhttp {
+  struct {
+    char* data;
+    size_t alloc;
+    size_t size;
+  } buffer;
+  struct {
+    const char* method;
+    const char* target;
+    const char* body;
+    size_t body_size;
+  } public;
+  struct {
+    _Bool (*state)(struct Uhttp*, char*);
+    const char* field_name;
+    const char* field_value;
+    char* maybe_ows;
+    _Bool maybe_eol;
+  } parser;
+};
+
+static _Bool StrEq(const char* a, const char* b) {
+  for (; *a && *b; a++, b++) {
+    if (tolower(*a) != tolower(*b)) return 0;
+  }
+  return *a == *b;
+}
+
+static _Bool UhttpOnMethod(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnTarget(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnVersion(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnFieldName(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnFieldValue(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnBody(struct Uhttp* uhttp, char* glyph);
+static _Bool UhttpOnStopped(struct Uhttp* uhttp, char* glyph);
+
+static _Bool UhttpOnMethod(struct Uhttp* uhttp, char* glyph) {
+  switch (*glyph) {
+    case ' ':
+      if (!uhttp->public.method) return 0;
+      uhttp->parser.state = UhttpOnTarget;
+      *glyph = 0;
+      return 1;
+    default:
+      if (!isgraph(*glyph)) return 0;
+      if (!uhttp->public.method) uhttp->public.method = glyph;
+      return 1;
+  }
+}
+
+static _Bool UhttpOnTarget(struct Uhttp* uhttp, char* glyph) {
+  switch (*glyph) {
+    case ' ':
+      if (!uhttp->public.target) return 0;
+      uhttp->parser.state = UhttpOnVersion;
+      *glyph = 0;
+      return 1;
+    default:
+      if (!isgraph(*glyph)) return 0;
+      if (!uhttp->public.target) uhttp->public.target = glyph;
+      return 1;
+  }
+}
+
+static _Bool UhttpOnVersion(struct Uhttp* uhttp, char* glyph) {
+  switch (*glyph) {
+    case '\r':
+      if (uhttp->parser.maybe_eol) return 0;
+      uhttp->parser.maybe_eol = 1;
+      return 1;
+    case '\n':
+      if (!uhttp->parser.maybe_eol) return 0;
+      uhttp->parser.state = UhttpOnFieldName;
+      uhttp->parser.maybe_eol = 0;
+      return 1;
+    default:
+      if (uhttp->parser.maybe_eol) return 0;
+      if (!isprint(*glyph)) return 0;
+      return 1;
+  }
+}
+
+static _Bool UhttpOnFieldName(struct Uhttp* uhttp, char* glyph) {
+  switch (*glyph) {
+    case '\r':
+      if (uhttp->parser.maybe_eol) return 0;
+      uhttp->parser.maybe_eol = 1;
+      return 1;
+    case '\n':
+      if (!uhttp->parser.maybe_eol) return 0;
+      uhttp->parser.state =
+          uhttp->public.body_size ? UhttpOnBody : UhttpOnStopped;
+      return 1;
+    case ' ':
+      return 0;
+    case ':':
+      if (uhttp->parser.maybe_eol) return 0;
+      if (!uhttp->parser.field_name) return 0;
+      uhttp->parser.state = UhttpOnFieldValue;
+      uhttp->parser.field_value = NULL;
+      *glyph = 0;
+      return 1;
+    default:
+      if (uhttp->parser.maybe_eol) return 0;
+      if (!isgraph(*glyph)) return 0;
+      if (!uhttp->parser.field_name) uhttp->parser.field_name = glyph;
+      return 1;
+  }
+}
+
+static _Bool UhttpOnFieldValue(struct Uhttp* uhttp, char* glyph) {
+  switch (*glyph) {
+    case '\r':
+      if (uhttp->parser.maybe_eol) return 0;
+      uhttp->parser.maybe_ows = glyph;
+      uhttp->parser.maybe_eol = 1;
+      return 1;
+    case '\n':
+      if (!uhttp->parser.maybe_eol) return 0;
+      if (!uhttp->parser.field_value) return 0;
+      *uhttp->parser.maybe_ows = 0;
+      if (!uhttp->public.body_size &&
+          StrEq(uhttp->parser.field_name, "Content-Length"))
+        uhttp->public.body_size = (size_t)atoi(uhttp->parser.field_value);
+      uhttp->parser.state = UhttpOnFieldName;
+      uhttp->parser.field_name = NULL;
+      uhttp->parser.maybe_eol = 0;
+      return 1;
+    case '\t':
+    case ' ':
+      if (uhttp->parser.maybe_eol) return 0;
+      if (!uhttp->parser.field_value) return 1;
+      if (!uhttp->parser.maybe_ows) uhttp->parser.maybe_ows = glyph;
+      return 1;
+    default:
+      if (uhttp->parser.maybe_eol) return 0;
+      if (!isgraph(*glyph)) return 0;
+      if (!uhttp->parser.field_value) uhttp->parser.field_value = glyph;
+      uhttp->parser.maybe_ows = NULL;
+      return 1;
+  }
+}
+
+static _Bool UhttpOnBody(struct Uhttp* uhttp, char* glyph) {
+  if (!uhttp->public.body) uhttp->public.body = glyph;
+  ssize_t body_size = glyph - uhttp->public.body + 1;
+  if ((size_t)body_size == uhttp->public.body_size)
+    uhttp->parser.state = UhttpOnStopped;
+  return 1;
+}
+
+static _Bool UhttpOnStopped(struct Uhttp* uhttp, char* glyph) {
+  (void)uhttp;
+  (void)glyph;
+  return 0;
+}
+
+static void UhttpRelocateBuffer(struct Uhttp* uhttp, char* data) {
+  if (uhttp->public.method)
+    uhttp->public.method = data + (uhttp->public.method - uhttp->buffer.data);
+  if (uhttp->public.target)
+    uhttp->public.target = data + (uhttp->public.target - uhttp->buffer.data);
+  if (uhttp->public.body)
+    uhttp->public.body = data + (uhttp->public.body - uhttp->buffer.data);
+  if (uhttp->parser.field_name) {
+    uhttp->parser.field_name =
+        data + (uhttp->parser.field_name - uhttp->buffer.data);
+  }
+  if (uhttp->parser.field_value) {
+    uhttp->parser.field_value =
+        data + (uhttp->parser.field_value - uhttp->buffer.data);
+  }
+  if (uhttp->parser.maybe_ows) {
+    uhttp->parser.maybe_ows =
+        data + (uhttp->parser.maybe_ows - uhttp->buffer.data);
+  }
+  uhttp->buffer.data = data;
+}
+
+struct Uhttp* UhttpCreate() {
+  struct Uhttp* result = calloc(1, sizeof(struct Uhttp));
+  UhttpReset(result);
+  return result;
+}
+
+void UhttpDestroy(struct Uhttp* uhttp) {
+  free(uhttp->buffer.data);
+  free(uhttp);
+}
+
+void UhttpReset(struct Uhttp* uhttp) {
+  const struct Uhttp reset = {.buffer.data = uhttp->buffer.data,
+                              .buffer.alloc = uhttp->buffer.alloc,
+                              .parser.state = UhttpOnMethod};
+  *uhttp = reset;
+}
+
+void* UhttpAllocate(struct Uhttp* uhttp, size_t size) {
+  size_t alloc = uhttp->buffer.size + size;
+  if (alloc > uhttp->buffer.alloc) {
+    char* data = realloc(uhttp->buffer.data, alloc);
+    if (!data) return NULL;
+    if (data != uhttp->buffer.data) UhttpRelocateBuffer(uhttp, data);
+    uhttp->buffer.alloc = alloc;
+  }
+  return uhttp->buffer.data + uhttp->buffer.size;
+}
+
+enum UhttpResult UhttpConsume(struct Uhttp* uhttp, size_t size) {
+  if (uhttp->buffer.size + size > uhttp->buffer.alloc)
+    return kUhttpResultTerminate;
+  size_t end = uhttp->buffer.size + size;
+  for (; uhttp->buffer.size < end; uhttp->buffer.size++) {
+    if (!uhttp->parser.state(uhttp, &uhttp->buffer.data[uhttp->buffer.size])) {
+      uhttp->parser.state = UhttpOnStopped;
+      return kUhttpResultFailure;
+    }
+    if (uhttp->parser.state == UhttpOnStopped) {
+      return kUhttpResultFinished;
+    }
+  }
+  return kUhttpResultWantMore;
+}
+
+const char* UhttpGetMethod(const struct Uhttp* uhttp) {
+  return uhttp->public.method;
+}
+
+const char* UhttpGetTarget(const struct Uhttp* uhttp) {
+  return uhttp->public.target;
+}
+
+const char* UhttpGetBody(const struct Uhttp* uhttp) {
+  return uhttp->public.body;
+}
+
+size_t UhttpGetBodySize(const struct Uhttp* uhttp) {
+  return uhttp->public.body_size;
+}