add cl-parser.c

1 files changed, 150 insertions, 0 deletions

diff --git a/cl-parser.c b/cl-parser.c
new file mode 100644
index 0000000..83863c5
--- /dev/null
+++ b/cl-parser.c
@@ -0,0 +1,150 @@
+#include "internal.h"
+
+//
+// content length functions
+//
+
+static const fhp_cl_parser_t FHP_DEFAULT_CL_PARSER = {
+  .state = FHP_CL_STATE_INIT,
+  .val = 0,
+  .err = FHP_OK,
+};
+
+fhp_err_t
+fhp_cl_parser_init(fhp_cl_parser_t * const p) {
+  // init parser
+  *p = FHP_DEFAULT_CL_PARSER;
+
+  // return succes
+  return FHP_OK;
+}
+
+static fhp_err_t
+fhp_cl_parser_push_byte(
+  fhp_cl_parser_t * const p,
+  uint8_t byte
+) {
+retry:
+  switch (p->state) {
+  case FHP_CL_STATE_INIT:
+    switch (byte) {
+    CASE_OWS_CHARS
+      // ignore
+      break;
+    CASE_DIGIT_CHARS
+      // set state
+      p->state = FHP_CL_STATE_DATA;
+      goto retry;
+
+      break;
+    default:
+      // invalid character before content-length
+      return FHP_ERR_INVALID_CHAR_BEFORE_CL;
+    }
+
+    break;
+  case FHP_CL_STATE_DATA:
+    switch (byte) {
+    CASE_OWS_CHARS
+      // set state
+      p->state = FHP_CL_STATE_TRAILING_SPACES;
+      goto retry;
+
+      break;
+    CASE_DIGIT_CHARS
+      {
+        // cache old value
+        uint64_t old_val = p->val;
+
+        // update value
+        p->val = p->val * 10 + (byte - '0');
+
+        // check for overflow
+        if (p->val < old_val)
+          return FHP_ERR_CL_OVERFLOW;
+      }
+
+      break;
+    default:
+      // invalid character in content-length
+      return FHP_ERR_INVALID_CHAR_IN_CL;
+    }
+
+    break;
+  case FHP_CL_STATE_TRAILING_SPACES:
+    switch (byte) {
+    CASE_OWS_CHARS
+      // ignore trailing spaces
+
+      break;
+    default:
+      // invalid character after content-length
+      return FHP_ERR_INVALID_CHAR_AFTER_CL;
+    }
+
+    break;
+  case FHP_CL_STATE_ERROR:
+    // return last error
+    return p->err;
+
+    break;
+  case FHP_CL_STATE_DONE:
+    // shouldn't be reached
+    return FHP_ERR_CL_PARSER_DONE;
+
+    break;
+  default:
+    // never reached
+    return FHP_ERR_BAD_CL_STATE;
+  }
+
+  // return succes
+  return FHP_OK;
+}
+
+fhp_err_t
+fhp_cl_parser_push(
+  fhp_cl_parser_t *p,
+  uint8_t * const buf,
+  size_t len
+) {
+  for (size_t i = 0; i < len; i++) {
+    // push byte
+    fhp_err_t err = fhp_cl_parser_push_byte(p, buf[i]);
+
+    // check error
+    if (err != FHP_OK) {
+      // cache error
+      p->err = err;
+
+      // set state
+      p->state = FHP_CL_STATE_ERROR;
+
+      // return error
+      return err;
+    }
+  }
+
+  // return succes
+  return FHP_OK;
+}
+
+fhp_err_t
+fhp_cl_parser_done(
+  fhp_cl_parser_t * const p,
+  uint64_t * const ret_val
+) {
+  // check for error
+  if (p->err != FHP_OK)
+    return p->err;
+
+  // set state
+  p->state = FHP_TE_STATE_DONE;
+
+  // save number of tes
+  if (ret_val)
+    *ret_val = p->val;
+
+  // return success
+  return FHP_OK;
+}