Merge github.com:grpc/grpc into newlines

6 files changed, 1047 insertions, 0 deletions

diff --git a/src/core/lib/slice/percent_encoding.c b/src/core/lib/slice/percent_encoding.c
new file mode 100644
index 0000000000..b9e35f1c71
--- /dev/null
+++ b/src/core/lib/slice/percent_encoding.c
@@ -0,0 +1,180 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/slice/percent_encoding.h"
+
+#include <grpc/support/log.h>
+
+const uint8_t grpc_url_percent_encoding_unreserved_bytes[256 / 8] = {
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0xfe, 0xff, 0xff,
+    0x87, 0xfe, 0xff, 0xff, 0x47, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+const uint8_t grpc_compatible_percent_encoding_unreserved_bytes[256 / 8] = {
+    0x00, 0x00, 0x00, 0x00, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+static bool is_unreserved_character(uint8_t c,
+                                    const uint8_t *unreserved_bytes) {
+  return ((unreserved_bytes[c / 8] >> (c % 8)) & 1) != 0;
+}
+
+grpc_slice grpc_percent_encode_slice(grpc_slice slice,
+                                     const uint8_t *unreserved_bytes) {
+  static const uint8_t hex[] = "0123456789ABCDEF";
+
+  // first pass: count the number of bytes needed to output this string
+  size_t output_length = 0;
+  const uint8_t *slice_start = GRPC_SLICE_START_PTR(slice);
+  const uint8_t *slice_end = GRPC_SLICE_END_PTR(slice);
+  const uint8_t *p;
+  bool any_reserved_bytes = false;
+  for (p = slice_start; p < slice_end; p++) {
+    bool unres = is_unreserved_character(*p, unreserved_bytes);
+    output_length += unres ? 1 : 3;
+    any_reserved_bytes |= !unres;
+  }
+  // no unreserved bytes: return the string unmodified
+  if (!any_reserved_bytes) {
+    return grpc_slice_ref(slice);
+  }
+  // second pass: actually encode
+  grpc_slice out = grpc_slice_malloc(output_length);
+  uint8_t *q = GRPC_SLICE_START_PTR(out);
+  for (p = slice_start; p < slice_end; p++) {
+    if (is_unreserved_character(*p, unreserved_bytes)) {
+      *q++ = *p;
+    } else {
+      *q++ = '%';
+      *q++ = hex[*p >> 4];
+      *q++ = hex[*p & 15];
+    }
+  }
+  GPR_ASSERT(q == GRPC_SLICE_END_PTR(out));
+  return out;
+}
+
+static bool valid_hex(const uint8_t *p, const uint8_t *end) {
+  if (p >= end) return false;
+  return (*p >= '0' && *p <= '9') || (*p >= 'a' && *p <= 'f') ||
+         (*p >= 'A' && *p <= 'F');
+}
+
+static uint8_t dehex(uint8_t c) {
+  if (c >= '0' && c <= '9') return (uint8_t)(c - '0');
+  if (c >= 'A' && c <= 'F') return (uint8_t)(c - 'A' + 10);
+  if (c >= 'a' && c <= 'f') return (uint8_t)(c - 'a' + 10);
+  GPR_UNREACHABLE_CODE(return 255);
+}
+
+bool grpc_strict_percent_decode_slice(grpc_slice slice_in,
+                                      const uint8_t *unreserved_bytes,
+                                      grpc_slice *slice_out) {
+  const uint8_t *p = GRPC_SLICE_START_PTR(slice_in);
+  const uint8_t *in_end = GRPC_SLICE_END_PTR(slice_in);
+  size_t out_length = 0;
+  bool any_percent_encoded_stuff = false;
+  while (p != in_end) {
+    if (*p == '%') {
+      if (!valid_hex(++p, in_end)) return false;
+      if (!valid_hex(++p, in_end)) return false;
+      p++;
+      out_length++;
+      any_percent_encoded_stuff = true;
+    } else if (is_unreserved_character(*p, unreserved_bytes)) {
+      p++;
+      out_length++;
+    } else {
+      return false;
+    }
+  }
+  if (!any_percent_encoded_stuff) {
+    *slice_out = grpc_slice_ref(slice_in);
+    return true;
+  }
+  p = GRPC_SLICE_START_PTR(slice_in);
+  *slice_out = grpc_slice_malloc(out_length);
+  uint8_t *q = GRPC_SLICE_START_PTR(*slice_out);
+  while (p != in_end) {
+    if (*p == '%') {
+      *q++ = (uint8_t)(dehex(p[1]) << 4) | (dehex(p[2]));
+      p += 3;
+    } else {
+      *q++ = *p++;
+    }
+  }
+  GPR_ASSERT(q == GRPC_SLICE_END_PTR(*slice_out));
+  return true;
+}
+
+grpc_slice grpc_permissive_percent_decode_slice(grpc_slice slice_in) {
+  const uint8_t *p = GRPC_SLICE_START_PTR(slice_in);
+  const uint8_t *in_end = GRPC_SLICE_END_PTR(slice_in);
+  size_t out_length = 0;
+  bool any_percent_encoded_stuff = false;
+  while (p != in_end) {
+    if (*p == '%') {
+      if (!valid_hex(p + 1, in_end) || !valid_hex(p + 2, in_end)) {
+        p++;
+        out_length++;
+      } else {
+        p += 3;
+        out_length++;
+        any_percent_encoded_stuff = true;
+      }
+    } else {
+      p++;
+      out_length++;
+    }
+  }
+  if (!any_percent_encoded_stuff) {
+    return grpc_slice_ref(slice_in);
+  }
+  p = GRPC_SLICE_START_PTR(slice_in);
+  grpc_slice out = grpc_slice_malloc(out_length);
+  uint8_t *q = GRPC_SLICE_START_PTR(out);
+  while (p != in_end) {
+    if (*p == '%') {
+      if (!valid_hex(p + 1, in_end) || !valid_hex(p + 2, in_end)) {
+        *q++ = *p++;
+      } else {
+        *q++ = (uint8_t)(dehex(p[1]) << 4) | (dehex(p[2]));
+        p += 3;
+      }
+    } else {
+      *q++ = *p++;
+    }
+  }
+  GPR_ASSERT(q == GRPC_SLICE_END_PTR(out));
+  return out;
+}
diff --git a/src/core/lib/slice/percent_encoding.h b/src/core/lib/slice/percent_encoding.h
new file mode 100644
index 0000000000..189bdbe312
--- /dev/null
+++ b/src/core/lib/slice/percent_encoding.h
@@ -0,0 +1,78 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H
+#define GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H
+
+/* Percent encoding and decoding of slices.
+   Transforms arbitrary strings into safe-for-transmission strings by using
+   variants of percent encoding (RFC 3986).
+   Two major variants are supplied: one that strictly matches URL encoding,
+     and another which applies percent encoding only to non-http2 header
+     bytes (the 'compatible' variant) */
+
+#include <stdbool.h>
+
+#include <grpc/slice.h>
+
+/* URL percent encoding spec bitfield (usabel as 'unreserved_bytes' in
+   grpc_percent_encode_slice, grpc_strict_percent_decode_slice).
+   Flags [A-Za-z0-9-_.~] as unreserved bytes for the percent encoding routines
+   */
+extern const uint8_t grpc_url_percent_encoding_unreserved_bytes[256 / 8];
+/* URL percent encoding spec bitfield (usabel as 'unreserved_bytes' in
+   grpc_percent_encode_slice, grpc_strict_percent_decode_slice).
+   Flags ascii7 non-control characters excluding '%' as unreserved bytes for the
+   percent encoding routines */
+extern const uint8_t grpc_compatible_percent_encoding_unreserved_bytes[256 / 8];
+
+/* Percent-encode a slice, returning the new slice (this cannot fail):
+   unreserved_bytes is a bitfield indicating which bytes are considered
+   unreserved and thus do not need percent encoding */
+grpc_slice grpc_percent_encode_slice(grpc_slice slice,
+                                     const uint8_t *unreserved_bytes);
+/* Percent-decode a slice, strictly.
+   If the input is legal (contains no unreserved bytes, and legal % encodings),
+   returns true and sets *slice_out to the decoded slice.
+   If the input is not legal, returns false and leaves *slice_out untouched.
+   unreserved_bytes is a bitfield indicating which bytes are considered
+   unreserved and thus do not need percent encoding */
+bool grpc_strict_percent_decode_slice(grpc_slice slice_in,
+                                      const uint8_t *unreserved_bytes,
+                                      grpc_slice *slice_out);
+/* Percent-decode a slice, permissively.
+   If a % triplet can not be decoded, pass it through verbatim.
+   This cannot fail. */
+grpc_slice grpc_permissive_percent_decode_slice(grpc_slice slice_in);
+
+#endif /* GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H */
diff --git a/src/core/lib/slice/slice.c b/src/core/lib/slice/slice.c
new file mode 100644
index 0000000000..52977e6d9a
--- /dev/null
+++ b/src/core/lib/slice/slice.c
@@ -0,0 +1,358 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/slice.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include <string.h>
+
+grpc_slice gpr_empty_slice(void) {
+  grpc_slice out;
+  out.refcount = 0;
+  out.data.inlined.length = 0;
+  return out;
+}
+
+grpc_slice grpc_slice_ref(grpc_slice slice) {
+  if (slice.refcount) {
+    slice.refcount->ref(slice.refcount);
+  }
+  return slice;
+}
+
+void grpc_slice_unref(grpc_slice slice) {
+  if (slice.refcount) {
+    slice.refcount->unref(slice.refcount);
+  }
+}
+
+/* grpc_slice_from_static_string support structure - a refcount that does
+   nothing */
+static void noop_ref_or_unref(void *unused) {}
+
+static grpc_slice_refcount noop_refcount = {noop_ref_or_unref,
+                                            noop_ref_or_unref};
+
+grpc_slice grpc_slice_from_static_string(const char *s) {
+  grpc_slice slice;
+  slice.refcount = &noop_refcount;
+  slice.data.refcounted.bytes = (uint8_t *)s;
+  slice.data.refcounted.length = strlen(s);
+  return slice;
+}
+
+/* grpc_slice_new support structures - we create a refcount object extended
+   with the user provided data pointer & destroy function */
+typedef struct new_slice_refcount {
+  grpc_slice_refcount rc;
+  gpr_refcount refs;
+  void (*user_destroy)(void *);
+  void *user_data;
+} new_slice_refcount;
+
+static void new_slice_ref(void *p) {
+  new_slice_refcount *r = p;
+  gpr_ref(&r->refs);
+}
+
+static void new_slice_unref(void *p) {
+  new_slice_refcount *r = p;
+  if (gpr_unref(&r->refs)) {
+    r->user_destroy(r->user_data);
+    gpr_free(r);
+  }
+}
+
+grpc_slice grpc_slice_new_with_user_data(void *p, size_t len,
+                                         void (*destroy)(void *),
+                                         void *user_data) {
+  grpc_slice slice;
+  new_slice_refcount *rc = gpr_malloc(sizeof(new_slice_refcount));
+  gpr_ref_init(&rc->refs, 1);
+  rc->rc.ref = new_slice_ref;
+  rc->rc.unref = new_slice_unref;
+  rc->user_destroy = destroy;
+  rc->user_data = user_data;
+
+  slice.refcount = &rc->rc;
+  slice.data.refcounted.bytes = p;
+  slice.data.refcounted.length = len;
+  return slice;
+}
+
+grpc_slice grpc_slice_new(void *p, size_t len, void (*destroy)(void *)) {
+  /* Pass "p" to *destroy when the slice is no longer needed. */
+  return grpc_slice_new_with_user_data(p, len, destroy, p);
+}
+
+/* grpc_slice_new_with_len support structures - we create a refcount object
+   extended with the user provided data pointer & destroy function */
+typedef struct new_with_len_slice_refcount {
+  grpc_slice_refcount rc;
+  gpr_refcount refs;
+  void *user_data;
+  size_t user_length;
+  void (*user_destroy)(void *, size_t);
+} new_with_len_slice_refcount;
+
+static void new_with_len_ref(void *p) {
+  new_with_len_slice_refcount *r = p;
+  gpr_ref(&r->refs);
+}
+
+static void new_with_len_unref(void *p) {
+  new_with_len_slice_refcount *r = p;
+  if (gpr_unref(&r->refs)) {
+    r->user_destroy(r->user_data, r->user_length);
+    gpr_free(r);
+  }
+}
+
+grpc_slice grpc_slice_new_with_len(void *p, size_t len,
+                                   void (*destroy)(void *, size_t)) {
+  grpc_slice slice;
+  new_with_len_slice_refcount *rc =
+      gpr_malloc(sizeof(new_with_len_slice_refcount));
+  gpr_ref_init(&rc->refs, 1);
+  rc->rc.ref = new_with_len_ref;
+  rc->rc.unref = new_with_len_unref;
+  rc->user_destroy = destroy;
+  rc->user_data = p;
+  rc->user_length = len;
+
+  slice.refcount = &rc->rc;
+  slice.data.refcounted.bytes = p;
+  slice.data.refcounted.length = len;
+  return slice;
+}
+
+grpc_slice grpc_slice_from_copied_buffer(const char *source, size_t length) {
+  grpc_slice slice = grpc_slice_malloc(length);
+  memcpy(GRPC_SLICE_START_PTR(slice), source, length);
+  return slice;
+}
+
+grpc_slice grpc_slice_from_copied_string(const char *source) {
+  return grpc_slice_from_copied_buffer(source, strlen(source));
+}
+
+typedef struct {
+  grpc_slice_refcount base;
+  gpr_refcount refs;
+} malloc_refcount;
+
+static void malloc_ref(void *p) {
+  malloc_refcount *r = p;
+  gpr_ref(&r->refs);
+}
+
+static void malloc_unref(void *p) {
+  malloc_refcount *r = p;
+  if (gpr_unref(&r->refs)) {
+    gpr_free(r);
+  }
+}
+
+grpc_slice grpc_slice_malloc(size_t length) {
+  grpc_slice slice;
+
+  if (length > sizeof(slice.data.inlined.bytes)) {
+    /* Memory layout used by the slice created here:
+
+       +-----------+----------------------------------------------------------+
+       | refcount  | bytes                                                    |
+       +-----------+----------------------------------------------------------+
+
+       refcount is a malloc_refcount
+       bytes is an array of bytes of the requested length
+       Both parts are placed in the same allocation returned from gpr_malloc */
+    malloc_refcount *rc = gpr_malloc(sizeof(malloc_refcount) + length);
+
+    /* Initial refcount on rc is 1 - and it's up to the caller to release
+       this reference. */
+    gpr_ref_init(&rc->refs, 1);
+
+    rc->base.ref = malloc_ref;
+    rc->base.unref = malloc_unref;
+
+    /* Build up the slice to be returned. */
+    /* The slices refcount points back to the allocated block. */
+    slice.refcount = &rc->base;
+    /* The data bytes are placed immediately after the refcount struct */
+    slice.data.refcounted.bytes = (uint8_t *)(rc + 1);
+    /* And the length of the block is set to the requested length */
+    slice.data.refcounted.length = length;
+  } else {
+    /* small slice: just inline the data */
+    slice.refcount = NULL;
+    slice.data.inlined.length = (uint8_t)length;
+  }
+  return slice;
+}
+
+grpc_slice grpc_slice_sub_no_ref(grpc_slice source, size_t begin, size_t end) {
+  grpc_slice subset;
+
+  GPR_ASSERT(end >= begin);
+
+  if (source.refcount) {
+    /* Enforce preconditions */
+    GPR_ASSERT(source.data.refcounted.length >= end);
+
+    /* Build the result */
+    subset.refcount = source.refcount;
+    /* Point into the source array */
+    subset.data.refcounted.bytes = source.data.refcounted.bytes + begin;
+    subset.data.refcounted.length = end - begin;
+  } else {
+    /* Enforce preconditions */
+    GPR_ASSERT(source.data.inlined.length >= end);
+    subset.refcount = NULL;
+    subset.data.inlined.length = (uint8_t)(end - begin);
+    memcpy(subset.data.inlined.bytes, source.data.inlined.bytes + begin,
+           end - begin);
+  }
+  return subset;
+}
+
+grpc_slice grpc_slice_sub(grpc_slice source, size_t begin, size_t end) {
+  grpc_slice subset;
+
+  if (end - begin <= sizeof(subset.data.inlined.bytes)) {
+    subset.refcount = NULL;
+    subset.data.inlined.length = (uint8_t)(end - begin);
+    memcpy(subset.data.inlined.bytes, GRPC_SLICE_START_PTR(source) + begin,
+           end - begin);
+  } else {
+    subset = grpc_slice_sub_no_ref(source, begin, end);
+    /* Bump the refcount */
+    subset.refcount->ref(subset.refcount);
+  }
+  return subset;
+}
+
+grpc_slice grpc_slice_split_tail(grpc_slice *source, size_t split) {
+  grpc_slice tail;
+
+  if (source->refcount == NULL) {
+    /* inlined data, copy it out */
+    GPR_ASSERT(source->data.inlined.length >= split);
+    tail.refcount = NULL;
+    tail.data.inlined.length = (uint8_t)(source->data.inlined.length - split);
+    memcpy(tail.data.inlined.bytes, source->data.inlined.bytes + split,
+           tail.data.inlined.length);
+    source->data.inlined.length = (uint8_t)split;
+  } else {
+    size_t tail_length = source->data.refcounted.length - split;
+    GPR_ASSERT(source->data.refcounted.length >= split);
+    if (tail_length < sizeof(tail.data.inlined.bytes)) {
+      /* Copy out the bytes - it'll be cheaper than refcounting */
+      tail.refcount = NULL;
+      tail.data.inlined.length = (uint8_t)tail_length;
+      memcpy(tail.data.inlined.bytes, source->data.refcounted.bytes + split,
+             tail_length);
+    } else {
+      /* Build the result */
+      tail.refcount = source->refcount;
+      /* Bump the refcount */
+      tail.refcount->ref(tail.refcount);
+      /* Point into the source array */
+      tail.data.refcounted.bytes = source->data.refcounted.bytes + split;
+      tail.data.refcounted.length = tail_length;
+    }
+    source->data.refcounted.length = split;
+  }
+
+  return tail;
+}
+
+grpc_slice grpc_slice_split_head(grpc_slice *source, size_t split) {
+  grpc_slice head;
+
+  if (source->refcount == NULL) {
+    GPR_ASSERT(source->data.inlined.length >= split);
+
+    head.refcount = NULL;
+    head.data.inlined.length = (uint8_t)split;
+    memcpy(head.data.inlined.bytes, source->data.inlined.bytes, split);
+    source->data.inlined.length =
+        (uint8_t)(source->data.inlined.length - split);
+    memmove(source->data.inlined.bytes, source->data.inlined.bytes + split,
+            source->data.inlined.length);
+  } else if (split < sizeof(head.data.inlined.bytes)) {
+    GPR_ASSERT(source->data.refcounted.length >= split);
+
+    head.refcount = NULL;
+    head.data.inlined.length = (uint8_t)split;
+    memcpy(head.data.inlined.bytes, source->data.refcounted.bytes, split);
+    source->data.refcounted.bytes += split;
+    source->data.refcounted.length -= split;
+  } else {
+    GPR_ASSERT(source->data.refcounted.length >= split);
+
+    /* Build the result */
+    head.refcount = source->refcount;
+    /* Bump the refcount */
+    head.refcount->ref(head.refcount);
+    /* Point into the source array */
+    head.data.refcounted.bytes = source->data.refcounted.bytes;
+    head.data.refcounted.length = split;
+    source->data.refcounted.bytes += split;
+    source->data.refcounted.length -= split;
+  }
+
+  return head;
+}
+
+int grpc_slice_cmp(grpc_slice a, grpc_slice b) {
+  int d = (int)(GRPC_SLICE_LENGTH(a) - GRPC_SLICE_LENGTH(b));
+  if (d != 0) return d;
+  return memcmp(GRPC_SLICE_START_PTR(a), GRPC_SLICE_START_PTR(b),
+                GRPC_SLICE_LENGTH(a));
+}
+
+int grpc_slice_str_cmp(grpc_slice a, const char *b) {
+  size_t b_length = strlen(b);
+  int d = (int)(GRPC_SLICE_LENGTH(a) - b_length);
+  if (d != 0) return d;
+  return memcmp(GRPC_SLICE_START_PTR(a), b, b_length);
+}
+
+int grpc_slice_is_equivalent(grpc_slice a, grpc_slice b) {
+  if (a.refcount == NULL || b.refcount == NULL) {
+    return grpc_slice_cmp(a, b) == 0;
+  }
+  return a.data.refcounted.length == b.data.refcounted.length &&
+         a.data.refcounted.bytes == b.data.refcounted.bytes;
+}
diff --git a/src/core/lib/slice/slice_buffer.c b/src/core/lib/slice/slice_buffer.c
new file mode 100644
index 0000000000..990ef128bd
--- /dev/null
+++ b/src/core/lib/slice/slice_buffer.c
@@ -0,0 +1,284 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/slice_buffer.h>
+#include <grpc/support/port_platform.h>
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+
+/* grow a buffer; requires GRPC_SLICE_BUFFER_INLINE_ELEMENTS > 1 */
+#define GROW(x) (3 * (x) / 2)
+
+static void maybe_embiggen(grpc_slice_buffer *sb) {
+  if (sb->count == sb->capacity) {
+    sb->capacity = GROW(sb->capacity);
+    GPR_ASSERT(sb->capacity > sb->count);
+    if (sb->slices == sb->inlined) {
+      sb->slices = gpr_malloc(sb->capacity * sizeof(grpc_slice));
+      memcpy(sb->slices, sb->inlined, sb->count * sizeof(grpc_slice));
+    } else {
+      sb->slices = gpr_realloc(sb->slices, sb->capacity * sizeof(grpc_slice));
+    }
+  }
+}
+
+void grpc_slice_buffer_init(grpc_slice_buffer *sb) {
+  sb->count = 0;
+  sb->length = 0;
+  sb->capacity = GRPC_SLICE_BUFFER_INLINE_ELEMENTS;
+  sb->slices = sb->inlined;
+}
+
+void grpc_slice_buffer_destroy(grpc_slice_buffer *sb) {
+  grpc_slice_buffer_reset_and_unref(sb);
+  if (sb->slices != sb->inlined) {
+    gpr_free(sb->slices);
+  }
+}
+
+uint8_t *grpc_slice_buffer_tiny_add(grpc_slice_buffer *sb, size_t n) {
+  grpc_slice *back;
+  uint8_t *out;
+
+  sb->length += n;
+
+  if (sb->count == 0) goto add_new;
+  back = &sb->slices[sb->count - 1];
+  if (back->refcount) goto add_new;
+  if ((back->data.inlined.length + n) > sizeof(back->data.inlined.bytes))
+    goto add_new;
+  out = back->data.inlined.bytes + back->data.inlined.length;
+  back->data.inlined.length = (uint8_t)(back->data.inlined.length + n);
+  return out;
+
+add_new:
+  maybe_embiggen(sb);
+  back = &sb->slices[sb->count];
+  sb->count++;
+  back->refcount = NULL;
+  back->data.inlined.length = (uint8_t)n;
+  return back->data.inlined.bytes;
+}
+
+size_t grpc_slice_buffer_add_indexed(grpc_slice_buffer *sb, grpc_slice s) {
+  size_t out = sb->count;
+  maybe_embiggen(sb);
+  sb->slices[out] = s;
+  sb->length += GRPC_SLICE_LENGTH(s);
+  sb->count = out + 1;
+  return out;
+}
+
+void grpc_slice_buffer_add(grpc_slice_buffer *sb, grpc_slice s) {
+  size_t n = sb->count;
+  /* if both the last slice in the slice buffer and the slice being added
+     are inlined (that is, that they carry their data inside the slice data
+     structure), and the back slice is not full, then concatenate directly
+     into the back slice, preventing many small slices being passed into
+     writes */
+  if (!s.refcount && n) {
+    grpc_slice *back = &sb->slices[n - 1];
+    if (!back->refcount &&
+        back->data.inlined.length < GRPC_SLICE_INLINED_SIZE) {
+      if (s.data.inlined.length + back->data.inlined.length <=
+          GRPC_SLICE_INLINED_SIZE) {
+        memcpy(back->data.inlined.bytes + back->data.inlined.length,
+               s.data.inlined.bytes, s.data.inlined.length);
+        back->data.inlined.length =
+            (uint8_t)(back->data.inlined.length + s.data.inlined.length);
+      } else {
+        size_t cp1 = GRPC_SLICE_INLINED_SIZE - back->data.inlined.length;
+        memcpy(back->data.inlined.bytes + back->data.inlined.length,
+               s.data.inlined.bytes, cp1);
+        back->data.inlined.length = GRPC_SLICE_INLINED_SIZE;
+        maybe_embiggen(sb);
+        back = &sb->slices[n];
+        sb->count = n + 1;
+        back->refcount = NULL;
+        back->data.inlined.length = (uint8_t)(s.data.inlined.length - cp1);
+        memcpy(back->data.inlined.bytes, s.data.inlined.bytes + cp1,
+               s.data.inlined.length - cp1);
+      }
+      sb->length += s.data.inlined.length;
+      return; /* early out */
+    }
+  }
+  grpc_slice_buffer_add_indexed(sb, s);
+}
+
+void grpc_slice_buffer_addn(grpc_slice_buffer *sb, grpc_slice *s, size_t n) {
+  size_t i;
+  for (i = 0; i < n; i++) {
+    grpc_slice_buffer_add(sb, s[i]);
+  }
+}
+
+void grpc_slice_buffer_pop(grpc_slice_buffer *sb) {
+  if (sb->count != 0) {
+    size_t count = --sb->count;
+    sb->length -= GRPC_SLICE_LENGTH(sb->slices[count]);
+  }
+}
+
+void grpc_slice_buffer_reset_and_unref(grpc_slice_buffer *sb) {
+  size_t i;
+
+  for (i = 0; i < sb->count; i++) {
+    grpc_slice_unref(sb->slices[i]);
+  }
+
+  sb->count = 0;
+  sb->length = 0;
+}
+
+void grpc_slice_buffer_swap(grpc_slice_buffer *a, grpc_slice_buffer *b) {
+  GPR_SWAP(size_t, a->count, b->count);
+  GPR_SWAP(size_t, a->capacity, b->capacity);
+  GPR_SWAP(size_t, a->length, b->length);
+
+  if (a->slices == a->inlined) {
+    if (b->slices == b->inlined) {
+      /* swap contents of inlined buffer */
+      grpc_slice temp[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
+      memcpy(temp, a->slices, b->count * sizeof(grpc_slice));
+      memcpy(a->slices, b->slices, a->count * sizeof(grpc_slice));
+      memcpy(b->slices, temp, b->count * sizeof(grpc_slice));
+    } else {
+      /* a is inlined, b is not - copy a inlined into b, fix pointers */
+      a->slices = b->slices;
+      b->slices = b->inlined;
+      memcpy(b->slices, a->inlined, b->count * sizeof(grpc_slice));
+    }
+  } else if (b->slices == b->inlined) {
+    /* b is inlined, a is not - copy b inlined int a, fix pointers */
+    b->slices = a->slices;
+    a->slices = a->inlined;
+    memcpy(a->slices, b->inlined, a->count * sizeof(grpc_slice));
+  } else {
+    /* no inlining: easy swap */
+    GPR_SWAP(grpc_slice *, a->slices, b->slices);
+  }
+}
+
+void grpc_slice_buffer_move_into(grpc_slice_buffer *src,
+                                 grpc_slice_buffer *dst) {
+  /* anything to move? */
+  if (src->count == 0) {
+    return;
+  }
+  /* anything in dst? */
+  if (dst->count == 0) {
+    grpc_slice_buffer_swap(src, dst);
+    return;
+  }
+  /* both buffers have data - copy, and reset src */
+  grpc_slice_buffer_addn(dst, src->slices, src->count);
+  src->count = 0;
+  src->length = 0;
+}
+
+void grpc_slice_buffer_move_first(grpc_slice_buffer *src, size_t n,
+                                  grpc_slice_buffer *dst) {
+  size_t src_idx;
+  size_t output_len = dst->length + n;
+  size_t new_input_len = src->length - n;
+  GPR_ASSERT(src->length >= n);
+  if (src->length == n) {
+    grpc_slice_buffer_move_into(src, dst);
+    return;
+  }
+  src_idx = 0;
+  while (src_idx < src->capacity) {
+    grpc_slice slice = src->slices[src_idx];
+    size_t slice_len = GRPC_SLICE_LENGTH(slice);
+    if (n > slice_len) {
+      grpc_slice_buffer_add(dst, slice);
+      n -= slice_len;
+      src_idx++;
+    } else if (n == slice_len) {
+      grpc_slice_buffer_add(dst, slice);
+      src_idx++;
+      break;
+    } else { /* n < slice_len */
+      src->slices[src_idx] = grpc_slice_split_tail(&slice, n);
+      GPR_ASSERT(GRPC_SLICE_LENGTH(slice) == n);
+      GPR_ASSERT(GRPC_SLICE_LENGTH(src->slices[src_idx]) == slice_len - n);
+      grpc_slice_buffer_add(dst, slice);
+      break;
+    }
+  }
+  GPR_ASSERT(dst->length == output_len);
+  memmove(src->slices, src->slices + src_idx,
+          sizeof(grpc_slice) * (src->count - src_idx));
+  src->count -= src_idx;
+  src->length = new_input_len;
+  GPR_ASSERT(src->count > 0);
+}
+
+void grpc_slice_buffer_trim_end(grpc_slice_buffer *sb, size_t n,
+                                grpc_slice_buffer *garbage) {
+  GPR_ASSERT(n <= sb->length);
+  sb->length -= n;
+  for (;;) {
+    size_t idx = sb->count - 1;
+    grpc_slice slice = sb->slices[idx];
+    size_t slice_len = GRPC_SLICE_LENGTH(slice);
+    if (slice_len > n) {
+      sb->slices[idx] = grpc_slice_split_head(&slice, slice_len - n);
+      grpc_slice_buffer_add_indexed(garbage, slice);
+      return;
+    } else if (slice_len == n) {
+      grpc_slice_buffer_add_indexed(garbage, slice);
+      sb->count = idx;
+      return;
+    } else {
+      grpc_slice_buffer_add_indexed(garbage, slice);
+      n -= slice_len;
+      sb->count = idx;
+    }
+  }
+}
+
+grpc_slice grpc_slice_buffer_take_first(grpc_slice_buffer *sb) {
+  grpc_slice slice;
+  GPR_ASSERT(sb->count > 0);
+  slice = sb->slices[0];
+  memmove(&sb->slices[0], &sb->slices[1], (sb->count - 1) * sizeof(grpc_slice));
+  sb->count--;
+  sb->length -= GRPC_SLICE_LENGTH(slice);
+  return slice;
+}
diff --git a/src/core/lib/slice/slice_string_helpers.c b/src/core/lib/slice/slice_string_helpers.c
new file mode 100644
index 0000000000..4731762ece
--- /dev/null
+++ b/src/core/lib/slice/slice_string_helpers.c
@@ -0,0 +1,89 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/slice/slice_string_helpers.h"
+
+#include <string.h>
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/support/string.h"
+
+char *grpc_dump_slice(grpc_slice s, uint32_t flags) {
+  return gpr_dump((const char *)GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s),
+                  flags);
+}
+
+/** Finds the initial (\a begin) and final (\a end) offsets of the next
+ * substring from \a str + \a read_offset until the next \a sep or the end of \a
+ * str.
+ *
+ * Returns 1 and updates \a begin and \a end. Returns 0 otherwise. */
+static int slice_find_separator_offset(const grpc_slice str, const char *sep,
+                                       const size_t read_offset, size_t *begin,
+                                       size_t *end) {
+  size_t i;
+  const uint8_t *str_ptr = GRPC_SLICE_START_PTR(str) + read_offset;
+  const size_t str_len = GRPC_SLICE_LENGTH(str) - read_offset;
+  const size_t sep_len = strlen(sep);
+  if (str_len < sep_len) {
+    return 0;
+  }
+
+  for (i = 0; i <= str_len - sep_len; i++) {
+    if (memcmp(str_ptr + i, sep, sep_len) == 0) {
+      *begin = read_offset;
+      *end = read_offset + i;
+      return 1;
+    }
+  }
+  return 0;
+}
+
+void grpc_slice_split(grpc_slice str, const char *sep, grpc_slice_buffer *dst) {
+  const size_t sep_len = strlen(sep);
+  size_t begin, end;
+
+  GPR_ASSERT(sep_len > 0);
+
+  if (slice_find_separator_offset(str, sep, 0, &begin, &end) != 0) {
+    do {
+      grpc_slice_buffer_add_indexed(dst, grpc_slice_sub(str, begin, end));
+    } while (slice_find_separator_offset(str, sep, end + sep_len, &begin,
+                                         &end) != 0);
+    grpc_slice_buffer_add_indexed(
+        dst, grpc_slice_sub(str, end + sep_len, GRPC_SLICE_LENGTH(str)));
+  } else { /* no sep found, add whole input */
+    grpc_slice_buffer_add_indexed(dst, grpc_slice_ref(str));
+  }
+}
diff --git a/src/core/lib/slice/slice_string_helpers.h b/src/core/lib/slice/slice_string_helpers.h
new file mode 100644
index 0000000000..151c720777
--- /dev/null
+++ b/src/core/lib/slice/slice_string_helpers.h
@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_SLICE_SLICE_STRING_HELPERS_H
+#define GRPC_CORE_LIB_SLICE_SLICE_STRING_HELPERS_H
+
+#include <stddef.h>
+
+#include <grpc/slice.h>
+#include <grpc/slice_buffer.h>
+#include <grpc/support/port_platform.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Calls gpr_dump on a slice. */
+char *grpc_dump_slice(grpc_slice slice, uint32_t flags);
+
+/** Split \a str by the separator \a sep. Results are stored in \a dst, which
+ * should be a properly initialized instance. */
+void grpc_slice_split(grpc_slice str, const char *sep, grpc_slice_buffer *dst);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_SLICE_SLICE_STRING_HELPERS_H */