Add packet header encoding functions

lib/Makefile.am

@@ -33,10 +33,12 @@ lib_LTLIBRARIES = libngtcp2.la
 
 OBJECTS = \
 	ngtcp2_pkt.c \
-	ngtcp2_conv.c
+	ngtcp2_conv.c \
+	ngtcp2_str.c
 HFILES = \
 	ngtcp2_pkt.h \
-	ngtcp2_conv.h
+	ngtcp2_conv.h \
+	ngtcp2_str.h
 
 libngtcp2_la_SOURCES = $(HFILES) $(OBJECTS)
 libngtcp2_la_LDFLAGS = -no-undefined \

lib/ngtcp2_conv.c

@@ -30,6 +30,8 @@
 #include <arpa/inet.h>
 #endif /* HAVE_ARPA_INET_H */
 
+#include "ngtcp2_str.h"
+
 #ifdef WORDS_BIGENDIAN
 #define bwap64(N) (N)
 #else /* !WORDS_BIGENDIAN */
@@ -54,3 +56,18 @@ uint16_t ngtcp2_get_uint16(const uint8_t *p) {
   memcpy(&n, p, 2);
   return ntohs(n);
 }
+
+uint8_t *ngtcp2_put_uint64be(uint8_t *p, uint64_t n) {
+  n = bswap64(n);
+  return ngtcp2_cpymem(p, (const uint8_t *)&n, sizeof(n));
+}
+
+uint8_t *ngtcp2_put_uint32be(uint8_t *p, uint32_t n) {
+  n = htonl(n);
+  return ngtcp2_cpymem(p, (const uint8_t *)&n, sizeof(n));
+}
+
+uint8_t *ngtcp2_put_uint16be(uint8_t *p, uint16_t n) {
+  n = htons(n);
+  return ngtcp2_cpymem(p, (const uint8_t *)&n, sizeof(n));
+}

lib/ngtcp2_conv.h

@@ -52,4 +52,25 @@ uint32_t ngtcp2_get_uint32(const uint8_t *p);
  */
 uint16_t ngtcp2_get_uint16(const uint8_t *p);
 
+/*
+ * ngtcp2_put_uint64be writes |n| in host byte order in |p| in network
+ * byte order.  It returns the one beyond of the last written
+ * position.
+ */
+uint8_t *ngtcp2_put_uint64be(uint8_t *p, uint64_t n);
+
+/*
+ * ngtcp2_put_uint32be writes |n| in host byte order in |p| in network
+ * byte order.  It returns the one beyond of the last written
+ * position.
+ */
+uint8_t *ngtcp2_put_uint32be(uint8_t *p, uint32_t n);
+
+/*
+ * ngtcp2_put_uint16be writes |n| in host byte order in |p| in network
+ * byte order.  It returns the one beyond of the last written
+ * position.
+ */
+uint8_t *ngtcp2_put_uint16be(uint8_t *p, uint16_t n);
+
 #endif /* NGTCP2_CONV_H */

lib/ngtcp2_pkt.c

@@ -23,6 +23,9 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #include "ngtcp2_pkt.h"
+
+#include <assert.h>
+
 #include "ngtcp2_conv.h"
 
 ssize_t ngtcp2_pkt_decode_hd(ngtcp2_pkt_hd *dest, const uint8_t *pkt,
@@ -140,3 +143,74 @@ ssize_t ngtcp2_pkt_decode_hd_short(ngtcp2_pkt_hd *dest, const uint8_t *pkt,
 
   return (ssize_t)len;
 }
+
+ssize_t ngtcp2_pkt_encode_hd_long(uint8_t *out, size_t outlen,
+                                  const ngtcp2_pkt_hd *hd) {
+  uint8_t *p;
+
+  if (outlen < 17) {
+    return NGTCP2_ERR_INVALID_ARGUMENT;
+  }
+
+  p = out;
+
+  *p++ = NGTCP2_HEADER_FORM_MASK | hd->type;
+  p = ngtcp2_put_uint64be(p, hd->conn_id);
+  p = ngtcp2_put_uint32be(p, hd->pkt_num);
+  p = ngtcp2_put_uint32be(p, hd->version);
+
+  assert(p - out == 17);
+
+  return 17;
+}
+
+ssize_t ngtcp2_pkt_encode_hd_short(uint8_t *out, size_t outlen,
+                                   const ngtcp2_pkt_hd *hd) {
+  uint8_t *p;
+  size_t len = 1;
+  int need_conn_id;
+
+  if (hd->flags & NGTCP2_PKT_FLAG_CONN_ID) {
+    need_conn_id = 1;
+    len += 8;
+  }
+  len += hd->type;
+
+  if (outlen < len) {
+    return NGTCP2_ERR_INVALID_ARGUMENT;
+  }
+
+  p = out;
+
+  *p = hd->type;
+  if (need_conn_id) {
+    *p |= NGTCP2_CONN_ID_MASK;
+  }
+  if (hd->flags & NGTCP2_PKT_FLAG_KEY_PHASE) {
+    *p |= NGTCP2_KEY_PHASE_MASK;
+  }
+
+  ++p;
+
+  if (need_conn_id) {
+    p = ngtcp2_put_uint64be(p, hd->conn_id);
+  }
+
+  switch (hd->type) {
+  case 1:
+    *p++ = (uint8_t)hd->pkt_num;
+    break;
+  case 2:
+    p = ngtcp2_put_uint16be(p, (uint16_t)hd->pkt_num);
+    break;
+  case 3:
+    p = ngtcp2_put_uint32be(p, hd->pkt_num);
+    break;
+  default:
+    assert(0);
+  }
+
+  assert((size_t)(p - out) == len);
+
+  return p - out;
+}

lib/ngtcp2_pkt.h

@@ -66,4 +66,28 @@ ssize_t ngtcp2_pkt_decode_hd_long(ngtcp2_pkt_hd *dest, const uint8_t *pkt,
 ssize_t ngtcp2_pkt_decode_hd_short(ngtcp2_pkt_hd *dest, const uint8_t *pkt,
                                    size_t pktlen);
 
+/*
+ * ngtcp2_pkt_encode_hd_long encodes |hd| as QUIC long header into
+ * |out| which has length |outlen|.  It returns the number of bytes
+ * written into |outlen| if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGTCP2_ERR_INVALID_ARGUMENT
+ *     Buffer is too short
+ */
+ssize_t ngtcp2_pkt_encode_hd_long(uint8_t *out, size_t outlen,
+                                  const ngtcp2_pkt_hd *hd);
+
+/*
+ * ngtcp2_pkt_encode_hd_short encodes |hd| as QUIC short header into
+ * |out| which has length |outlen|.  It returns the number of bytes
+ * written into |outlen| if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGTCP2_ERR_INVALID_ARGUMENT
+ *     Buffer is too short
+ */
+ssize_t ngtcp2_pkt_encode_hd_short(uint8_t *out, size_t outlen,
+                                   const ngtcp2_pkt_hd *hd);
+
 #endif /* NGTCP2_PKT_H */

lib/ngtcp2_str.c

+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2017 ngtcp2 contributors
+ *
+ * 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.
+ */
+#include "ngtcp2_str.h"
+
+#include <string.h>
+
+uint8_t *ngtcp2_cpymem(uint8_t *dest, const uint8_t *src, size_t n) {
+  memcpy(dest, src, n);
+  return dest + n;
+}

lib/ngtcp2_str.h

+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2017 ngtcp2 contributors
+ *
+ * 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 NGTCP2_STR_H
+#define NGTCP2_STR_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <ngtcp2/ngtcp2.h>
+
+uint8_t *ngtcp2_cpymem(uint8_t *dest, const uint8_t *src, size_t n);
+
+#endif /* NGTCP2_STR_H */