Adding upstream version 1.52.0.upstream/1.52.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 716 insertions, 0 deletions

diff --git a/bpf/CMakeLists.txt b/bpf/CMakeLists.txt
new file mode 100644
index 0000000..904b821
--- /dev/null
+++ b/bpf/CMakeLists.txt
@@ -0,0 +1,13 @@
+if(LIBBPF_FOUND)
+  add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/reuseport_kern.o"
+    COMMAND ${CMAKE_C_COMPILER} ${BPFCFLAGS} ${EXTRABPFCFLAGS} -I${LIBBPF_INCLUDE_DIRS} -target bpf -c reuseport_kern.c -o "${CMAKE_CURRENT_BINARY_DIR}/reuseport_kern.o"
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+    VERBATIM)
+
+  add_custom_target(bpf ALL
+    DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/reuseport_kern.o"
+    VERBATIM)
+
+  install(FILES "${CMAKE_CURRENT_BINARY_DIR}/reuseport_kern.o"
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/${CMAKE_PROJECT_NAME}")
+endif()
diff --git a/bpf/Makefile.am b/bpf/Makefile.am
new file mode 100644
index 0000000..9017fd9
--- /dev/null
+++ b/bpf/Makefile.am
@@ -0,0 +1,40 @@
+# nghttp2 - HTTP/2 C Library
+
+# Copyright (c) 2021 Tatsuhiro Tsujikawa
+
+# 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.
+
+EXTRA_DIST = CMakeLists.txt reuseport_kern.c
+
+if HAVE_LIBBPF
+
+bpf_pkglibdir = $(pkglibdir)
+bpf_pkglib_DATA = reuseport_kern.o
+
+all: $(builddir)/reuseport_kern.o
+
+$(builddir)/reuseport_kern.o: reuseport_kern.c
+	$(CC) @LIBBPF_CFLAGS@ @BPFCFLAGS@ @EXTRABPFCFLAGS@ \
+	  -target bpf -c $< -o $@
+
+clean-local:
+	-rm -f reuseport_kern.o
+
+endif # HAVE_LIBBPF
diff --git a/bpf/reuseport_kern.c b/bpf/reuseport_kern.c
new file mode 100644
index 0000000..74c08c5
--- /dev/null
+++ b/bpf/reuseport_kern.c
@@ -0,0 +1,663 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2021 Tatsuhiro Tsujikawa
+ *
+ * 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 <linux/udp.h>
+#include <linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+
+/*
+ * How to compile:
+ *
+ * clang-12 -O2 -Wall -target bpf -g -c reuseport_kern.c -o reuseport_kern.o \
+ *   -I/path/to/kernel/include
+ *
+ * See
+ * https://www.kernel.org/doc/Documentation/kbuild/headers_install.txt
+ * how to install kernel header files.
+ */
+
+/* AES_CBC_decrypt_buffer: https://github.com/kokke/tiny-AES-c
+   License is Public Domain.  Commit hash:
+   12e7744b4919e9d55de75b7ab566326a1c8e7a67 */
+
+#define AES_BLOCKLEN                                                           \
+  16 /* Block length in bytes - AES is 128b block                              \
+        only */
+
+#define AES_KEYLEN 16 /* Key length in bytes */
+#define AES_keyExpSize 176
+
+struct AES_ctx {
+  __u8 RoundKey[AES_keyExpSize];
+};
+
+/* The number of columns comprising a state in AES. This is a constant
+   in AES. Value=4 */
+#define Nb 4
+
+#define Nk 4  /* The number of 32 bit words in a key. */
+#define Nr 10 /* The number of rounds in AES Cipher. */
+
+/* state - array holding the intermediate results during
+   decryption. */
+typedef __u8 state_t[4][4];
+
+/* The lookup-tables are marked const so they can be placed in
+   read-only storage instead of RAM The numbers below can be computed
+   dynamically trading ROM for RAM - This can be useful in (embedded)
+   bootloader applications, where ROM is often limited. */
+static const __u8 sbox[256] = {
+    /* 0 1 2 3 4 5 6 7 8 9 A B C D E F */
+    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b,
+    0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,
+    0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26,
+    0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
+    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2,
+    0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,
+    0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed,
+    0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
+    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f,
+    0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,
+    0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec,
+    0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
+    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14,
+    0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,
+    0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d,
+    0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
+    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f,
+    0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,
+    0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11,
+    0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
+    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f,
+    0xb0, 0x54, 0xbb, 0x16};
+
+static const __u8 rsbox[256] = {
+    0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e,
+    0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87,
+    0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, 0x54, 0x7b, 0x94, 0x32,
+    0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
+    0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49,
+    0x6d, 0x8b, 0xd1, 0x25, 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16,
+    0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, 0x6c, 0x70, 0x48, 0x50,
+    0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
+    0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05,
+    0xb8, 0xb3, 0x45, 0x06, 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02,
+    0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, 0x3a, 0x91, 0x11, 0x41,
+    0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
+    0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8,
+    0x1c, 0x75, 0xdf, 0x6e, 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89,
+    0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, 0xfc, 0x56, 0x3e, 0x4b,
+    0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
+    0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59,
+    0x27, 0x80, 0xec, 0x5f, 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d,
+    0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 0x3b, 0x4d,
+    0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
+    0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63,
+    0x55, 0x21, 0x0c, 0x7d};
+
+/* The round constant word array, Rcon[i], contains the values given
+   by x to the power (i-1) being powers of x (x is denoted as {02}) in
+   the field GF(2^8) */
+static const __u8 Rcon[11] = {0x8d, 0x01, 0x02, 0x04, 0x08, 0x10,
+                              0x20, 0x40, 0x80, 0x1b, 0x36};
+
+#define getSBoxValue(num) (sbox[(num)])
+
+/* This function produces Nb(Nr+1) round keys. The round keys are used
+   in each round to decrypt the states. */
+static void KeyExpansion(__u8 *RoundKey, const __u8 *Key) {
+  unsigned i, j, k;
+  __u8 tempa[4]; /* Used for the column/row operations */
+
+  /* The first round key is the key itself. */
+  for (i = 0; i < Nk; ++i) {
+    RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
+    RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
+    RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
+    RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
+  }
+
+  /* All other round keys are found from the previous round keys. */
+  for (i = Nk; i < Nb * (Nr + 1); ++i) {
+    {
+      k = (i - 1) * 4;
+      tempa[0] = RoundKey[k + 0];
+      tempa[1] = RoundKey[k + 1];
+      tempa[2] = RoundKey[k + 2];
+      tempa[3] = RoundKey[k + 3];
+    }
+
+    if (i % Nk == 0) {
+      /* This function shifts the 4 bytes in a word to the left once.
+         [a0,a1,a2,a3] becomes [a1,a2,a3,a0] */
+
+      /* Function RotWord() */
+      {
+        const __u8 u8tmp = tempa[0];
+        tempa[0] = tempa[1];
+        tempa[1] = tempa[2];
+        tempa[2] = tempa[3];
+        tempa[3] = u8tmp;
+      }
+
+      /* SubWord() is a function that takes a four-byte input word and
+         applies the S-box to each of the four bytes to produce an
+         output word. */
+
+      /* Function Subword() */
+      {
+        tempa[0] = getSBoxValue(tempa[0]);
+        tempa[1] = getSBoxValue(tempa[1]);
+        tempa[2] = getSBoxValue(tempa[2]);
+        tempa[3] = getSBoxValue(tempa[3]);
+      }
+
+      tempa[0] = tempa[0] ^ Rcon[i / Nk];
+    }
+    j = i * 4;
+    k = (i - Nk) * 4;
+    RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];
+    RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];
+    RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];
+    RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];
+  }
+}
+
+static void AES_init_ctx(struct AES_ctx *ctx, const __u8 *key) {
+  KeyExpansion(ctx->RoundKey, key);
+}
+
+/* This function adds the round key to state.  The round key is added
+   to the state by an XOR function. */
+static void AddRoundKey(__u8 round, state_t *state, const __u8 *RoundKey) {
+  __u8 i, j;
+  for (i = 0; i < 4; ++i) {
+    for (j = 0; j < 4; ++j) {
+      (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
+    }
+  }
+}
+
+static __u8 xtime(__u8 x) { return ((x << 1) ^ (((x >> 7) & 1) * 0x1b)); }
+
+#define Multiply(x, y)                                                         \
+  (((y & 1) * x) ^ ((y >> 1 & 1) * xtime(x)) ^                                 \
+   ((y >> 2 & 1) * xtime(xtime(x))) ^                                          \
+   ((y >> 3 & 1) * xtime(xtime(xtime(x)))) ^                                   \
+   ((y >> 4 & 1) * xtime(xtime(xtime(xtime(x))))))
+
+#define getSBoxInvert(num) (rsbox[(num)])
+
+/* MixColumns function mixes the columns of the state matrix.  The
+   method used to multiply may be difficult to understand for the
+   inexperienced. Please use the references to gain more
+   information. */
+static void InvMixColumns(state_t *state) {
+  int i;
+  __u8 a, b, c, d;
+  for (i = 0; i < 4; ++i) {
+    a = (*state)[i][0];
+    b = (*state)[i][1];
+    c = (*state)[i][2];
+    d = (*state)[i][3];
+
+    (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^
+                     Multiply(d, 0x09);
+    (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^
+                     Multiply(d, 0x0d);
+    (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^
+                     Multiply(d, 0x0b);
+    (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^
+                     Multiply(d, 0x0e);
+  }
+}
+
+extern __u32 LINUX_KERNEL_VERSION __kconfig;
+
+/* The SubBytes Function Substitutes the values in the state matrix
+   with values in an S-box. */
+static void InvSubBytes(state_t *state) {
+  __u8 i, j;
+  if (LINUX_KERNEL_VERSION < KERNEL_VERSION(5, 10, 0)) {
+    for (i = 0; i < 4; ++i) {
+      for (j = 0; j < 4; ++j) {
+        /* Ubuntu 20.04 LTS kernel 5.4.0 needs this workaround
+           otherwise "math between map_value pointer and register with
+           unbounded min value is not allowed".  5.10.0 is a kernel
+           version that works but it might not be the minimum
+           version.  */
+        __u8 k = (*state)[j][i];
+        (*state)[j][i] = k ? getSBoxInvert(k) : getSBoxInvert(0);
+      }
+    }
+  } else {
+    for (i = 0; i < 4; ++i) {
+      for (j = 0; j < 4; ++j) {
+        (*state)[j][i] = getSBoxInvert((*state)[j][i]);
+      }
+    }
+  }
+}
+
+static void InvShiftRows(state_t *state) {
+  __u8 temp;
+
+  /* Rotate first row 1 columns to right */
+  temp = (*state)[3][1];
+  (*state)[3][1] = (*state)[2][1];
+  (*state)[2][1] = (*state)[1][1];
+  (*state)[1][1] = (*state)[0][1];
+  (*state)[0][1] = temp;
+
+  /* Rotate second row 2 columns to right */
+  temp = (*state)[0][2];
+  (*state)[0][2] = (*state)[2][2];
+  (*state)[2][2] = temp;
+
+  temp = (*state)[1][2];
+  (*state)[1][2] = (*state)[3][2];
+  (*state)[3][2] = temp;
+
+  /* Rotate third row 3 columns to right */
+  temp = (*state)[0][3];
+  (*state)[0][3] = (*state)[1][3];
+  (*state)[1][3] = (*state)[2][3];
+  (*state)[2][3] = (*state)[3][3];
+  (*state)[3][3] = temp;
+}
+
+static void InvCipher(state_t *state, const __u8 *RoundKey) {
+  /* Add the First round key to the state before starting the
+     rounds. */
+  AddRoundKey(Nr, state, RoundKey);
+
+  /* There will be Nr rounds.  The first Nr-1 rounds are identical.
+     These Nr rounds are executed in the loop below.  Last one without
+     InvMixColumn() */
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 1, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 2, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 3, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 4, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 5, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 6, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 7, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 8, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 9, state, RoundKey);
+  InvMixColumns(state);
+
+  InvShiftRows(state);
+  InvSubBytes(state);
+  AddRoundKey(Nr - 10, state, RoundKey);
+}
+
+static void AES_ECB_decrypt(const struct AES_ctx *ctx, __u8 *buf) {
+  /* The next function call decrypts the PlainText with the Key using
+     AES algorithm. */
+  InvCipher((state_t *)buf, ctx->RoundKey);
+}
+
+/* rol32: From linux kernel source code */
+
+/**
+ * rol32 - rotate a 32-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u32 rol32(__u32 word, unsigned int shift) {
+  return (word << shift) | (word >> ((-shift) & 31));
+}
+
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * https://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup3.c, by Bob Jenkins, May 2006, Public Domain.
+ *
+ * These are functions for producing 32-bit hashes for hash table lookup.
+ * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
+ * are externally useful functions.  Routines to test the hash are included
+ * if SELF_TEST is defined.  You can use this free for any purpose.  It's in
+ * the public domain.  It has no warranty.
+ *
+ * Copyright (C) 2009-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
+ *
+ * I've modified Bob's hash to be useful in the Linux kernel, and
+ * any bugs present are my fault.
+ * Jozsef
+ */
+
+/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
+#define __jhash_final(a, b, c)                                                 \
+  {                                                                            \
+    c ^= b;                                                                    \
+    c -= rol32(b, 14);                                                         \
+    a ^= c;                                                                    \
+    a -= rol32(c, 11);                                                         \
+    b ^= a;                                                                    \
+    b -= rol32(a, 25);                                                         \
+    c ^= b;                                                                    \
+    c -= rol32(b, 16);                                                         \
+    a ^= c;                                                                    \
+    a -= rol32(c, 4);                                                          \
+    b ^= a;                                                                    \
+    b -= rol32(a, 14);                                                         \
+    c ^= b;                                                                    \
+    c -= rol32(b, 24);                                                         \
+  }
+
+/* __jhash_nwords - hash exactly 3, 2 or 1 word(s) */
+static inline __u32 __jhash_nwords(__u32 a, __u32 b, __u32 c, __u32 initval) {
+  a += initval;
+  b += initval;
+  c += initval;
+
+  __jhash_final(a, b, c);
+
+  return c;
+}
+
+/* An arbitrary initial parameter */
+#define JHASH_INITVAL 0xdeadbeef
+
+static inline __u32 jhash_2words(__u32 a, __u32 b, __u32 initval) {
+  return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
+}
+
+struct {
+  __uint(type, BPF_MAP_TYPE_HASH);
+  __uint(max_entries, 255);
+  __type(key, __u64);
+  __type(value, __u32);
+} cid_prefix_map SEC(".maps");
+
+struct {
+  __uint(type, BPF_MAP_TYPE_REUSEPORT_SOCKARRAY);
+  __uint(max_entries, 255);
+  __type(key, __u32);
+  __type(value, __u32);
+} reuseport_array SEC(".maps");
+
+struct {
+  __uint(type, BPF_MAP_TYPE_ARRAY);
+  __uint(max_entries, 3);
+  __type(key, __u32);
+  __type(value, __u64);
+} sk_info SEC(".maps");
+
+typedef struct quic_hd {
+  __u8 *dcid;
+  __u32 dcidlen;
+  __u32 dcid_offset;
+  __u8 type;
+} quic_hd;
+
+#define SV_DCIDLEN 20
+#define MAX_DCIDLEN 20
+#define MIN_DCIDLEN 8
+#define CID_PREFIXLEN 8
+#define CID_PREFIX_OFFSET 1
+
+enum {
+  NGTCP2_PKT_INITIAL = 0x0,
+  NGTCP2_PKT_0RTT = 0x1,
+  NGTCP2_PKT_HANDSHAKE = 0x2,
+  NGTCP2_PKT_SHORT = 0x40,
+};
+
+static inline int parse_quic(quic_hd *qhd, __u8 *data, __u8 *data_end) {
+  __u8 *p;
+  __u64 dcidlen;
+
+  if (*data & 0x80) {
+    p = data + 1 + 4;
+
+    /* Do not check the actual DCID length because we might not buffer
+       entire DCID here. */
+    dcidlen = *p;
+
+    if (dcidlen > MAX_DCIDLEN || dcidlen < MIN_DCIDLEN) {
+      return -1;
+    }
+
+    ++p;
+
+    qhd->type = (*data & 0x30) >> 4;
+    qhd->dcid = p;
+    qhd->dcidlen = dcidlen;
+    qhd->dcid_offset = 6;
+  } else {
+    qhd->type = NGTCP2_PKT_SHORT;
+    qhd->dcid = data + 1;
+    qhd->dcidlen = SV_DCIDLEN;
+    qhd->dcid_offset = 1;
+  }
+
+  return 0;
+}
+
+static __u32 hash(const __u8 *data, __u32 datalen, __u32 initval) {
+  __u32 a, b;
+
+  a = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
+  b = (data[4] << 24) | (data[5] << 16) | (data[6] << 8) | data[7];
+
+  return jhash_2words(a, b, initval);
+}
+
+static __u32 sk_index_from_dcid(const quic_hd *qhd,
+                                const struct sk_reuseport_md *reuse_md,
+                                __u64 num_socks) {
+  __u32 len = qhd->dcidlen;
+  __u32 h = reuse_md->hash;
+  __u8 hbuf[8];
+
+  if (len > 16) {
+    __builtin_memset(hbuf, 0, sizeof(hbuf));
+
+    switch (len) {
+    case 20:
+      __builtin_memcpy(hbuf, qhd->dcid + 16, 4);
+      break;
+    case 19:
+      __builtin_memcpy(hbuf, qhd->dcid + 16, 3);
+      break;
+    case 18:
+      __builtin_memcpy(hbuf, qhd->dcid + 16, 2);
+      break;
+    case 17:
+      __builtin_memcpy(hbuf, qhd->dcid + 16, 1);
+      break;
+    }
+
+    h = hash(hbuf, sizeof(hbuf), h);
+    len = 16;
+  }
+
+  if (len > 8) {
+    __builtin_memset(hbuf, 0, sizeof(hbuf));
+
+    switch (len) {
+    case 16:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 8);
+      break;
+    case 15:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 7);
+      break;
+    case 14:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 6);
+      break;
+    case 13:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 5);
+      break;
+    case 12:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 4);
+      break;
+    case 11:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 3);
+      break;
+    case 10:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 2);
+      break;
+    case 9:
+      __builtin_memcpy(hbuf, qhd->dcid + 8, 1);
+      break;
+    }
+
+    h = hash(hbuf, sizeof(hbuf), h);
+    len = 8;
+  }
+
+  return hash(qhd->dcid, len, h) % num_socks;
+}
+
+SEC("sk_reuseport")
+int select_reuseport(struct sk_reuseport_md *reuse_md) {
+  __u32 sk_index, *psk_index;
+  __u64 *pnum_socks, *pkey;
+  __u32 zero = 0, key_high_idx = 1, key_low_idx = 2;
+  int rv;
+  quic_hd qhd;
+  __u8 qpktbuf[6 + MAX_DCIDLEN];
+  struct AES_ctx aes_ctx;
+  __u8 key[AES_KEYLEN];
+  __u8 *cid_prefix;
+
+  if (bpf_skb_load_bytes(reuse_md, sizeof(struct udphdr), qpktbuf,
+                         sizeof(qpktbuf)) != 0) {
+    return SK_DROP;
+  }
+
+  pnum_socks = bpf_map_lookup_elem(&sk_info, &zero);
+  if (pnum_socks == NULL) {
+    return SK_DROP;
+  }
+
+  pkey = bpf_map_lookup_elem(&sk_info, &key_high_idx);
+  if (pkey == NULL) {
+    return SK_DROP;
+  }
+
+  __builtin_memcpy(key, pkey, sizeof(*pkey));
+
+  pkey = bpf_map_lookup_elem(&sk_info, &key_low_idx);
+  if (pkey == NULL) {
+    return SK_DROP;
+  }
+
+  __builtin_memcpy(key + sizeof(*pkey), pkey, sizeof(*pkey));
+
+  rv = parse_quic(&qhd, qpktbuf, qpktbuf + sizeof(qpktbuf));
+  if (rv != 0) {
+    return SK_DROP;
+  }
+
+  AES_init_ctx(&aes_ctx, key);
+
+  switch (qhd.type) {
+  case NGTCP2_PKT_INITIAL:
+  case NGTCP2_PKT_0RTT:
+    if (qhd.dcidlen == SV_DCIDLEN) {
+      cid_prefix = qhd.dcid + CID_PREFIX_OFFSET;
+      AES_ECB_decrypt(&aes_ctx, cid_prefix);
+
+      psk_index = bpf_map_lookup_elem(&cid_prefix_map, cid_prefix);
+      if (psk_index != NULL) {
+        sk_index = *psk_index;
+
+        break;
+      }
+    }
+
+    sk_index = sk_index_from_dcid(&qhd, reuse_md, *pnum_socks);
+
+    break;
+  case NGTCP2_PKT_HANDSHAKE:
+  case NGTCP2_PKT_SHORT:
+    if (qhd.dcidlen != SV_DCIDLEN) {
+      return SK_DROP;
+    }
+
+    cid_prefix = qhd.dcid + CID_PREFIX_OFFSET;
+    AES_ECB_decrypt(&aes_ctx, cid_prefix);
+
+    psk_index = bpf_map_lookup_elem(&cid_prefix_map, cid_prefix);
+    if (psk_index == NULL) {
+      sk_index = sk_index_from_dcid(&qhd, reuse_md, *pnum_socks);
+
+      break;
+    }
+
+    sk_index = *psk_index;
+
+    break;
+  default:
+    return SK_DROP;
+  }
+
+  rv = bpf_sk_select_reuseport(reuse_md, &reuseport_array, &sk_index, 0);
+  if (rv != 0) {
+    return SK_DROP;
+  }
+
+  return SK_PASS;
+}