/* * 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 #include #include #include /* * 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); } } /* 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; for (i = 0; i < 4; ++i) { for (j = 0; j < 4; ++j) { #if LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0) /* 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 a minimum version. */ __u8 k = (*state)[j][i]; (*state)[j][i] = k ? getSBoxInvert(k) : getSBoxInvert(0); #else /* !(LINUX_VERSION_CDOE < KERNEL_VERSION(5, 10, 0)) */ (*state)[j][i] = getSBoxInvert((*state)[j][i]); #endif /* !(LINUX_VERSION_CDOE < KERNEL_VERSION(5, 10, 0)) */ } } } 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 bpf_map_def SEC("maps") cid_prefix_map = { .type = BPF_MAP_TYPE_HASH, .max_entries = 255, .key_size = sizeof(__u64), .value_size = sizeof(__u32), }; struct bpf_map_def SEC("maps") reuseport_array = { .type = BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, .max_entries = 255, .key_size = sizeof(__u32), .value_size = sizeof(__u32), }; struct bpf_map_def SEC("maps") sk_info = { .type = BPF_MAP_TYPE_ARRAY, .max_entries = 3, .key_size = sizeof(__u32), .value_size = sizeof(__u64), }; 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 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]; 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) { AES_ECB_decrypt(&aes_ctx, qhd.dcid); psk_index = bpf_map_lookup_elem(&cid_prefix_map, qhd.dcid); 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; } AES_ECB_decrypt(&aes_ctx, qhd.dcid); psk_index = bpf_map_lookup_elem(&cid_prefix_map, qhd.dcid); 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; }