diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c | 102 |
1 files changed, 62 insertions, 40 deletions
diff --git a/tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c b/tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c index 07d786329105..62b8e29ced9f 100644 --- a/tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c +++ b/tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c @@ -1,12 +1,15 @@ // SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause /* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */ +#define BPF_NO_KFUNC_PROTOTYPES #include "vmlinux.h" #include <bpf/bpf_helpers.h> #include <bpf/bpf_endian.h> #include <asm/errno.h> +#include "bpf_compiler.h" + #define TC_ACT_OK 0 #define TC_ACT_SHOT 2 @@ -18,7 +21,6 @@ #define tcp_flag_word(tp) (((union tcp_word_hdr *)(tp))->words[3]) -#define IP_DF 0x4000 #define IP_MF 0x2000 #define IP_OFFSET 0x1fff @@ -53,6 +55,8 @@ #define DEFAULT_TTL 64 #define MAX_ALLOWED_PORTS 8 +#define MAX_PACKET_OFF 0xffff + #define swap(a, b) \ do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) @@ -149,11 +153,11 @@ static __always_inline __u16 csum_ipv6_magic(const struct in6_addr *saddr, __u64 sum = csum; int i; -#pragma unroll + __pragma_loop_unroll for (i = 0; i < 4; i++) sum += (__u32)saddr->in6_u.u6_addr32[i]; -#pragma unroll + __pragma_loop_unroll for (i = 0; i < 4; i++) sum += (__u32)daddr->in6_u.u6_addr32[i]; @@ -177,69 +181,82 @@ static __always_inline __u32 tcp_ns_to_ts(__u64 ns) return ns / (NSEC_PER_SEC / TCP_TS_HZ); } -static __always_inline __u32 tcp_time_stamp_raw(void) +static __always_inline __u32 tcp_clock_ms(void) { return tcp_ns_to_ts(tcp_clock_ns()); } struct tcpopt_context { - __u8 *ptr; - __u8 *end; + void *data; void *data_end; __be32 *tsecr; __u8 wscale; bool option_timestamp; bool option_sack; + __u32 off; }; -static int tscookie_tcpopt_parse(struct tcpopt_context *ctx) +static __always_inline u8 *next(struct tcpopt_context *ctx, __u32 sz) { - __u8 opcode, opsize; + __u64 off = ctx->off; + __u8 *data; - if (ctx->ptr >= ctx->end) - return 1; - if (ctx->ptr >= ctx->data_end) - return 1; + /* Verifier forbids access to packet when offset exceeds MAX_PACKET_OFF */ + if (off > MAX_PACKET_OFF - sz) + return NULL; - opcode = ctx->ptr[0]; + data = ctx->data + off; + barrier_var(data); + if (data + sz >= ctx->data_end) + return NULL; - if (opcode == TCPOPT_EOL) - return 1; - if (opcode == TCPOPT_NOP) { - ++ctx->ptr; - return 0; - } + ctx->off += sz; + return data; +} - if (ctx->ptr + 1 >= ctx->end) - return 1; - if (ctx->ptr + 1 >= ctx->data_end) +static int tscookie_tcpopt_parse(struct tcpopt_context *ctx) +{ + __u8 *opcode, *opsize, *wscale, *tsecr; + __u32 off = ctx->off; + + opcode = next(ctx, 1); + if (!opcode) return 1; - opsize = ctx->ptr[1]; - if (opsize < 2) + + if (*opcode == TCPOPT_EOL) return 1; + if (*opcode == TCPOPT_NOP) + return 0; - if (ctx->ptr + opsize > ctx->end) + opsize = next(ctx, 1); + if (!opsize || *opsize < 2) return 1; - switch (opcode) { + switch (*opcode) { case TCPOPT_WINDOW: - if (opsize == TCPOLEN_WINDOW && ctx->ptr + TCPOLEN_WINDOW <= ctx->data_end) - ctx->wscale = ctx->ptr[2] < TCP_MAX_WSCALE ? ctx->ptr[2] : TCP_MAX_WSCALE; + wscale = next(ctx, 1); + if (!wscale) + return 1; + if (*opsize == TCPOLEN_WINDOW) + ctx->wscale = *wscale < TCP_MAX_WSCALE ? *wscale : TCP_MAX_WSCALE; break; case TCPOPT_TIMESTAMP: - if (opsize == TCPOLEN_TIMESTAMP && ctx->ptr + TCPOLEN_TIMESTAMP <= ctx->data_end) { + tsecr = next(ctx, 4); + if (!tsecr) + return 1; + if (*opsize == TCPOLEN_TIMESTAMP) { ctx->option_timestamp = true; /* Client's tsval becomes our tsecr. */ - *ctx->tsecr = get_unaligned((__be32 *)(ctx->ptr + 2)); + *ctx->tsecr = get_unaligned((__be32 *)tsecr); } break; case TCPOPT_SACK_PERM: - if (opsize == TCPOLEN_SACK_PERM) + if (*opsize == TCPOLEN_SACK_PERM) ctx->option_sack = true; break; } - ctx->ptr += opsize; + ctx->off = off + *opsize; return 0; } @@ -256,16 +273,21 @@ static int tscookie_tcpopt_parse_batch(__u32 index, void *context) static __always_inline bool tscookie_init(struct tcphdr *tcp_header, __u16 tcp_len, __be32 *tsval, - __be32 *tsecr, void *data_end) + __be32 *tsecr, void *data, void *data_end) { struct tcpopt_context loop_ctx = { - .ptr = (__u8 *)(tcp_header + 1), - .end = (__u8 *)tcp_header + tcp_len, + .data = data, .data_end = data_end, .tsecr = tsecr, .wscale = TS_OPT_WSCALE_MASK, .option_timestamp = false, .option_sack = false, + /* Note: currently verifier would track .off as unbound scalar. + * In case if verifier would at some point get smarter and + * compute bounded value for this var, beware that it might + * hinder bpf_loop() convergence validation. + */ + .off = (__u8 *)(tcp_header + 1) - (__u8 *)data, }; u32 cookie; @@ -274,7 +296,7 @@ static __always_inline bool tscookie_init(struct tcphdr *tcp_header, if (!loop_ctx.option_timestamp) return false; - cookie = tcp_time_stamp_raw() & ~TSMASK; + cookie = tcp_clock_ms() & ~TSMASK; cookie |= loop_ctx.wscale & TS_OPT_WSCALE_MASK; if (loop_ctx.option_sack) cookie |= TS_OPT_SACK; @@ -419,7 +441,7 @@ static __always_inline int tcp_lookup(void *ctx, struct header_pointers *hdr, bo /* TCP doesn't normally use fragments, and XDP can't reassemble * them. */ - if ((hdr->ipv4->frag_off & bpf_htons(IP_DF | IP_MF | IP_OFFSET)) != bpf_htons(IP_DF)) + if ((hdr->ipv4->frag_off & bpf_htons(IP_MF | IP_OFFSET)) != 0) return XDP_DROP; tup.ipv4.saddr = hdr->ipv4->saddr; @@ -447,13 +469,13 @@ static __always_inline int tcp_lookup(void *ctx, struct header_pointers *hdr, bo unsigned long status = ct->status; bpf_ct_release(ct); - if (status & IPS_CONFIRMED_BIT) + if (status & IPS_CONFIRMED) return XDP_PASS; } else if (ct_lookup_opts.error != -ENOENT) { return XDP_ABORTED; } - /* error == -ENOENT || !(status & IPS_CONFIRMED_BIT) */ + /* error == -ENOENT || !(status & IPS_CONFIRMED) */ return XDP_TX; } @@ -635,7 +657,7 @@ static __always_inline int syncookie_handle_syn(struct header_pointers *hdr, cookie = (__u32)value; if (tscookie_init((void *)hdr->tcp, hdr->tcp_len, - &tsopt_buf[0], &tsopt_buf[1], data_end)) + &tsopt_buf[0], &tsopt_buf[1], data, data_end)) tsopt = tsopt_buf; /* Check that there is enough space for a SYNACK. It also covers |
