From 8b614aebecdf2b1f72d51b1527f5a75d218b78e2 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 17 Dec 2015 23:51:54 +0100 Subject: bpf: move clearing of A/X into classic to eBPF migration prologue Back in the days where eBPF (or back then "internal BPF" ;->) was not exposed to user space, and only the classic BPF programs internally translated into eBPF programs, we missed the fact that for classic BPF A and X needed to be cleared. It was fixed back then via 83d5b7ef99c9 ("net: filter: initialize A and X registers"), and thus classic BPF specifics were added to the eBPF interpreter core to work around it. This added some confusion for JIT developers later on that take the eBPF interpreter code as an example for deriving their JIT. F.e. in f75298f5c3fe ("s390/bpf: clear correct BPF accumulator register"), at least X could leak stack memory. Furthermore, since this is only needed for classic BPF translations and not for eBPF (verifier takes care that read access to regs cannot be done uninitialized), more complexity is added to JITs as they need to determine whether they deal with migrations or native eBPF where they can just omit clearing A/X in their prologue and thus reduce image size a bit, see f.e. cde66c2d88da ("s390/bpf: Only clear A and X for converted BPF programs"). In other cases (x86, arm64), A and X is being cleared in the prologue also for eBPF case, which is unnecessary. Lets move this into the BPF migration in bpf_convert_filter() where it actually belongs as long as the number of eBPF JITs are still few. It can thus be done generically; allowing us to remove the quirk from __bpf_prog_run() and to slightly reduce JIT image size in case of eBPF, while reducing code duplication on this matter in current(/future) eBPF JITs. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Reviewed-by: Michael Holzheu Tested-by: Michael Holzheu Cc: Zi Shen Lim Cc: Yang Shi Acked-by: Yang Shi Acked-by: Zi Shen Lim Signed-off-by: David S. Miller --- arch/s390/net/bpf_jit_comp.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 9a0c4c22e536..3c0bfc1f2694 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -408,7 +408,7 @@ static void emit_load_skb_data_hlen(struct bpf_jit *jit) * Save registers and create stack frame if necessary. * See stack frame layout desription in "bpf_jit.h"! */ -static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic) +static void bpf_jit_prologue(struct bpf_jit *jit) { if (jit->seen & SEEN_TAIL_CALL) { /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */ @@ -448,15 +448,6 @@ static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic) /* stg %b1,ST_OFF_SKBP(%r0,%r15) */ EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_SKBP); - /* Clear A (%b0) and X (%b7) registers for converted BPF programs */ - if (is_classic) { - if (REG_SEEN(BPF_REG_A)) - /* lghi %ba,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_A, 0); - if (REG_SEEN(BPF_REG_X)) - /* lghi %bx,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_X, 0); - } } /* @@ -1245,7 +1236,7 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) jit->lit = jit->lit_start; jit->prg = 0; - bpf_jit_prologue(jit, bpf_prog_was_classic(fp)); + bpf_jit_prologue(jit); for (i = 0; i < fp->len; i += insn_count) { insn_count = bpf_jit_insn(jit, fp, i); if (insn_count < 0) -- cgit v1.2.3 From 538950a1b7527a0a52ccd9337e3fcd304f027f13 Mon Sep 17 00:00:00 2001 From: Craig Gallek Date: Mon, 4 Jan 2016 17:41:47 -0500 Subject: soreuseport: setsockopt SO_ATTACH_REUSEPORT_[CE]BPF Expose socket options for setting a classic or extended BPF program for use when selecting sockets in an SO_REUSEPORT group. These options can be used on the first socket to belong to a group before bind or on any socket in the group after bind. This change includes refactoring of the existing sk_filter code to allow reuse of the existing BPF filter validation checks. Signed-off-by: Craig Gallek Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- arch/alpha/include/uapi/asm/socket.h | 3 + arch/avr32/include/uapi/asm/socket.h | 3 + arch/frv/include/uapi/asm/socket.h | 3 + arch/ia64/include/uapi/asm/socket.h | 3 + arch/m32r/include/uapi/asm/socket.h | 3 + arch/mips/include/uapi/asm/socket.h | 3 + arch/mn10300/include/uapi/asm/socket.h | 3 + arch/parisc/include/uapi/asm/socket.h | 3 + arch/powerpc/include/uapi/asm/socket.h | 3 + arch/s390/include/uapi/asm/socket.h | 3 + arch/sparc/include/uapi/asm/socket.h | 3 + arch/xtensa/include/uapi/asm/socket.h | 3 + include/linux/filter.h | 2 + include/net/sock_reuseport.h | 10 ++- include/net/udp.h | 5 +- include/uapi/asm-generic/socket.h | 3 + net/core/filter.c | 121 +++++++++++++++++++++++++++------ net/core/sock.c | 29 ++++++++ net/core/sock_reuseport.c | 88 ++++++++++++++++++++++-- net/ipv4/udp.c | 14 ++-- net/ipv4/udp_diag.c | 4 +- net/ipv6/udp.c | 14 ++-- 22 files changed, 282 insertions(+), 44 deletions(-) (limited to 'arch/s390') diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 9a20821b111c..c5fb9e6bc3a5 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -92,4 +92,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/avr32/include/uapi/asm/socket.h b/arch/avr32/include/uapi/asm/socket.h index 2b65ed6b277c..9de0796240a0 100644 --- a/arch/avr32/include/uapi/asm/socket.h +++ b/arch/avr32/include/uapi/asm/socket.h @@ -85,4 +85,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _UAPI__ASM_AVR32_SOCKET_H */ diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h index 4823ad125578..f02e4849ae83 100644 --- a/arch/frv/include/uapi/asm/socket.h +++ b/arch/frv/include/uapi/asm/socket.h @@ -85,5 +85,8 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h index 59be3d87f86d..bce29166de1b 100644 --- a/arch/ia64/include/uapi/asm/socket.h +++ b/arch/ia64/include/uapi/asm/socket.h @@ -94,4 +94,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_IA64_SOCKET_H */ diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h index 7bc4cb273856..14aa4a6bccf1 100644 --- a/arch/m32r/include/uapi/asm/socket.h +++ b/arch/m32r/include/uapi/asm/socket.h @@ -85,4 +85,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_M32R_SOCKET_H */ diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index dec3c850f36b..5910fe294e93 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -103,4 +103,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h index cab7d6d50051..58b1aa01ab9f 100644 --- a/arch/mn10300/include/uapi/asm/socket.h +++ b/arch/mn10300/include/uapi/asm/socket.h @@ -85,4 +85,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index a5cd40cd8ee1..f9cf1223422c 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -84,4 +84,7 @@ #define SO_ATTACH_BPF 0x402B #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 0x402C +#define SO_ATTACH_REUSEPORT_EBPF 0x402D + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h index c046666038f8..dd54f28ecdec 100644 --- a/arch/powerpc/include/uapi/asm/socket.h +++ b/arch/powerpc/include/uapi/asm/socket.h @@ -92,4 +92,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_POWERPC_SOCKET_H */ diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h index 296942d56e6a..d02e89d14fef 100644 --- a/arch/s390/include/uapi/asm/socket.h +++ b/arch/s390/include/uapi/asm/socket.h @@ -91,4 +91,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index e6a16c40be5f..d270ee91968e 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -81,6 +81,9 @@ #define SO_ATTACH_BPF 0x0034 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 0x0035 +#define SO_ATTACH_REUSEPORT_EBPF 0x0036 + /* Security levels - as per NRL IPv6 - don't actually do anything */ #define SO_SECURITY_AUTHENTICATION 0x5001 #define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002 diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h index 4120af086160..fd3b96d1153f 100644 --- a/arch/xtensa/include/uapi/asm/socket.h +++ b/arch/xtensa/include/uapi/asm/socket.h @@ -96,4 +96,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* _XTENSA_SOCKET_H */ diff --git a/include/linux/filter.h b/include/linux/filter.h index 4165e9ac9e36..294c3cdf07b3 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -447,6 +447,8 @@ void bpf_prog_destroy(struct bpf_prog *fp); int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); int sk_attach_bpf(u32 ufd, struct sock *sk); +int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk); +int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk); int sk_detach_filter(struct sock *sk); int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, unsigned int len); diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h index 67d1eb8fd7af..7dda3d7adba8 100644 --- a/include/net/sock_reuseport.h +++ b/include/net/sock_reuseport.h @@ -1,6 +1,8 @@ #ifndef _SOCK_REUSEPORT_H #define _SOCK_REUSEPORT_H +#include +#include #include #include @@ -9,12 +11,18 @@ struct sock_reuseport { u16 max_socks; /* length of socks */ u16 num_socks; /* elements in socks */ + struct bpf_prog __rcu *prog; /* optional BPF sock selector */ struct sock *socks[0]; /* array of sock pointers */ }; extern int reuseport_alloc(struct sock *sk); extern int reuseport_add_sock(struct sock *sk, const struct sock *sk2); extern void reuseport_detach_sock(struct sock *sk); -extern struct sock *reuseport_select_sock(struct sock *sk, u32 hash); +extern struct sock *reuseport_select_sock(struct sock *sk, + u32 hash, + struct sk_buff *skb, + int hdr_len); +extern struct bpf_prog *reuseport_attach_prog(struct sock *sk, + struct bpf_prog *prog); #endif /* _SOCK_REUSEPORT_H */ diff --git a/include/net/udp.h b/include/net/udp.h index 3b5d7f93bc23..2842541e28e7 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -258,7 +258,7 @@ struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif); struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif, - struct udp_table *tbl); + struct udp_table *tbl, struct sk_buff *skb); struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, @@ -266,7 +266,8 @@ struct sock *udp6_lib_lookup(struct net *net, struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, - int dif, struct udp_table *tbl); + int dif, struct udp_table *tbl, + struct sk_buff *skb); /* * SNMP statistics for UDP and UDP-Lite diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 5c15c2a5c123..fb8a41668382 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -87,4 +87,7 @@ #define SO_ATTACH_BPF 50 #define SO_DETACH_BPF SO_DETACH_FILTER +#define SO_ATTACH_REUSEPORT_CBPF 51 +#define SO_ATTACH_REUSEPORT_EBPF 52 + #endif /* __ASM_GENERIC_SOCKET_H */ diff --git a/net/core/filter.c b/net/core/filter.c index c770196ae8d5..35e6fed28709 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -50,6 +50,7 @@ #include #include #include +#include /** * sk_filter - run a packet through a socket filter @@ -1167,17 +1168,32 @@ static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk) return 0; } -/** - * sk_attach_filter - attach a socket filter - * @fprog: the filter program - * @sk: the socket to use - * - * Attach the user's filter code. We first run some sanity checks on - * it to make sure it does not explode on us later. If an error - * occurs or there is insufficient memory for the filter a negative - * errno code is returned. On success the return is zero. - */ -int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) +static int __reuseport_attach_prog(struct bpf_prog *prog, struct sock *sk) +{ + struct bpf_prog *old_prog; + int err; + + if (bpf_prog_size(prog->len) > sysctl_optmem_max) + return -ENOMEM; + + if (sk_unhashed(sk)) { + err = reuseport_alloc(sk); + if (err) + return err; + } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) { + /* The socket wasn't bound with SO_REUSEPORT */ + return -EINVAL; + } + + old_prog = reuseport_attach_prog(sk, prog); + if (old_prog) + bpf_prog_destroy(old_prog); + + return 0; +} + +static +struct bpf_prog *__get_filter(struct sock_fprog *fprog, struct sock *sk) { unsigned int fsize = bpf_classic_proglen(fprog); unsigned int bpf_fsize = bpf_prog_size(fprog->len); @@ -1185,19 +1201,19 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) int err; if (sock_flag(sk, SOCK_FILTER_LOCKED)) - return -EPERM; + return ERR_PTR(-EPERM); /* Make sure new filter is there and in the right amounts. */ if (fprog->filter == NULL) - return -EINVAL; + return ERR_PTR(-EINVAL); prog = bpf_prog_alloc(bpf_fsize, 0); if (!prog) - return -ENOMEM; + return ERR_PTR(-ENOMEM); if (copy_from_user(prog->insns, fprog->filter, fsize)) { __bpf_prog_free(prog); - return -EFAULT; + return ERR_PTR(-EFAULT); } prog->len = fprog->len; @@ -1205,13 +1221,30 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) err = bpf_prog_store_orig_filter(prog, fprog); if (err) { __bpf_prog_free(prog); - return -ENOMEM; + return ERR_PTR(-ENOMEM); } /* bpf_prepare_filter() already takes care of freeing * memory in case something goes wrong. */ - prog = bpf_prepare_filter(prog, NULL); + return bpf_prepare_filter(prog, NULL); +} + +/** + * sk_attach_filter - attach a socket filter + * @fprog: the filter program + * @sk: the socket to use + * + * Attach the user's filter code. We first run some sanity checks on + * it to make sure it does not explode on us later. If an error + * occurs or there is insufficient memory for the filter a negative + * errno code is returned. On success the return is zero. + */ +int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) +{ + struct bpf_prog *prog = __get_filter(fprog, sk); + int err; + if (IS_ERR(prog)) return PTR_ERR(prog); @@ -1225,23 +1258,50 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) } EXPORT_SYMBOL_GPL(sk_attach_filter); -int sk_attach_bpf(u32 ufd, struct sock *sk) +int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk) { - struct bpf_prog *prog; + struct bpf_prog *prog = __get_filter(fprog, sk); int err; + if (IS_ERR(prog)) + return PTR_ERR(prog); + + err = __reuseport_attach_prog(prog, sk); + if (err < 0) { + __bpf_prog_release(prog); + return err; + } + + return 0; +} + +static struct bpf_prog *__get_bpf(u32 ufd, struct sock *sk) +{ + struct bpf_prog *prog; + if (sock_flag(sk, SOCK_FILTER_LOCKED)) - return -EPERM; + return ERR_PTR(-EPERM); prog = bpf_prog_get(ufd); if (IS_ERR(prog)) - return PTR_ERR(prog); + return prog; if (prog->type != BPF_PROG_TYPE_SOCKET_FILTER) { bpf_prog_put(prog); - return -EINVAL; + return ERR_PTR(-EINVAL); } + return prog; +} + +int sk_attach_bpf(u32 ufd, struct sock *sk) +{ + struct bpf_prog *prog = __get_bpf(ufd, sk); + int err; + + if (IS_ERR(prog)) + return PTR_ERR(prog); + err = __sk_attach_prog(prog, sk); if (err < 0) { bpf_prog_put(prog); @@ -1251,6 +1311,23 @@ int sk_attach_bpf(u32 ufd, struct sock *sk) return 0; } +int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk) +{ + struct bpf_prog *prog = __get_bpf(ufd, sk); + int err; + + if (IS_ERR(prog)) + return PTR_ERR(prog); + + err = __reuseport_attach_prog(prog, sk); + if (err < 0) { + bpf_prog_put(prog); + return err; + } + + return 0; +} + #define BPF_RECOMPUTE_CSUM(flags) ((flags) & 1) #define BPF_LDST_LEN 16U diff --git a/net/core/sock.c b/net/core/sock.c index 565bab7baca9..51270238e269 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -134,6 +134,7 @@ #include #include +#include #include @@ -932,6 +933,32 @@ set_rcvbuf: } break; + case SO_ATTACH_REUSEPORT_CBPF: + ret = -EINVAL; + if (optlen == sizeof(struct sock_fprog)) { + struct sock_fprog fprog; + + ret = -EFAULT; + if (copy_from_user(&fprog, optval, sizeof(fprog))) + break; + + ret = sk_reuseport_attach_filter(&fprog, sk); + } + break; + + case SO_ATTACH_REUSEPORT_EBPF: + ret = -EINVAL; + if (optlen == sizeof(u32)) { + u32 ufd; + + ret = -EFAULT; + if (copy_from_user(&ufd, optval, sizeof(ufd))) + break; + + ret = sk_reuseport_attach_bpf(ufd, sk); + } + break; + case SO_DETACH_FILTER: ret = sk_detach_filter(sk); break; @@ -1443,6 +1470,8 @@ void sk_destruct(struct sock *sk) sk_filter_uncharge(sk, filter); RCU_INIT_POINTER(sk->sk_filter, NULL); } + if (rcu_access_pointer(sk->sk_reuseport_cb)) + reuseport_detach_sock(sk); sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP); diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c index 963c8d5f3027..ae0969c0fc2e 100644 --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -1,10 +1,12 @@ /* * To speed up listener socket lookup, create an array to store all sockets * listening on the same port. This allows a decision to be made after finding - * the first socket. + * the first socket. An optional BPF program can also be configured for + * selecting the socket index from the array of available sockets. */ #include +#include #include #define INIT_SOCKS 128 @@ -22,6 +24,7 @@ static struct sock_reuseport *__reuseport_alloc(u16 max_socks) reuse->max_socks = max_socks; + RCU_INIT_POINTER(reuse->prog, NULL); return reuse; } @@ -67,6 +70,7 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse) more_reuse->max_socks = more_socks_size; more_reuse->num_socks = reuse->num_socks; + more_reuse->prog = reuse->prog; memcpy(more_reuse->socks, reuse->socks, reuse->num_socks * sizeof(struct sock *)); @@ -75,6 +79,10 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse) rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb, more_reuse); + /* Note: we use kfree_rcu here instead of reuseport_free_rcu so + * that reuse and more_reuse can temporarily share a reference + * to prog. + */ kfree_rcu(reuse, rcu); return more_reuse; } @@ -116,6 +124,16 @@ int reuseport_add_sock(struct sock *sk, const struct sock *sk2) } EXPORT_SYMBOL(reuseport_add_sock); +static void reuseport_free_rcu(struct rcu_head *head) +{ + struct sock_reuseport *reuse; + + reuse = container_of(head, struct sock_reuseport, rcu); + if (reuse->prog) + bpf_prog_destroy(reuse->prog); + kfree(reuse); +} + void reuseport_detach_sock(struct sock *sk) { struct sock_reuseport *reuse; @@ -131,7 +149,7 @@ void reuseport_detach_sock(struct sock *sk) reuse->socks[i] = reuse->socks[reuse->num_socks - 1]; reuse->num_socks--; if (reuse->num_socks == 0) - kfree_rcu(reuse, rcu); + call_rcu(&reuse->rcu, reuseport_free_rcu); break; } } @@ -139,15 +157,53 @@ void reuseport_detach_sock(struct sock *sk) } EXPORT_SYMBOL(reuseport_detach_sock); +static struct sock *run_bpf(struct sock_reuseport *reuse, u16 socks, + struct bpf_prog *prog, struct sk_buff *skb, + int hdr_len) +{ + struct sk_buff *nskb = NULL; + u32 index; + + if (skb_shared(skb)) { + nskb = skb_clone(skb, GFP_ATOMIC); + if (!nskb) + return NULL; + skb = nskb; + } + + /* temporarily advance data past protocol header */ + if (!pskb_pull(skb, hdr_len)) { + consume_skb(nskb); + return NULL; + } + index = bpf_prog_run_save_cb(prog, skb); + __skb_push(skb, hdr_len); + + consume_skb(nskb); + + if (index >= socks) + return NULL; + + return reuse->socks[index]; +} + /** * reuseport_select_sock - Select a socket from an SO_REUSEPORT group. * @sk: First socket in the group. - * @hash: Use this hash to select. + * @hash: When no BPF filter is available, use this hash to select. + * @skb: skb to run through BPF filter. + * @hdr_len: BPF filter expects skb data pointer at payload data. If + * the skb does not yet point at the payload, this parameter represents + * how far the pointer needs to advance to reach the payload. * Returns a socket that should receive the packet (or NULL on error). */ -struct sock *reuseport_select_sock(struct sock *sk, u32 hash) +struct sock *reuseport_select_sock(struct sock *sk, + u32 hash, + struct sk_buff *skb, + int hdr_len) { struct sock_reuseport *reuse; + struct bpf_prog *prog; struct sock *sk2 = NULL; u16 socks; @@ -158,12 +214,16 @@ struct sock *reuseport_select_sock(struct sock *sk, u32 hash) if (!reuse) goto out; + prog = rcu_dereference(reuse->prog); socks = READ_ONCE(reuse->num_socks); if (likely(socks)) { /* paired with smp_wmb() in reuseport_add_sock() */ smp_rmb(); - sk2 = reuse->socks[reciprocal_scale(hash, socks)]; + if (prog && skb) + sk2 = run_bpf(reuse, socks, prog, skb, hdr_len); + else + sk2 = reuse->socks[reciprocal_scale(hash, socks)]; } out: @@ -171,3 +231,21 @@ out: return sk2; } EXPORT_SYMBOL(reuseport_select_sock); + +struct bpf_prog * +reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog) +{ + struct sock_reuseport *reuse; + struct bpf_prog *old_prog; + + spin_lock_bh(&reuseport_lock); + reuse = rcu_dereference_protected(sk->sk_reuseport_cb, + lockdep_is_held(&reuseport_lock)); + old_prog = rcu_dereference_protected(reuse->prog, + lockdep_is_held(&reuseport_lock)); + rcu_assign_pointer(reuse->prog, prog); + spin_unlock_bh(&reuseport_lock); + + return old_prog; +} +EXPORT_SYMBOL(reuseport_attach_prog); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 762b01f55707..835378365f25 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -514,7 +514,7 @@ begin: struct sock *sk2; hash = udp_ehashfn(net, daddr, hnum, saddr, sport); - sk2 = reuseport_select_sock(sk, hash); + sk2 = reuseport_select_sock(sk, hash, NULL, 0); if (sk2) { result = sk2; goto found; @@ -553,7 +553,7 @@ found: */ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, - int dif, struct udp_table *udptable) + int dif, struct udp_table *udptable, struct sk_buff *skb) { struct sock *sk, *result; struct hlist_nulls_node *node; @@ -602,7 +602,8 @@ begin: struct sock *sk2; hash = udp_ehashfn(net, daddr, hnum, saddr, sport); - sk2 = reuseport_select_sock(sk, hash); + sk2 = reuseport_select_sock(sk, hash, skb, + sizeof(struct udphdr)); if (sk2) { result = sk2; goto found; @@ -647,14 +648,14 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, iph->daddr, dport, inet_iif(skb), - udptable); + udptable, skb); } struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif) { return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, - &udp_table); + &udp_table, NULL); } EXPORT_SYMBOL_GPL(udp4_lib_lookup); @@ -702,7 +703,8 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) struct net *net = dev_net(skb->dev); sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, - iph->saddr, uh->source, skb->dev->ifindex, udptable); + iph->saddr, uh->source, skb->dev->ifindex, udptable, + NULL); if (!sk) { ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); return; /* No socket for error */ diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c index 6116604bf6e8..df1966f3b6ec 100644 --- a/net/ipv4/udp_diag.c +++ b/net/ipv4/udp_diag.c @@ -44,7 +44,7 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, sk = __udp4_lib_lookup(net, req->id.idiag_src[0], req->id.idiag_sport, req->id.idiag_dst[0], req->id.idiag_dport, - req->id.idiag_if, tbl); + req->id.idiag_if, tbl, NULL); #if IS_ENABLED(CONFIG_IPV6) else if (req->sdiag_family == AF_INET6) sk = __udp6_lib_lookup(net, @@ -52,7 +52,7 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb, req->id.idiag_sport, (struct in6_addr *)req->id.idiag_dst, req->id.idiag_dport, - req->id.idiag_if, tbl); + req->id.idiag_if, tbl, NULL); #endif else goto out_nosk; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 6204b8992de4..56fcb55fda31 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -272,7 +272,7 @@ begin: struct sock *sk2; hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); - sk2 = reuseport_select_sock(sk, hash); + sk2 = reuseport_select_sock(sk, hash, NULL, 0); if (sk2) { result = sk2; goto found; @@ -310,7 +310,8 @@ found: struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, - int dif, struct udp_table *udptable) + int dif, struct udp_table *udptable, + struct sk_buff *skb) { struct sock *sk, *result; struct hlist_nulls_node *node; @@ -358,7 +359,8 @@ begin: struct sock *sk2; hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); - sk2 = reuseport_select_sock(sk, hash); + sk2 = reuseport_select_sock(sk, hash, skb, + sizeof(struct udphdr)); if (sk2) { result = sk2; goto found; @@ -407,13 +409,13 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, return sk; return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport, &iph->daddr, dport, inet6_iif(skb), - udptable); + udptable, skb); } struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, const struct in6_addr *daddr, __be16 dport, int dif) { - return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); + return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL); } EXPORT_SYMBOL_GPL(udp6_lib_lookup); @@ -580,7 +582,7 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, struct net *net = dev_net(skb->dev); sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, - inet6_iif(skb), udptable); + inet6_iif(skb), udptable, skb); if (!sk) { ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); -- cgit v1.2.3