Message ID | 1389974985-21160-1-git-send-email-msekleta@redhat.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Michal Sekletar <msekleta@redhat.com> Date: Fri, 17 Jan 2014 17:09:45 +0100 > For user space packet capturing libraries such as libpcap, there's > currently only one way to check which BPF extensions are supported > by the kernel, that is, commit aa1113d9f85d ("net: filter: return > -EINVAL if BPF_S_ANC* operation is not supported"). For querying all > extensions at once this might be rather inconvenient. > > Therefore, this patch introduces a new option which can be used as > an argument for getsockopt(), and allows one to obtain information > about which BPF extensions are supported by the current kernel. > > As David Miller suggests, we do not need to define any bits right > now and status quo can just return 0 in order to state that this > versions supports SKF_AD_PROTOCOL up to SKF_AD_PAY_OFFSET. Later > additions to BPF extensions need to add their bits to the > bpf_tell_extensions() function, as documented in the comment. > > Signed-off-by: Michal Sekletar <msekleta@redhat.com> > Cc: David Miller <davem@davemloft.net> > Reviewed-by: Daniel Borkmann <dborkman@redhat.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index e3a1491..3de1394 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -85,4 +85,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/avr32/include/uapi/asm/socket.h b/arch/avr32/include/uapi/asm/socket.h index cbf902e..6e6cd15 100644 --- a/arch/avr32/include/uapi/asm/socket.h +++ b/arch/avr32/include/uapi/asm/socket.h @@ -78,4 +78,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _UAPI__ASM_AVR32_SOCKET_H */ diff --git a/arch/cris/include/uapi/asm/socket.h b/arch/cris/include/uapi/asm/socket.h index 13829aa..ed94e5e 100644 --- a/arch/cris/include/uapi/asm/socket.h +++ b/arch/cris/include/uapi/asm/socket.h @@ -80,6 +80,8 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h index 5d42997..ca2c6e6 100644 --- a/arch/frv/include/uapi/asm/socket.h +++ b/arch/frv/include/uapi/asm/socket.h @@ -78,5 +78,7 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h index c25302f..a1b49ba 100644 --- a/arch/ia64/include/uapi/asm/socket.h +++ b/arch/ia64/include/uapi/asm/socket.h @@ -87,4 +87,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_IA64_SOCKET_H */ diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h index 5296665..6c9a24b 100644 --- a/arch/m32r/include/uapi/asm/socket.h +++ b/arch/m32r/include/uapi/asm/socket.h @@ -78,4 +78,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_M32R_SOCKET_H */ diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 0df9787..a14baa2 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -96,4 +96,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h index 71dedca..6aa3ce1 100644 --- a/arch/mn10300/include/uapi/asm/socket.h +++ b/arch/mn10300/include/uapi/asm/socket.h @@ -78,4 +78,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index f33113a..a586f61 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -77,4 +77,6 @@ #define SO_MAX_PACING_RATE 0x4048 +#define SO_BPF_EXTENSIONS 0x4029 + #endif /* _UAPI_ASM_SOCKET_H */ diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h index fa69832..a9c3e2e 100644 --- a/arch/powerpc/include/uapi/asm/socket.h +++ b/arch/powerpc/include/uapi/asm/socket.h @@ -85,4 +85,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_POWERPC_SOCKET_H */ diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h index c286c2e..e031332 100644 --- a/arch/s390/include/uapi/asm/socket.h +++ b/arch/s390/include/uapi/asm/socket.h @@ -84,4 +84,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _ASM_SOCKET_H */ diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 0f21e9a..54d9608 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -74,6 +74,8 @@ #define SO_MAX_PACING_RATE 0x0031 +#define SO_BPF_EXTENSIONS 0x0032 + /* 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 7db5c22..39acec0 100644 --- a/arch/xtensa/include/uapi/asm/socket.h +++ b/arch/xtensa/include/uapi/asm/socket.h @@ -89,4 +89,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* _XTENSA_SOCKET_H */ diff --git a/include/linux/filter.h b/include/linux/filter.h index ff4e40c..1a95a2d 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -83,6 +83,17 @@ static inline void bpf_jit_free(struct sk_filter *fp) #define SK_RUN_FILTER(FILTER, SKB) sk_run_filter(SKB, FILTER->insns) #endif +static inline int bpf_tell_extensions(void) +{ + /* When adding new BPF extension it is necessary to enumerate + * it here, so userspace software which wants to know what is + * supported can do so by inspecting return value of this + * function + */ + + return 0; +} + enum { BPF_S_RET_K = 1, BPF_S_RET_A, diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 38f14d0..ea0796b 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -80,4 +80,6 @@ #define SO_MAX_PACING_RATE 47 +#define SO_BPF_EXTENSIONS 48 + #endif /* __ASM_GENERIC_SOCKET_H */ diff --git a/net/core/sock.c b/net/core/sock.c index b3f7ee3..0c127dc 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1167,6 +1167,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname, v.val = sock_flag(sk, SOCK_FILTER_LOCKED); break; + case SO_BPF_EXTENSIONS: + v.val = bpf_tell_extensions(); + break; + case SO_SELECT_ERR_QUEUE: v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE); break;