glibc's net/if.h contains copies of definitions from linux/if.h and these conflict and cause build failures if both files are included by application source code. Changes in uapi headers, which fixed header file dependencies to include linux/if.h when it was needed, e.g. commit 1ffad83d, made the net/if.h and linux/if.h incompatibilities visible as build failures for userspace applications like iproute2 and xtables-addons. This patch fixes compile errors when glibc net/if.h is included before linux/if.h: ./linux/if.h:99:21: error: redeclaration of enumerator ‘IFF_NOARP’ ./linux/if.h:98:23: error: redeclaration of enumerator ‘IFF_RUNNING’ ./linux/if.h:97:26: error: redeclaration of enumerator ‘IFF_NOTRAILERS’ ./linux/if.h:96:27: error: redeclaration of enumerator ‘IFF_POINTOPOINT’ ./linux/if.h:95:24: error: redeclaration of enumerator ‘IFF_LOOPBACK’ ./linux/if.h:94:21: error: redeclaration of enumerator ‘IFF_DEBUG’ ./linux/if.h:93:25: error: redeclaration of enumerator ‘IFF_BROADCAST’ ./linux/if.h:92:19: error: redeclaration of enumerator ‘IFF_UP’ ./linux/if.h:252:8: error: redefinition of ‘struct ifconf’ ./linux/if.h:203:8: error: redefinition of ‘struct ifreq’ ./linux/if.h:169:8: error: redefinition of ‘struct ifmap’ ./linux/if.h:107:23: error: redeclaration of enumerator ‘IFF_DYNAMIC’ ./linux/if.h:106:25: error: redeclaration of enumerator ‘IFF_AUTOMEDIA’ ./linux/if.h:105:23: error: redeclaration of enumerator ‘IFF_PORTSEL’ ./linux/if.h:104:25: error: redeclaration of enumerator ‘IFF_MULTICAST’ ./linux/if.h:103:21: error: redeclaration of enumerator ‘IFF_SLAVE’ ./linux/if.h:102:22: error: redeclaration of enumerator ‘IFF_MASTER’ ./linux/if.h:101:24: error: redeclaration of enumerator ‘IFF_ALLMULTI’ ./linux/if.h:100:23: error: redeclaration of enumerator ‘IFF_PROMISC’ The cases where linux/if.h is included before net/if.h need a similar fix in the glibc side, or the order of include files can be changed userspace code as a workaround. This change was tested in x86 userspace on Debian unstable with scripts/headers_compile_test.sh: $ make headers_install && \ cd usr/include && ../../scripts/headers_compile_test.sh -l -k ... cc -Wall -c -nostdinc -I /usr/lib/gcc/i586-linux-gnu/5/include -I /usr/lib/gcc/i586-linux-gnu/5/include-fixed -I . -I /home/mcfrisk/src/linux-2.6/usr/headers_compile_test_include.2uX2zH -I /home/mcfrisk/src/linux-2.6/usr/headers_compile_test_include.2uX2zH/i586-linux-gnu -o /dev/null ./linux/if.h_libc_before_kernel.h PASSED libc before kernel test: ./linux/if.h Reported-by: Jan Engelhardt <jengelh@xxxxxxx> Reported-by: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx> Reported-by: Stephen Hemminger <shemming@xxxxxxxxxxx> Reported-by: Waldemar Brodkorb <mail@xxxxxxxxxxxxxxxxxxxx> Cc: Gabriel Laskar <gabriel@xxxxxxxxxxxx> Signed-off-by: Mikko Rapeli <mikko.rapeli@xxxxxx> --- include/uapi/linux/if.h | 28 +++++++++++++++++++++++++ include/uapi/linux/libc-compat.h | 44 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+) v1: http://marc.info/?l=linux-kernel&m=145485386721798&w=2 v2: Added handling for net_device_flags IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO which are unknown to glibc as suggested by David Miller in http://marc.info/?l=linux-kernel&m=145650410726228&w=2 diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h index f802775..e601c8c 100644 --- a/include/uapi/linux/if.h +++ b/include/uapi/linux/if.h @@ -19,14 +19,20 @@ #ifndef _LINUX_IF_H #define _LINUX_IF_H +#include <linux/libc-compat.h> /* for compatibility with glibc */ #include <linux/types.h> /* for "__kernel_caddr_t" et al */ #include <linux/socket.h> /* for "struct sockaddr" et al */ #include <linux/compiler.h> /* for "__user" et al */ +#if __UAPI_DEF_IF_IFNAMSIZ #define IFNAMSIZ 16 +#endif /* __UAPI_DEF_IF_IFNAMSIZ */ #define IFALIASZ 256 #include <linux/hdlc/ioctl.h> +/* For glibc compatibility. An empty enum does not compile. */ +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO != 0 && \ + __UAPI_DEF_IF_NET_DEVICE_FLAGS != 0 /** * enum net_device_flags - &struct net_device flags * @@ -68,6 +74,8 @@ * @IFF_ECHO: echo sent packets. Volatile. */ enum net_device_flags { +/* for compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS IFF_UP = 1<<0, /* sysfs */ IFF_BROADCAST = 1<<1, /* volatile */ IFF_DEBUG = 1<<2, /* sysfs */ @@ -84,11 +92,17 @@ enum net_device_flags { IFF_PORTSEL = 1<<13, /* sysfs */ IFF_AUTOMEDIA = 1<<14, /* sysfs */ IFF_DYNAMIC = 1<<15, /* sysfs */ +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS */ +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO IFF_LOWER_UP = 1<<16, /* volatile */ IFF_DORMANT = 1<<17, /* volatile */ IFF_ECHO = 1<<18, /* volatile */ +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */ }; +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO != 0 && __UAPI_DEF_IF_NET_DEVICE_FLAGS != 0 */ +/* for compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS #define IFF_UP IFF_UP #define IFF_BROADCAST IFF_BROADCAST #define IFF_DEBUG IFF_DEBUG @@ -105,9 +119,13 @@ enum net_device_flags { #define IFF_PORTSEL IFF_PORTSEL #define IFF_AUTOMEDIA IFF_AUTOMEDIA #define IFF_DYNAMIC IFF_DYNAMIC +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS */ + +#if __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO #define IFF_LOWER_UP IFF_LOWER_UP #define IFF_DORMANT IFF_DORMANT #define IFF_ECHO IFF_ECHO +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */ #define IFF_VOLATILE (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_BROADCAST|IFF_ECHO|\ IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT) @@ -166,6 +184,8 @@ enum { * being very small might be worth keeping for clean configuration. */ +/* for compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_IFMAP struct ifmap { unsigned long mem_start; unsigned long mem_end; @@ -175,6 +195,7 @@ struct ifmap { unsigned char port; /* 3 bytes spare */ }; +#endif /* __UAPI_DEF_IF_IFMAP */ struct if_settings { unsigned int type; /* Type of physical device or protocol */ @@ -200,6 +221,8 @@ struct if_settings { * remainder may be interface specific. */ +/* for compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_IFREQ struct ifreq { #define IFHWADDRLEN 6 union @@ -223,6 +246,7 @@ struct ifreq { struct if_settings ifru_settings; } ifr_ifru; }; +#endif /* __UAPI_DEF_IF_IFREQ */ #define ifr_name ifr_ifrn.ifrn_name /* interface name */ #define ifr_hwaddr ifr_ifru.ifru_hwaddr /* MAC address */ @@ -249,6 +273,8 @@ struct ifreq { * must know all networks accessible). */ +/* for compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_IFCONF struct ifconf { int ifc_len; /* size of buffer */ union { @@ -256,6 +282,8 @@ struct ifconf { struct ifreq __user *ifcu_req; } ifc_ifcu; }; +#endif /* __UAPI_DEF_IF_IFCONF */ + #define ifc_buf ifc_ifcu.ifcu_buf /* buffer address */ #define ifc_req ifc_ifcu.ifcu_req /* array of structures */ diff --git a/include/uapi/linux/libc-compat.h b/include/uapi/linux/libc-compat.h index 7d024ce..d5e38c7 100644 --- a/include/uapi/linux/libc-compat.h +++ b/include/uapi/linux/libc-compat.h @@ -51,6 +51,40 @@ /* We have included glibc headers... */ #if defined(__GLIBC__) +/* Coordinate with glibc net/if.h header. */ +#if defined(_NET_IF_H) + +/* GLIBC headers included first so don't define anything + * that would already be defined. */ + +#define __UAPI_DEF_IF_IFCONF 0 +#define __UAPI_DEF_IF_IFMAP 0 +#define __UAPI_DEF_IF_IFNAMSIZ 0 +#define __UAPI_DEF_IF_IFREQ 0 +/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */ +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 0 +/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */ +#ifndef __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1 +#endif /* __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO */ + +#else /* _NET_IF_H */ + +/* Linux headers included first, and we must define everything + * we need. The expectation is that glibc will check the + * __UAPI_DEF_* defines and adjust appropriately. */ + +#define __UAPI_DEF_IF_IFCONF 1 +#define __UAPI_DEF_IF_IFMAP 1 +#define __UAPI_DEF_IF_IFNAMSIZ 1 +#define __UAPI_DEF_IF_IFREQ 1 +/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */ +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1 +/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */ +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1 + +#endif /* _NET_IF_H */ + /* Coordinate with glibc netinet/in.h header. */ #if defined(_NETINET_IN_H) @@ -117,6 +151,16 @@ * that we need. */ #else /* !defined(__GLIBC__) */ +/* Definitions for if.h */ +#define __UAPI_DEF_IF_IFCONF 1 +#define __UAPI_DEF_IF_IFMAP 1 +#define __UAPI_DEF_IF_IFNAMSIZ 1 +#define __UAPI_DEF_IF_IFREQ 1 +/* Everything up to IFF_DYNAMIC, matches net/if.h until glibc 2.23 */ +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1 +/* For the future if glibc adds IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO */ +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 1 + /* Definitions for in.h */ #define __UAPI_DEF_IN_ADDR 1 #define __UAPI_DEF_IN_IPPROTO 1 -- 2.8.0.rc3 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
