[PATCH] uapi glibc compat: fix cases where glibc net/if.h is included before linux/if.h
From: Mikko Rapeli <hidden>
Date: 2016-02-07 14:04:21
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, made the net/if.h and linux/if.h incompatibilities visible as build failures for userspace applications like iproute2. This patch fixes the cases where glibc net/if.h is included before linux/if.h by using the linux/libc-compat.h approach. 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 after 'make headers_install' and combining these headers with plain glibc and gcc headers. The test included not just net/if.h but all compiling glibc headers with linux/if.h and it compiles now without errors and warnings. $ cat usr/libc_conflict_test/libc_headers.h #include <aio.h> #include <aliases.h> #include <alloca.h> #include <argp.h> #include <argz.h> #include <ar.h> //these conflict with each other // #include <arpa/ftp.h> // #include <arpa/inet.h> // #include <arpa/nameser_compat.h> // #include <arpa/nameser.h> // #include <arpa/telnet.h> // #include <arpa/tftp.h> #include <assert.h> #include <byteswap.h> #include <complex.h> #include <cpio.h> #include <crypt.h> #include <ctype.h> #include <dirent.h> #include <dlfcn.h> #include <elf.h> #include <endian.h> #include <envz.h> #include <err.h> #include <errno.h> #include <error.h> #include <execinfo.h> #include <fcntl.h> #include <features.h> #include <fenv.h> #include <fmtmsg.h> #include <fnmatch.h> #include <fstab.h> #include <fts.h> #include <ftw.h> #include <_G_config.h> #include <gconv.h> #include <getopt.h> #include <glob.h> #include <gnu-versions.h> #include <grp.h> #include <gshadow.h> #include <iconv.h> #include <ifaddrs.h> #include <inttypes.h> #include <langinfo.h> #include <lastlog.h> #include <libgen.h> #include <libintl.h> #include <libio.h> #include <limits.h> #include <link.h> #include <locale.h> #include <malloc.h> #include <math.h> #include <mcheck.h> #include <memory.h> #include <mntent.h> #include <monetary.h> #include <mqueue.h> #include <netash/ash.h> #include <netatalk/at.h> #include <netax25/ax25.h> #include <netdb.h> #include <neteconet/ec.h> #include <net/ethernet.h> #include <net/if_arp.h> #include <net/if.h> #include <net/if_packet.h> #include <net/if_ppp.h> #include <net/if_shaper.h> #include <net/if_slip.h> #include <netinet/ether.h> #include <netinet/icmp6.h> #include <netinet/if_ether.h> #include <netinet/if_fddi.h> #include <netinet/if_tr.h> #include <netinet/igmp.h> #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/ip6.h> #include <netinet/ip.h> #include <netinet/ip_icmp.h> #include <netinet/tcp.h> #include <netinet/udp.h> #include <netipx/ipx.h> #include <netiucv/iucv.h> #include <netpacket/packet.h> #include <net/ppp-comp.h> #include <net/ppp_defs.h> #include <netrom/netrom.h> #include <netrose/rose.h> #include <net/route.h> #include <nl_types.h> #include <nss.h> #include <obstack.h> #include <paths.h> #include <poll.h> #include <printf.h> #include <protocols/routed.h> #include <protocols/rwhod.h> // conflicts with arap headers //#include <protocols/talkd.h> #include <protocols/timed.h> #include <pthread.h> #include <pty.h> #include <pwd.h> #include <re_comp.h> #include <regex.h> // conflicts with arpa headers //#include <resolv.h> #include <sched.h> #include <scsi/scsi.h> #include <scsi/scsi_ioctl.h> #include <scsi/sg.h> #include <search.h> #include <semaphore.h> #include <setjmp.h> #include <sgtty.h> #include <shadow.h> #include <signal.h> #include <spawn.h> #include <stab.h> #include <stdc-predef.h> #include <stdint.h> #include <stdio_ext.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <stropts.h> #include <syscall.h> #include <sysexits.h> #include <syslog.h> #include <tar.h> #include <termio.h> #include <termios.h> #include <tgmath.h> #include <thread_db.h> #include <time.h> #include <ttyent.h> #include <uchar.h> #include <ucontext.h> #include <ulimit.h> #include <unistd.h> #include <ustat.h> #include <utime.h> #include <utmp.h> #include <utmpx.h> #include <values.h> #include <wait.h> #include <wchar.h> #include <wctype.h> #include <wordexp.h> #include <xlocale.h> $ cat iproute2_bug.h #include <libc_headers.h> #include <linux/if.h> $ cc -Wall -c -nostdinc -I ../include/ -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.ddxtNf -I /home/mcfrisk/src/linux-2.6/usr/headers_compile_test_include.ddxtNf/i586-linux-gnu -o /dev/null ./iproute2_bug.h Reported-by: Stephen Hemminger <redacted> Reported-by: Josh Boyer <jwboyer-rxtnV0ftBwyoClj4AeEUq9i2O/JbrIOy@public.gmane.org> Signed-off-by: Mikko Rapeli <redacted> --- include/uapi/linux/if.h | 21 +++++++++++++++++++++ include/uapi/linux/libc-compat.h | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+)
diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
index 9cf2394..5a07a67 100644
--- a/include/uapi/linux/if.h
+++ b/include/uapi/linux/if.h@@ -19,11 +19,15 @@ #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 */ +/* For compatibility with glibc net/if.h */ +#if __UAPI_DEF_IF_IFNAMSIZ #define IFNAMSIZ 16 +#endif /* __UAPI_DEF_IF_IFNAMSIZ */ #define IFALIASZ 256 #include <linux/hdlc/ioctl.h>
@@ -68,6 +72,8 @@ * @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 +90,14 @@ 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 */ IFF_LOWER_UP = 1<<16, /* volatile */ IFF_DORMANT = 1<<17, /* volatile */ IFF_ECHO = 1<<18, /* volatile */ }; +/* 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
@@ -105,6 +114,8 @@ 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 */ + #define IFF_LOWER_UP IFF_LOWER_UP #define IFF_DORMANT IFF_DORMANT #define IFF_ECHO IFF_ECHO
@@ -166,6 +177,8 @@ 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 +188,7 @@ 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 +214,8 @@ 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 +239,7 @@ 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 +266,8 @@ 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 +275,8 @@ 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..9211e52 100644
--- a/include/uapi/linux/libc-compat.h
+++ b/include/uapi/linux/libc-compat.h@@ -51,6 +51,32 @@ /* 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 +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 0 + +#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 +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1 + +#endif /* _NET_IF_H */ + /* Coordinate with glibc netinet/in.h header. */ #if defined(_NETINET_IN_H)
@@ -117,6 +143,13 @@ * 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 +#define __UAPI_DEF_IF_NET_DEVICE_FLAGS 1 + /* Definitions for in.h */ #define __UAPI_DEF_IN_ADDR 1 #define __UAPI_DEF_IN_IPPROTO 1
--
2.7.0.rc3