From 16543a0136c00391ecb7e38a13878eb806648bf7 Mon Sep 17 00:00:00 2001 From: Arturo Borrero Gonzalez Date: Mon, 1 Jul 2019 12:53:28 +0200 Subject: libnftables: export public symbols only Export public symbols (the library API functions) instead of all symbols in the library. This patch introduces the required macros to manage the visibility attributes (mostly copied from libnftnl.git) and also marks each symbol as exported when they need to be public. Also, introduce a .map file for proper symbol versioning. Previous to this patch, libnftables public symbols were: % dpkg-gensymbols -q -plibnftables -v0.9.1 -O -esrc/.libs/libnftables.so.1 | wc -l 527 With this patch, libnftables symbols are: % dpkg-gensymbols -q -plibnftables -v0.9.1 -O -esrc/.libs/libnftables.so.1 libnftables.so.1 libnftables #MINVER# nft_ctx_add_include_path@Base 0.9.1 nft_ctx_buffer_error@Base 0.9.1 nft_ctx_buffer_output@Base 0.9.1 nft_ctx_clear_include_paths@Base 0.9.1 nft_ctx_free@Base 0.9.1 nft_ctx_get_dry_run@Base 0.9.1 nft_ctx_get_error_buffer@Base 0.9.1 nft_ctx_get_output_buffer@Base 0.9.1 nft_ctx_new@Base 0.9.1 nft_ctx_output_get_debug@Base 0.9.1 nft_ctx_output_get_flags@Base 0.9.1 nft_ctx_output_set_debug@Base 0.9.1 nft_ctx_output_set_flags@Base 0.9.1 nft_ctx_set_dry_run@Base 0.9.1 nft_ctx_set_error@Base 0.9.1 nft_ctx_set_output@Base 0.9.1 nft_ctx_unbuffer_error@Base 0.9.1 nft_ctx_unbuffer_output@Base 0.9.1 nft_run_cmd_from_buffer@Base 0.9.1 nft_run_cmd_from_filename@Base 0.9.1 Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- configure.ac | 5 +++++ include/utils.h | 8 ++++++++ m4/gcc4_visibility.m4 | 21 +++++++++++++++++++++ src/Makefile.am | 8 +++++--- src/libnftables.c | 20 ++++++++++++++++++++ src/libnftables.map | 25 +++++++++++++++++++++++++ 6 files changed, 84 insertions(+), 3 deletions(-) create mode 100644 m4/gcc4_visibility.m4 create mode 100644 src/libnftables.map diff --git a/configure.ac b/configure.ac index b71268e8..26a9cb71 100644 --- a/configure.ac +++ b/configure.ac @@ -44,6 +44,11 @@ fi AM_PROG_AR AM_PROG_LIBTOOL +LT_INIT +AM_PROG_CC_C_O +AC_EXEEXT +AC_DISABLE_STATIC +CHECK_GCC_FVISIBILITY AS_IF([test "x$enable_man_doc" = "xyes"], [ AC_CHECK_PROG(A2X, [a2x], [a2x], [no]) diff --git a/include/utils.h b/include/utils.h index e791523c..647e8bbe 100644 --- a/include/utils.h +++ b/include/utils.h @@ -11,6 +11,14 @@ #include #include +#include "config.h" +#ifdef HAVE_VISIBILITY_HIDDEN +# define __visible __attribute__((visibility("default"))) +# define EXPORT_SYMBOL(x) typeof(x) (x) __visible; +#else +# define EXPORT_SYMBOL +#endif + #define BITS_PER_BYTE 8 #define pr_debug(fmt, arg...) printf(fmt, ##arg) diff --git a/m4/gcc4_visibility.m4 b/m4/gcc4_visibility.m4 new file mode 100644 index 00000000..214d3f3a --- /dev/null +++ b/m4/gcc4_visibility.m4 @@ -0,0 +1,21 @@ + +# GCC 4.x -fvisibility=hidden + +AC_DEFUN([CHECK_GCC_FVISIBILITY], [ + AC_LANG_PUSH([C]) + saved_CFLAGS="$CFLAGS" + CFLAGS="$saved_CFLAGS -fvisibility=hidden" + AC_CACHE_CHECK([whether compiler accepts -fvisibility=hidden], + [ac_cv_fvisibility_hidden], AC_COMPILE_IFELSE( + [AC_LANG_SOURCE()], + [ac_cv_fvisibility_hidden=yes], + [ac_cv_fvisibility_hidden=no] + )) + if test "$ac_cv_fvisibility_hidden" = "yes"; then + AC_DEFINE([HAVE_VISIBILITY_HIDDEN], [1], + [True if compiler supports -fvisibility=hidden]) + AC_SUBST([GCC_FVISIBILITY_HIDDEN], [-fvisibility=hidden]) + fi + CFLAGS="$saved_CFLAGS" + AC_LANG_POP([C]) +]) diff --git a/src/Makefile.am b/src/Makefile.am index a1c18fe2..9ad7e1f2 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -19,7 +19,7 @@ AM_CFLAGS = -Wall \ -Wdeclaration-after-statement -Wsign-compare -Winit-self \ -Wformat-nonliteral -Wformat-security -Wmissing-format-attribute \ -Wcast-align -Wundef -Wbad-function-cast \ - -Waggregate-return -Wunused -Wwrite-strings + -Waggregate-return -Wunused -Wwrite-strings ${GCC_FVISIBILITY_HIDDEN} AM_YFLAGS = -d @@ -63,7 +63,8 @@ libnftables_la_SOURCES = \ tcpopt.c \ socket.c \ print.c \ - libnftables.c + libnftables.c \ + libnftables.map # yacc and lex generate dirty code noinst_LTLIBRARIES = libparser.la @@ -77,7 +78,8 @@ libparser_la_CFLAGS = ${AM_CFLAGS} \ -Wno-redundant-decls libnftables_la_LIBADD = ${LIBMNL_LIBS} ${LIBNFTNL_LIBS} libparser.la -libnftables_la_LDFLAGS = -version-info ${libnftables_LIBVERSION} +libnftables_la_LDFLAGS = -version-info ${libnftables_LIBVERSION} \ + --version-script=$(srcdir)/libnftables.map if BUILD_MINIGMP noinst_LTLIBRARIES += libminigmp.la diff --git a/src/libnftables.c b/src/libnftables.c index f2cd267d..2f77a770 100644 --- a/src/libnftables.c +++ b/src/libnftables.c @@ -109,6 +109,7 @@ static void nft_exit(void) mark_table_exit(); } +EXPORT_SYMBOL(nft_ctx_add_include_path); int nft_ctx_add_include_path(struct nft_ctx *ctx, const char *path) { char **tmp; @@ -127,6 +128,7 @@ int nft_ctx_add_include_path(struct nft_ctx *ctx, const char *path) return 0; } +EXPORT_SYMBOL(nft_ctx_clear_include_paths); void nft_ctx_clear_include_paths(struct nft_ctx *ctx) { while (ctx->num_include_paths) @@ -141,6 +143,7 @@ static void nft_ctx_netlink_init(struct nft_ctx *ctx) ctx->nf_sock = nft_mnl_socket_open(); } +EXPORT_SYMBOL(nft_ctx_new); struct nft_ctx *nft_ctx_new(uint32_t flags) { struct nft_ctx *ctx; @@ -226,21 +229,25 @@ static int exit_cookie(struct cookie *cookie) return 0; } +EXPORT_SYMBOL(nft_ctx_buffer_output); int nft_ctx_buffer_output(struct nft_ctx *ctx) { return init_cookie(&ctx->output.output_cookie); } +EXPORT_SYMBOL(nft_ctx_unbuffer_output); int nft_ctx_unbuffer_output(struct nft_ctx *ctx) { return exit_cookie(&ctx->output.output_cookie); } +EXPORT_SYMBOL(nft_ctx_buffer_error); int nft_ctx_buffer_error(struct nft_ctx *ctx) { return init_cookie(&ctx->output.error_cookie); } +EXPORT_SYMBOL(nft_ctx_unbuffer_error); int nft_ctx_unbuffer_error(struct nft_ctx *ctx) { return exit_cookie(&ctx->output.error_cookie); @@ -262,16 +269,19 @@ static const char *get_cookie_buffer(struct cookie *cookie) return cookie->buf; } +EXPORT_SYMBOL(nft_ctx_get_output_buffer); const char *nft_ctx_get_output_buffer(struct nft_ctx *ctx) { return get_cookie_buffer(&ctx->output.output_cookie); } +EXPORT_SYMBOL(nft_ctx_get_error_buffer); const char *nft_ctx_get_error_buffer(struct nft_ctx *ctx) { return get_cookie_buffer(&ctx->output.error_cookie); } +EXPORT_SYMBOL(nft_ctx_free); void nft_ctx_free(struct nft_ctx *ctx) { if (ctx->nf_sock) @@ -287,6 +297,7 @@ void nft_ctx_free(struct nft_ctx *ctx) nft_exit(); } +EXPORT_SYMBOL(nft_ctx_set_output); FILE *nft_ctx_set_output(struct nft_ctx *ctx, FILE *fp) { FILE *old = ctx->output.output_fp; @@ -299,6 +310,7 @@ FILE *nft_ctx_set_output(struct nft_ctx *ctx, FILE *fp) return old; } +EXPORT_SYMBOL(nft_ctx_set_error); FILE *nft_ctx_set_error(struct nft_ctx *ctx, FILE *fp) { FILE *old = ctx->output.error_fp; @@ -311,30 +323,36 @@ FILE *nft_ctx_set_error(struct nft_ctx *ctx, FILE *fp) return old; } +EXPORT_SYMBOL(nft_ctx_get_dry_run); bool nft_ctx_get_dry_run(struct nft_ctx *ctx) { return ctx->check; } +EXPORT_SYMBOL(nft_ctx_set_dry_run); void nft_ctx_set_dry_run(struct nft_ctx *ctx, bool dry) { ctx->check = dry; } +EXPORT_SYMBOL(nft_ctx_output_get_flags); unsigned int nft_ctx_output_get_flags(struct nft_ctx *ctx) { return ctx->output.flags; } +EXPORT_SYMBOL(nft_ctx_output_set_flags); void nft_ctx_output_set_flags(struct nft_ctx *ctx, unsigned int flags) { ctx->output.flags = flags; } +EXPORT_SYMBOL(nft_ctx_output_get_debug); unsigned int nft_ctx_output_get_debug(struct nft_ctx *ctx) { return ctx->debug_mask; } +EXPORT_SYMBOL(nft_ctx_output_set_debug); void nft_ctx_output_set_debug(struct nft_ctx *ctx, unsigned int mask) { ctx->debug_mask = mask; @@ -407,6 +425,7 @@ static int nft_evaluate(struct nft_ctx *nft, struct list_head *msgs, return 0; } +EXPORT_SYMBOL(nft_run_cmd_from_buffer); int nft_run_cmd_from_buffer(struct nft_ctx *nft, const char *buf) { int rc = -EINVAL, parser_rc; @@ -458,6 +477,7 @@ err: return rc; } +EXPORT_SYMBOL(nft_run_cmd_from_filename); int nft_run_cmd_from_filename(struct nft_ctx *nft, const char *filename) { struct cmd *cmd, *next; diff --git a/src/libnftables.map b/src/libnftables.map new file mode 100644 index 00000000..955af380 --- /dev/null +++ b/src/libnftables.map @@ -0,0 +1,25 @@ +LIBNFTABLES_1 { +global: + nft_ctx_add_include_path; + nft_ctx_clear_include_pat; + nft_ctx_new; + nft_ctx_buffer_output; + nft_ctx_unbuffer_output; + nft_ctx_buffer_error; + nft_ctx_unbuffer_error; + nft_ctx_get_output_buffer; + nft_ctx_get_error_buffer; + nft_ctx_free; + nft_ctx_set_output; + nft_ctx_set_error; + nft_ctx_get_dry_run; + nft_ctx_set_dry_run; + nft_ctx_output_get_flags; + nft_ctx_output_set_flags; + nft_ctx_output_get_debug; + nft_ctx_output_set_debug; + nft_run_cmd_from_buffer; + nft_run_cmd_from_filename; + +local: *; +}; -- cgit v1.2.3