From: Alberto Leiva Popper <ydahhrk@gmail.com>
Date: Wed, 28 Dec 2022 22:12:45 +0000 (-0600)
Subject: Compile backtrace out if unavailable on system
X-Git-Tag: 1.5.4~14
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=77d73e6d01c009ae2a342ae4b2c6abf311ae263b;p=thirdparty%2FFORT-validator.git

Compile backtrace out if unavailable on system

backtrace() is a glibc-only feature. Some systems, such as Alpine,
do not support glibc.

It seems one solution is to rely on community ports, but I imagine it'd
be best to offload such a decision to the user. Not the safest.

Instead, if backtrace() is not available, just delete stack traces from
the binary. It's going to be a pain to debug, but that's the world we
live in, I guess.

Turns libexec into an optional dependency. Fixes #87.

Also, the commit contains a review and update of the documentation's
Alpine dependency list. There was a lot of fat in there.
---

diff --git a/configure.ac b/configure.ac
index 3d9e0e8d..c7e7870c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,9 +29,12 @@ AC_SEARCH_LIBS([pthread_create], [pthread], [],
 AC_SEARCH_LIBS([X509_get_version], [crypto], [],
 	[AC_MSG_ERROR([unable to find the X509_get_version() function])]
 )
-AC_SEARCH_LIBS([backtrace],[execinfo],[],
-	[AC_MSG_ERROR([unable to find backtrace() function])]
+
+AC_SEARCH_LIBS([backtrace],[execinfo],
+	[have_backtrace="yes"],
+	[have_backtrace="no"]
 )
+AM_CONDITIONAL([BACKTRACE_ENABLED], [test "x$have_backtrace" != "xno"])
 
 # Dependencies managed by pkg-config
 # By the way: Apparently PKG_CHECK_MODULES is poor practice now. I can't tell;
diff --git a/docs/installation.md b/docs/installation.md
index f3c137cf..9407ec35 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -407,7 +407,7 @@ The following steps are for Alpine Linux 3.12.0
 
 {% highlight bash %}
 su
-apk add build-base autoconf automake pkgconfig openssl openssl-dev jansson jansson-dev bsd-compat-headers rsync libexecinfo libexecinfo-dev libxml2 libxml2-dev libcurl curl-dev
+apk add build-base autoconf automake pkgconfig openssl-dev jansson-dev curl-dev libxml2-dev bsd-compat-headers rsync
 exit
 
 wget https://github.com/NICMx/FORT-validator/releases/download/{{ site.fort-latest-version }}/fort-{{ site.fort-latest-version }}.tar.gz
diff --git a/src/Makefile.am b/src/Makefile.am
index f323d665..ad6c8f78 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -132,6 +132,9 @@ fort_CFLAGS  = -Wall -Wno-cpp -Wpedantic
 # Feel free to temporarily remove this one if you're not using gcc 7.3.0.
 #fort_CFLAGS += $(GCC_WARNS)
 fort_CFLAGS += -std=gnu11 -O2 -g $(FORT_FLAGS) ${XML2_CFLAGS}
+if BACKTRACE_ENABLED
+fort_CFLAGS += -DBACKTRACE_ENABLED
+endif
 fort_LDFLAGS = $(LDFLAGS_DEBUG)
 fort_LDADD   = ${JANSSON_LIBS} ${CURL_LIBS} ${XML2_LIBS}
 
diff --git a/src/log.c b/src/log.c
index 7ed560bd..2d28bb98 100644
--- a/src/log.c
+++ b/src/log.c
@@ -1,6 +1,9 @@
 #include "log.h"
 
+#ifdef BACKTRACE_ENABLED
 #include <execinfo.h>
+#endif
+
 #include <openssl/bio.h>
 #include <openssl/err.h>
 #include <pthread.h>
@@ -66,6 +69,7 @@ static pthread_mutex_t logck;
 void
 print_stack_trace(char const *title)
 {
+#ifdef BACKTRACE_ENABLED
 #define STACK_SIZE 64
 
 	void *array[STACK_SIZE];
@@ -97,6 +101,7 @@ print_stack_trace(char const *title)
 	}
 
 	free(strings);
+#endif /* BACKTRACE_ENABLED */
 }
 
 static void init_config(struct log_config *cfg, bool unit_tests)
@@ -109,6 +114,8 @@ static void init_config(struct log_config *cfg, bool unit_tests)
 	cfg->facility = LOG_DAEMON;
 }
 
+#ifdef BACKTRACE_ENABLED
+
 static void
 sigsegv_handler(int signum)
 {
@@ -135,6 +142,8 @@ sigsegv_handler(int signum)
 	kill(getpid(), signum);
 }
 
+#endif
+
 /*
  * Register better handlers for some signals.
  *
@@ -143,6 +152,7 @@ sigsegv_handler(int signum)
 static void
 register_signal_handlers(void)
 {
+#ifdef BACKTRACE_ENABLED
 	struct sigaction action;
 	void* dummy;
 
@@ -166,6 +176,7 @@ register_signal_handlers(void)
 		pr_op_err("SIGSEGV handler registration failure: %s",
 		    strerror(errno));
 	}
+#endif
 
 	/*
 	 * SIGPIPE can be triggered by any I/O function. libcurl is particularly