reduce the binary size of libpcap based programs that don't use bpf parsing

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@13686 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 119 insertions, 1 deletions

diff --git a/package/libpcap/Makefile b/package/libpcap/Makefile
index cf0304b4cf..620fdb94bc 100644
--- a/package/libpcap/Makefile
+++ b/package/libpcap/Makefile
@@ -30,7 +30,8 @@ define Package/libpcap/description
  packet capture.
 endef
 
-TARGET_CFLAGS += $(FPIC)
+TARGET_CFLAGS += \
+	-ffunction-sections -fdata-sections
 
 CONFIGURE_ARGS += \
 	--enable-shared \
diff --git a/package/libpcap/patches/105-space_optimization.patch b/package/libpcap/patches/105-space_optimization.patch
new file mode 100644
index 0000000000..17265cd665
--- /dev/null
+++ b/package/libpcap/patches/105-space_optimization.patch
@@ -0,0 +1,117 @@
+--- a/gencode.c
++++ b/gencode.c
+@@ -429,20 +429,6 @@ pcap_compile_nopcap(int snaplen_arg, int
+ }
+ 
+ /*
+- * Clean up a "struct bpf_program" by freeing all the memory allocated
+- * in it.
+- */
+-void
+-pcap_freecode(struct bpf_program *program)
+-{
+-	program->bf_len = 0;
+-	if (program->bf_insns != NULL) {
+-		free((char *)program->bf_insns);
+-		program->bf_insns = NULL;
+-	}
+-}
+-
+-/*
+  * Backpatch the blocks in 'list' to 'target'.  The 'sense' field indicates
+  * which of the jt and jf fields has been resolved and which is a pointer
+  * back to another unresolved block (or nil).  At least one of the fields
+--- a/optimize.c
++++ b/optimize.c
+@@ -2263,36 +2263,6 @@ icode_to_fcode(root, lenp)
+ 	return fp;
+ }
+ 
+-/*
+- * Make a copy of a BPF program and put it in the "fcode" member of
+- * a "pcap_t".
+- *
+- * If we fail to allocate memory for the copy, fill in the "errbuf"
+- * member of the "pcap_t" with an error message, and return -1;
+- * otherwise, return 0.
+- */
+-int
+-install_bpf_program(pcap_t *p, struct bpf_program *fp)
+-{
+-	size_t prog_size;
+-
+-	/*
+-	 * Free up any already installed program.
+-	 */
+-	pcap_freecode(&p->fcode);
+-
+-	prog_size = sizeof(*fp->bf_insns) * fp->bf_len;
+-	p->fcode.bf_len = fp->bf_len;
+-	p->fcode.bf_insns = (struct bpf_insn *)malloc(prog_size);
+-	if (p->fcode.bf_insns == NULL) {
+-		snprintf(p->errbuf, sizeof(p->errbuf),
+-			 "malloc: %s", pcap_strerror(errno));
+-		return (-1);
+-	}
+-	memcpy(p->fcode.bf_insns, fp->bf_insns, prog_size);
+-	return (0);
+-}
+-
+ #ifdef BDEBUG
+ static void
+ opt_dump(root)
+--- a/pcap.c
++++ b/pcap.c
+@@ -463,6 +463,52 @@ static const u_char charmap[] = {
+ 	(u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377',
+ };
+ 
++/*
++ * Clean up a "struct bpf_program" by freeing all the memory allocated
++ * in it.
++ */
++void
++pcap_freecode(struct bpf_program *program)
++{
++	program->bf_len = 0;
++	if (program->bf_insns != NULL) {
++		free((char *)program->bf_insns);
++		program->bf_insns = NULL;
++	}
++}
++
++
++/*
++ * Make a copy of a BPF program and put it in the "fcode" member of
++ * a "pcap_t".
++ *
++ * If we fail to allocate memory for the copy, fill in the "errbuf"
++ * member of the "pcap_t" with an error message, and return -1;
++ * otherwise, return 0.
++ */
++int
++install_bpf_program(pcap_t *p, struct bpf_program *fp)
++{
++	size_t prog_size;
++
++	/*
++	 * Free up any already installed program.
++	 */
++	pcap_freecode(&p->fcode);
++
++	prog_size = sizeof(*fp->bf_insns) * fp->bf_len;
++	p->fcode.bf_len = fp->bf_len;
++	p->fcode.bf_insns = (struct bpf_insn *)malloc(prog_size);
++	if (p->fcode.bf_insns == NULL) {
++		snprintf(p->errbuf, sizeof(p->errbuf),
++			 "malloc: %s", pcap_strerror(errno));
++		return (-1);
++	}
++	memcpy(p->fcode.bf_insns, fp->bf_insns, prog_size);
++	return (0);
++}
++
++
+ int
+ pcap_strcasecmp(const char *s1, const char *s2)
+ {