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-rw-r--r--bpf_parser.y6
-rw-r--r--bpfc.84
-rw-r--r--bpfc.c16
3 files changed, 20 insertions, 6 deletions
diff --git a/bpf_parser.y b/bpf_parser.y
index 7331cc5..2c566a1 100644
--- a/bpf_parser.y
+++ b/bpf_parser.y
@@ -28,7 +28,7 @@
#include "cpp.h"
int compile_filter(char *file, int verbose, int bypass, int format,
- bool invoke_cpp);
+ bool invoke_cpp, char **cpp_argv);
static int curr_instr = 0;
@@ -735,7 +735,7 @@ static void pretty_printer(const struct sock_fprog *prog, int format)
}
int compile_filter(char *file, int verbose, int bypass, int format,
- bool invoke_cpp)
+ bool invoke_cpp, char **cpp_argv)
{
int i;
struct sock_fprog res;
@@ -745,7 +745,7 @@ int compile_filter(char *file, int verbose, int bypass, int format,
memset(tmp_file, 0, sizeof(tmp_file));
if (invoke_cpp) {
- ret = cpp_exec(file, tmp_file, sizeof(tmp_file), NULL);
+ ret = cpp_exec(file, tmp_file, sizeof(tmp_file), cpp_argv);
if (ret) {
fprintf(stderr, "Failed to invoke C preprocessor!\n");
goto exit;
diff --git a/bpfc.8 b/bpfc.8
index 8a99e2e..3456e1e 100644
--- a/bpfc.8
+++ b/bpfc.8
@@ -65,6 +65,10 @@ Pass the bpf program through the C preprocessor before reading it in
bpfc. This allows #define and #include directives (e.g. to include
definitions from system headers) to be used in the bpf program.
.PP
+.SS -D <name>=<definition>, --define <name>=<definition>
+Add macro definition for the C preprocessor to use it within bpf file. This
+option is used in combination with the -p,--cpp option.
+.PP
.SS -f <format>, --format <format>
Specify a different output format than the default that is netsniff-ng
compatible. The <format> specifier can be: C, netsniff-ng, xt_bpf, tcpdump.
diff --git a/bpfc.c b/bpfc.c
index d360cf5..a45bc98 100644
--- a/bpfc.c
+++ b/bpfc.c
@@ -17,12 +17,14 @@
#include "die.h"
#include "bpf.h"
#include "config.h"
+#include "str.h"
-static const char *short_options = "vhi:Vdbf:p";
+static const char *short_options = "vhi:Vdbf:pD:";
static const struct option long_options[] = {
{"input", required_argument, NULL, 'i'},
{"format", required_argument, NULL, 'f'},
{"cpp", no_argument, NULL, 'p'},
+ {"define", required_argument, NULL, 'D'},
{"verbose", no_argument, NULL, 'V'},
{"bypass", no_argument, NULL, 'b'},
{"dump", no_argument, NULL, 'd'},
@@ -39,7 +41,7 @@ static const char *copyright = "Please report bugs to <netsniff-ng@googlegroups.
"There is NO WARRANTY, to the extent permitted by law.";
extern int compile_filter(char *file, int verbose, int bypass, int format,
- bool invoke_cpp);
+ bool invoke_cpp, char **cpp_argv);
static void __noreturn help(void)
{
@@ -49,6 +51,7 @@ static void __noreturn help(void)
"Options:\n"
" -i|--input <program/-> Berkeley Packet Filter file/stdin\n"
" -p|--cpp Run bpf program through C preprocessor\n"
+ " -D|--define Add macro/define for C preprocessor\n"
" -f|--format <format> Output format: C|netsniff-ng|xt_bpf|tcpdump\n"
" -b|--bypass Bypass filter validation (e.g. for bug testing)\n"
" -V|--verbose Be more verbose\n"
@@ -81,6 +84,8 @@ int main(int argc, char **argv)
{
int ret, verbose = 0, c, opt_index, bypass = 0, format = 0;
bool invoke_cpp = false;
+ char **cpp_argv = NULL;
+ size_t cpp_argc = 0;
char *file = NULL;
setfsuid(getuid());
@@ -104,6 +109,10 @@ int main(int argc, char **argv)
case 'p':
invoke_cpp = true;
break;
+ case 'D':
+ cpp_argv = argv_insert(cpp_argv, &cpp_argc, "-D");
+ cpp_argv = argv_insert(cpp_argv, &cpp_argc, optarg);
+ break;
case 'f':
if (!strncmp(optarg, "C", 1) ||
!strncmp(optarg, "netsniff-ng", 11))
@@ -146,8 +155,9 @@ int main(int argc, char **argv)
if (!file)
panic("No Berkeley Packet Filter program specified!\n");
- ret = compile_filter(file, verbose, bypass, format, invoke_cpp);
+ ret = compile_filter(file, verbose, bypass, format, invoke_cpp, cpp_argv);
+ argv_free(cpp_argv);
xfree(file);
return ret;
}