allow filter scripts to be loaded without enabling

By applying this patch, ettercap now can load filter scripts (-F)
without enabling the newly loaded script at once; to achieve this, the
flag ":0" is appended to the filename of the filter script, allowing
multiple scripts to be loaded and enabling them individually by using
the interactive interface.

include/ec_filter.h

@@ -136,7 +136,7 @@ void filter_init_mutex(void);
 /* exported functions */
 
 EC_API_EXTERN void filter_packet(struct packet_object *po);
-EC_API_EXTERN int filter_load_file(char *filename, struct filter_list **list);
+EC_API_EXTERN int filter_load_file(char *filename, struct filter_list **list, uint8_t enabled);
 EC_API_EXTERN void filter_unload(struct filter_list **list);
 EC_API_EXTERN void filter_clear(void);
 EC_API_EXTERN void filter_walk_list( int(*cb)(struct filter_list*, void*), void *arg);

man/ettercap.8.in

@@ -629,6 +629,7 @@ ettercap-compliant binary filter file. Read the etterfilter(8) man page for the
 list of functions you can use inside a filter script.
 Any number of filters can be loaded by specifying the option multiple times;
 packets are passed through each filter in the order specified on the command line.
+You can also load a script without enabling it by appending :0 to the filename.
 .br
 NOTE: these filters are different from those set with \-\-pcapfilter. An ettercap
 filter is a content filter and can modify the payload of a packet before

src/ec_filter.c

@@ -43,7 +43,7 @@ static pthread_mutex_t filters_mutex;
 
 /* protos */
 
-int filter_load_file(char *filename, struct filter_list **list);
+int filter_load_file(char *filename, struct filter_list **list, uint8_t enabled);
 void filter_unload(struct filter_list **list);
 static void reconstruct_strings(struct filter_env *fenv, struct filter_header *fh);
 static int compile_regex(struct filter_env *fenv, struct filter_header *fh);
@@ -986,7 +986,7 @@ static int cmp_geq(u_int32 a, u_int32 b)
 /*
  * load the filter from a file 
  */
-int filter_load_file(char *filename, struct filter_list **list)
+int filter_load_file(char *filename, struct filter_list **list, uint8_t enabled)
 {
    int fd;
    void *file;
@@ -1051,8 +1051,8 @@ int filter_load_file(char *filename, struct filter_list **list)
    /* save the name of the loaded filter */
    (*list)->name = strdup(filename);
 
-   /* enable the filter */
-   (*list)->enabled = 1;
+   /* enable the filter if requested */
+   (*list)->enabled = enabled;
 
    FILTERS_UNLOCK;
 

src/ec_parser.c

@@ -200,6 +200,11 @@ void parse_options(int argc, char **argv)
    optind = 0;
 
    while ((c = getopt_long (argc, argv, "A:a:B:CchDdEe:F:f:GhIi:j:k:L:l:M:m:n:oP:pQqiRr:s:Tt:UuV:vW:w:z", long_options, (int *)0)) != EOF) {
+      /* used for parsing arguments */
+      char *opt_end = optarg;
+      while (opt_end && *opt_end) opt_end++;
+      /* enable a loaded filter script? */
+      uint8_t f_enabled = 0;
 
       switch (c) {
 
@@ -301,7 +306,12 @@ void parse_options(int argc, char **argv)
                   break;
 
          case 'F':
-                  if (filter_load_file(optarg, GBL_FILTERS) != ESUCCESS)
+                  /* is there a :0 or :1 appended to the filename? */
+                  if ( (opt_end-optarg >=2) && *(opt_end-2) == ':' ) {
+                     *(opt_end-2) = '\0';
+                     f_enabled = !( *(opt_end-1) == '0' );
+		  }
+                  if (filter_load_file(optarg, GBL_FILTERS, f_enabled) != ESUCCESS)
                      FATAL_ERROR("Cannot load filter file \"%s\"", optarg);
                   break;
 

src/interfaces/curses/ec_curses_filters.c

@@ -151,7 +151,7 @@ static void load_filter(char *path, char *file)
     * load the filters chain.
     * errors are spawned by the function itself
     */
-   filter_load_file(tmp, GBL_FILTERS);
+   filter_load_file(tmp, GBL_FILTERS, 1);
 
    SAFE_FREE(tmp);
 }

src/interfaces/gtk/ec_gtk_filters.c

@@ -61,7 +61,7 @@ void gtkui_load_filter(void)
        * load the filters chain.
        * errors are spawned by the function itself
        */
-      filter_load_file(filename, GBL_FILTERS);
+      filter_load_file(filename, GBL_FILTERS, 1);
    }
    gtk_widget_destroy (dialog);
 }

utils/etterfilter/ef_test.c

@@ -57,7 +57,7 @@ void test_filter(char *filename)
    /*memset(fenv, 0, sizeof(struct filter_env));*/
 
    /* load the file */
-   if (filter_load_file(filename, &flist) != ESUCCESS) {
+   if (filter_load_file(filename, &flist, 1) != ESUCCESS) {
       exit(-1);
    }
    fenv = &flist->env;