diff options
authorPeter Bex <>2013-05-10 22:22:57 +0200
committerPeter Bex <>2016-03-04 21:38:49 +0100
commit5b2ca83bcee868d7e2ff603e3b43d93ac807786d (patch)
parentec91a18f1c8e9585533b9e80944e7557885173f5 (diff)
Expose flush ioctl and add listing/getter/setter of datalink types.
For now, we just work with the underlying integer values. Maybe later we'll translate these to symbols?
1 files changed, 47 insertions, 4 deletions
diff --git a/bpf-interface.scm b/bpf-interface.scm
index 3f9e47a..efcb476 100644
--- a/bpf-interface.scm
+++ b/bpf-interface.scm
@@ -4,11 +4,13 @@
;;; Copyright (c) 2013 by Peter Bex, see file COPYING.BSD
(module bpf-interface
- (bpf-open bpf-close bpf? bpf-buffer-length bpf-interface bpf-interface-set!)
+ (bpf-open bpf-close bpf? bpf-buffer-length bpf-flush!
+ bpf-interface bpf-interface-set!
+ bpf-datalink-type bpf-datalink-type-set! bpf-list-datalink-types)
(import chicken scheme foreign)
-(use posix lolevel)
+(use posix lolevel srfi-1)
(foreign-declare "#include <errno.h>")
(foreign-declare "#include <string.h>")
@@ -55,7 +57,7 @@
(fprintf out "#<bpf on interface: ~S>" (bpf-interface obj))
(display "#<bpf (closed)>" out)))
-(define (bpf-open interface #!optional buffer-length)
+(define (bpf-open interface #!key buffer-length promiscuous)
(let lp ((i -1)
(prev-fn #f)
(prev-error #f))
@@ -83,6 +85,9 @@
(when buffer-length
(bpf-buffer-length-set! bpf buffer-length))
(bpf-interface-set! bpf interface)
+ ;; Rather pointless to expose this as a "setter" procedure(?)
+ (when promiscuous
+ (ioctl fd (foreign-value "BIOCPROMISC" int)))
(define (bpf-close bpf)
@@ -91,6 +96,9 @@
(bpf-fd-set! bpf #f))
+(define (bpf-flush! bpf)
+ (ioctl (bpf-fd bpf) (foreign-value "BIOCFLUSH" int)))
;; Returns the *actual* size that was set, the requested size is too big
;; Remember, this can only be done *before* setting the interface.
;; Oddly enough, the interface can be switched afterwards, so there's
@@ -123,8 +131,43 @@
"C_return(((struct ifreq *)i)->ifr_name);") ifreq)))
(define (bpf-buffer-length bpf)
- (let-location ((length int))
+ (let-location ((length unsigned-int))
(ioctl (bpf-fd bpf) (foreign-value "BIOCGBLEN" int) (location length))
+;; These are a bit problematic: there is a shitload of known types.
+;; Maybe we should automatically convert to a symbol, but that
+;; requires coding all of the types in here. OTOH, that's
+;; more-or-less what C is doing with its #defines.
+(define (bpf-datalink-type bpf)
+ (let-location ((type unsigned-int))
+ (ioctl (bpf-fd bpf) (foreign-value "BIOCGDLT" int) (location type))
+ type))
+(define (bpf-datalink-type-set! bpf type)
+ (let-location ((type unsigned-int type))
+ (ioctl (bpf-fd bpf) (foreign-value "BIOCSDLT" int) (location type))
+ (void)))
+(define (bpf-list-datalink-types bpf)
+ ;; First, get the number of types (required slot length)
+ (let ((in (make-blob (foreign-value "sizeof(struct bpf_dltlist)" int))))
+ ((foreign-lambda* void (((c-pointer "struct bpf_dltlist") p))
+ "p->bfl_list = NULL;") (location in))
+ (ioctl (bpf-fd bpf) (foreign-value "BIOCGDLTLIST" int) (location in))
+ (let* ((length ((foreign-lambda* unsigned-int
+ (((c-pointer "struct bpf_dltlist") p))
+ "C_return(p->bfl_len);") (location in)))
+ ;; Now, get that many types
+ (types (make-blob (* (foreign-value "sizeof(u_int)" int) length))))
+ ((foreign-lambda* void (((c-pointer "struct bpf_dltlist") p)
+ ((c-pointer "u_int") list))
+ "p->bfl_list = list;") (location in) (location types))
+ (ioctl (bpf-fd bpf) (foreign-value "BIOCGDLTLIST" int) (location in))
+ (list-tabulate
+ length
+ (lambda (i)
+ ((foreign-lambda* unsigned-int (((c-pointer "u_int") p) (int i))
+ "C_return(p[i]);") (location types) i))))))