diff options
| -rw-r--r-- | bpf-interface.scm | 51 |
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))) bpf))))) (define (bpf-close bpf) @@ -91,6 +96,9 @@ (bpf-fd-set! bpf #f)) (void)) +(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)) 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)))))) + ) |