diff options
Diffstat (limited to 'guix/build/syscalls.scm')
| -rw-r--r-- | guix/build/syscalls.scm | 220 |
1 files changed, 208 insertions, 12 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index 2cee6544c4..9386c0f5d0 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -87,12 +87,16 @@ all-network-interface-names network-interface-names network-interface-flags + network-interface-netmask loopback-network-interface? network-interface-address set-network-interface-flags set-network-interface-address + set-network-interface-netmask set-network-interface-up configure-network-interface + add-network-route/gateway + delete-network-route interface? interface-name @@ -202,7 +206,7 @@ result is the alignment of the \"most strictly aligned component\"." types ...)))) (define-syntax write-type - (syntax-rules (~ array) + (syntax-rules (~ array *) ((_ bv offset (type ~ order) value) (bytevector-uint-set! bv offset value (endianness order) (sizeof* type))) @@ -215,6 +219,9 @@ result is the alignment of the \"most strictly aligned component\"." ((head . tail) (write-type bv o type head) (loop (+ 1 i) tail (+ o (sizeof* type)))))))) + ((_ bv offset '* value) + (bytevector-uint-set! bv offset (pointer-address value) + (native-endianness) (sizeof* '*))) ((_ bv offset type value) (bytevector-uint-set! bv offset value (native-endianness) (sizeof* type))))) @@ -262,6 +269,29 @@ result is the alignment of the \"most strictly aligned component\"." (align offset type0) type0)))))) +(define-syntax define-c-struct-macro + (syntax-rules () + "Define NAME as a macro that can be queried to get information about the C +struct it represents. In particular: + + (NAME field-offset FIELD) + +returns the offset in bytes of FIELD within the C struct represented by NAME." + ((_ name ((fields types) ...)) + (define-c-struct-macro name + (fields ...) 0 () + ((fields types) ...))) + ((_ name (fields ...) offset (clauses ...) ((field type) rest ...)) + (define-c-struct-macro name + (fields ...) + (+ (align offset type) (type-size type)) + (clauses ... ((_ field-offset field) (align offset type))) + (rest ...))) + ((_ name (fields ...) offset (clauses ...) ()) + (define-syntax name + (syntax-rules (field-offset fields ...) + clauses ...))))) + (define-syntax define-c-struct (syntax-rules () "Define SIZE as the size in bytes of the C structure made of FIELDS. READ @@ -269,6 +299,8 @@ as a deserializer and WRITE! as a serializer for the C structure with the given TYPES. READ uses WRAP-FIELDS to return its value." ((_ name size wrap-fields read write! (fields types) ...) (begin + (define-c-struct-macro name + ((fields types) ...)) (define size (struct-size 0 () types ...)) (define (write! bv offset fields ...) @@ -276,6 +308,12 @@ given TYPES. READ uses WRAP-FIELDS to return its value." (define* (read bv #:optional (offset 0)) (read-types wrap-fields bv offset (types ...) ())))))) +(define-syntax-rule (c-struct-field-offset type field) + "Return the offset in BYTES of FIELD within TYPE, where TYPE is a C struct +defined with 'define-c-struct' and FIELD is a field identifier. An +expansion-time error is raised if FIELD does not exist in TYPE." + (type field-offset field)) + ;;; ;;; FFI. @@ -761,6 +799,22 @@ exception if it's already taken." (if (string-contains %host-type "linux") #x8916 ;GNU/Linux -1)) ;FIXME: GNU/Hurd? +(define SIOCGIFNETMASK + (if (string-contains %host-type "linux") + #x891b ;GNU/Linux + -1)) ;FIXME: GNU/Hurd? +(define SIOCSIFNETMASK + (if (string-contains %host-type "linux") + #x891c ;GNU/Linux + -1)) ;FIXME: GNU/Hurd? +(define SIOCADDRT + (if (string-contains %host-type "linux") + #x890B ;GNU/Linux + -1)) ;FIXME: GNU/Hurd? +(define SIOCDELRT + (if (string-contains %host-type "linux") + #x890C ;GNU/Linux + -1)) ;FIXME: GNU/Hurd? ;; Flags and constants from <net/if.h>. @@ -770,10 +824,13 @@ exception if it's already taken." (define IF_NAMESIZE 16) ;maximum interface name size -(define ifconf-struct - ;; 'struct ifconf', from <net/if.h>. - (list int ;int ifc_len - '*)) ;struct ifreq *ifc_ifcu +(define-c-struct %ifconf-struct + sizeof-ifconf + list + read-ifconf + write-ifconf! + (length int) ;int ifc_len + (request '*)) ;struct ifreq *ifc_ifcu (define ifreq-struct-size ;; 'struct ifreq' begins with an array of IF_NAMESIZE bytes containing the @@ -865,15 +922,18 @@ to interfaces that are currently up." (sock (or sock (socket SOCK_STREAM AF_INET 0))) (len (* ifreq-struct-size 10)) (reqs (make-bytevector len)) - (conf (make-c-struct ifconf-struct - (list len (bytevector->pointer reqs))))) + (conf (make-bytevector sizeof-ifconf))) + (write-ifconf! conf 0 + len (bytevector->pointer reqs)) + (let-values (((ret err) - (%ioctl (fileno sock) SIOCGIFCONF conf))) + (%ioctl (fileno sock) SIOCGIFCONF + (bytevector->pointer conf)))) (when close? (close-port sock)) (if (zero? ret) (bytevector->string-list reqs ifreq-struct-size - (match (parse-c-struct conf ifconf-struct) + (match (read-ifconf conf) ((len . _) len))) (throw 'system-error "network-interface-list" "network-interface-list: ~A" @@ -961,6 +1021,22 @@ interface NAME." (list name (strerror err)) (list err)))))) +(define (set-network-interface-netmask socket name sockaddr) + "Set the network mask of interface NAME to SOCKADDR." + (let ((req (make-bytevector ifreq-struct-size))) + (bytevector-copy! (string->utf8 name) 0 req 0 + (min (string-length name) (- IF_NAMESIZE 1))) + ;; Set the 'ifr_addr' field. + (write-socket-address! sockaddr req IF_NAMESIZE) + (let-values (((ret err) + (%ioctl (fileno socket) SIOCSIFNETMASK + (bytevector->pointer req)))) + (unless (zero? ret) + (throw 'system-error "set-network-interface-netmask" + "set-network-interface-netmask on ~A: ~A" + (list name (strerror err)) + (list err)))))) + (define (network-interface-address socket name) "Return the address of network interface NAME. The result is an object of the same type as that returned by 'make-socket-address'." @@ -977,15 +1053,35 @@ the same type as that returned by 'make-socket-address'." (list name (strerror err)) (list err)))))) -(define (configure-network-interface name sockaddr flags) +(define (network-interface-netmask socket name) + "Return the netmask of network interface NAME. The result is an object of +the same type as that returned by 'make-socket-address'." + (let ((req (make-bytevector ifreq-struct-size))) + (bytevector-copy! (string->utf8 name) 0 req 0 + (min (string-length name) (- IF_NAMESIZE 1))) + (let-values (((ret err) + (%ioctl (fileno socket) SIOCGIFNETMASK + (bytevector->pointer req)))) + (if (zero? ret) + (read-socket-address req IF_NAMESIZE) + (throw 'system-error "network-interface-netmask" + "network-interface-netmask on ~A: ~A" + (list name (strerror err)) + (list err)))))) + +(define* (configure-network-interface name sockaddr flags + #:key netmask) "Configure network interface NAME to use SOCKADDR, an address as returned by -'make-socket-address', and FLAGS, a bitwise-or of IFF_* constants." +'make-socket-address', and FLAGS, a bitwise-or of IFF_* constants. If NETMASK +is true, it must be a socket address to use as the network mask." (let ((sock (socket (sockaddr:fam sockaddr) SOCK_STREAM 0))) (dynamic-wind (const #t) (lambda () (set-network-interface-address sock name sockaddr) - (set-network-interface-flags sock name flags)) + (set-network-interface-flags sock name flags) + (when netmask + (set-network-interface-netmask sock name netmask))) (lambda () (close-port sock))))) @@ -1004,6 +1100,106 @@ the same type as that returned by 'make-socket-address'." ;;; +;;; Network routes. +;;; + +(define-c-struct %rtentry ;'struct rtentry' from <net/route.h> + sizeof-rtentry + list + read-rtentry + write-rtentry! + (pad1 unsigned-long) + (destination (array uint8 16)) ;struct sockaddr + (gateway (array uint8 16)) ;struct sockaddr + (genmask (array uint8 16)) ;struct sockaddr + (flags unsigned-short) + (pad2 short) + (pad3 long) + (tos uint8) + (class uint8) + (pad4 (array uint8 (if (= 8 (sizeof* '*)) 3 1))) + (metric short) + (device '*) + (mtu unsigned-long) + (window unsigned-long) + (initial-rtt unsigned-short)) + +(define RTF_UP #x0001) ;'rtentry' flags from <net/route.h> +(define RTF_GATEWAY #x0002) + +(define %sockaddr-any + (make-socket-address AF_INET INADDR_ANY 0)) + +(define add-network-route/gateway + ;; To allow field names to be matched as literals, we need to move them out + ;; of the lambda's body since the parameters have the same name. A lot of + ;; fuss for very little. + (let-syntax ((gateway-offset (identifier-syntax + (c-struct-field-offset %rtentry gateway))) + (destination-offset (identifier-syntax + (c-struct-field-offset %rtentry destination))) + (genmask-offset (identifier-syntax + (c-struct-field-offset %rtentry genmask)))) + (lambda* (socket gateway + #:key (destination %sockaddr-any) (genmask %sockaddr-any)) + "Add a network route for DESTINATION (a socket address as returned by +'make-socket-address') that goes through GATEWAY (a socket address). For +instance, the call: + + (add-network-route/gateway sock + (make-socket-address + AF_INET + (inet-pton AF_INET \"192.168.0.1\") + 0)) + +is equivalent to this 'net-tools' command: + + route add -net default gw 192.168.0.1 + +because the default value of DESTINATION is \"0.0.0.0\"." + (let ((route (make-bytevector sizeof-rtentry 0))) + (write-socket-address! gateway route gateway-offset) + (write-socket-address! destination route destination-offset) + (write-socket-address! genmask route genmask-offset) + (bytevector-u16-native-set! route + (c-struct-field-offset %rtentry flags) + (logior RTF_UP RTF_GATEWAY)) + (let-values (((ret err) + (%ioctl (fileno socket) SIOCADDRT + (bytevector->pointer route)))) + (unless (zero? ret) + (throw 'system-error "add-network-route/gateway" + "add-network-route/gateway: ~A" + (list (strerror err)) + (list err)))))))) + +(define delete-network-route + (let-syntax ((destination-offset (identifier-syntax + (c-struct-field-offset %rtentry destination)))) + (lambda* (socket destination) + "Delete the network route for DESTINATION. For instance, the call: + + (delete-network-route sock + (make-socket-address AF_INET INADDR_ANY 0)) + +is equivalent to the 'net-tools' command: + + route del -net default +" + + (let ((route (make-bytevector sizeof-rtentry 0))) + (write-socket-address! destination route destination-offset) + (let-values (((ret err) + (%ioctl (fileno socket) SIOCDELRT + (bytevector->pointer route)))) + (unless (zero? ret) + (throw 'system-error "delete-network-route" + "delete-network-route: ~A" + (list (strerror err)) + (list err)))))))) + + +;;; ;;; Details about network interfaces---aka. 'getifaddrs'. ;;; |