first usable version of kernel and commands

After an year of hard work, this is a first "usable" version of Jehanne.

sys/src/kern/ip/netdevmedium.c

@@ -0,0 +1,153 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+#include "ip.h"
+
+static void	netdevbind(Ipifc *ifc, int argc, char **argv);
+static void	netdevunbind(Ipifc *ifc);
+static void	netdevbwrite(Ipifc *ifc, Block *bp, int version, uint8_t *ip);
+static void	netdevread(void *a);
+
+typedef struct	Netdevrock Netdevrock;
+struct Netdevrock
+{
+	Fs	*f;		/* file system we belong to */
+	Proc	*readp;		/* reading process */
+	Chan	*mchan;		/* Data channel */
+};
+
+Medium netdevmedium =
+{
+.name=		"netdev",
+.hsize=		0,
+.mintu=	0,
+.maxtu=	64000,
+.maclen=	0,
+.bind=		netdevbind,
+.unbind=	netdevunbind,
+.bwrite=	netdevbwrite,
+.unbindonclose=	0,
+};
+
+/*
+ *  called to bind an IP ifc to a generic network device
+ *  called with ifc qlock'd
+ */
+static void
+netdevbind(Ipifc *ifc, int argc, char **argv)
+{
+	Chan *mchan;
+	Netdevrock *er;
+
+	if(argc < 2)
+		error(Ebadarg);
+
+	mchan = namec(argv[2], Aopen, ORDWR, 0);
+
+	er = smalloc(sizeof(*er));
+	er->mchan = mchan;
+	er->f = ifc->conv->p->f;
+
+	ifc->arg = er;
+
+	kproc("netdevread", netdevread, ifc);
+}
+
+/*
+ *  called with ifc wlock'd
+ */
+static void
+netdevunbind(Ipifc *ifc)
+{
+	Netdevrock *er = ifc->arg;
+
+	if(er->readp != nil)
+		postnote(er->readp, 1, "unbind", 0);
+
+	/* wait for readers to die */
+	while(er->readp != nil)
+		tsleep(&up->sleep, return0, 0, 300);
+
+	if(er->mchan != nil)
+		cclose(er->mchan);
+
+	free(er);
+}
+
+/*
+ *  called by ipoput with a single block to write
+ */
+static void
+netdevbwrite(Ipifc *ifc, Block *bp, int _1, uint8_t* _2)
+{
+	Netdevrock *er = ifc->arg;
+
+	if(bp->next)
+		bp = concatblock(bp);
+	if(BLEN(bp) < ifc->mintu)
+		bp = adjustblock(bp, ifc->mintu);
+
+	er->mchan->dev->bwrite(er->mchan, bp, 0);
+	ifc->out++;
+}
+
+/*
+ *  process to read from the device
+ */
+static void
+netdevread(void *a)
+{
+	Ipifc *ifc;
+	Block *bp;
+	Netdevrock *er;
+	char *argv[1];
+
+	ifc = a;
+	er = ifc->arg;
+	er->readp = up;	/* hide identity under a rock for unbind */
+	if(waserror()){
+		er->readp = nil;
+		pexit("hangup", 1);
+	}
+	for(;;){
+		bp = er->mchan->dev->bread(er->mchan, ifc->maxtu, 0);
+		if(bp == nil){
+			/*
+			 * get here if mchan is a pipe and other side hangs up
+			 * clean up this interface & get out
+ZZZ is this a good idea?
+			 */
+			poperror();
+			er->readp = nil;
+			argv[0] = "unbind";
+			if(!waserror())
+				ifc->conv->p->ctl(ifc->conv, argv, 1);
+			pexit("hangup", 1);
+		}
+		if(!canrlock(ifc)){
+			freeb(bp);
+			continue;
+		}
+		if(waserror()){
+			runlock(ifc);
+			nexterror();
+		}
+		ifc->in++;
+		if(ifc->lifc == nil)
+			freeb(bp);
+		else
+			ipiput4(er->f, ifc, bp);
+		runlock(ifc);
+		poperror();
+	}
+}
+
+void
+netdevmediumlink(void)
+{
+	addipmedium(&netdevmedium);
+}