shithub: riscv

Info  •  Files  •  Log  •  Branches

devip: dynamically allocate memory for /net/ndb, increase maximum to 32K

--- a/sys/src/9/ip/devip.c

+++ b/sys/src/9/ip/devip.c

@@ -57,8 +57,11 @@

 extern	void nullmediumlink(void);

 extern	void pktmediumlink(void);

-	long ndbwrite(Fs *f, char *a, ulong off, int n);

+static void ndbopen(Ndb *ndb, int omode);

+static long ndbwrite(Ndb *ndb, char *a, ulong off, int n);

+static long ndbread(Ndb *ndb, char *a, ulong off, int n);

+

 static int

 ip3gen(Chan *c, int i, Dir *dp)

 {

@@ -149,8 +152,8 @@

 		break;

 	case Qndb:

 		p = "ndb";

-		len = strlen(f->ndb);

-		q.vers = f->ndbvers;

+		len = f->ndb.len;

+		q.vers = f->ndb.vers;

 		break;

 	case Qiproute:

 		p = "iproute";

@@ -165,8 +168,8 @@

 		break;

 	}

 	devdir(c, q, p, len, network, prot, dp);

-	if(i == Qndb && f->ndbmtime > kerndate)

-		dp->mtime = f->ndbmtime;

+	if(i == Qndb && f->ndb.mtime > kerndate)

+		dp->mtime = f->ndb.mtime;

 	return 1;

 }

@@ -355,10 +358,7 @@

 	default:

 		break;

 	case Qndb:

-		if((omode & (OWRITE|OTRUNC)) != 0 && !iseve())

-			error(Eperm);

-		if((omode & (OWRITE|OTRUNC)) == (OWRITE|OTRUNC))

-			f->ndb[0] = 0;

+		ndbopen(&f->ndb, omode);

 		break;

 	case Qlog:

 		netlogopen(f);

@@ -640,7 +640,7 @@

  	case Qbootp:

  		return bootpread(a, offset, n);

  	case Qndb:

-		return readstr(offset, a, n, f->ndb);

+		return ndbread(&f->ndb, a, offset, n);

 	case Qiproute:

 		return routeread(f, a, offset, n);

 	case Qipselftab:

@@ -1167,7 +1167,7 @@

 		netlogctl(f, a, n);

 		return n;

 	case Qndb:

-		return ndbwrite(f, a, offset, n);

+		return ndbwrite(&f->ndb, a, offset, n);

 		break;

 	case Qctl:

 		x = f->p[PROTO(ch->qid)];

@@ -1488,17 +1488,72 @@

 	return nc;

 }

-long

-ndbwrite(Fs *f, char *a, ulong off, int n)

+static void

+ndbopen(Ndb *ndb, int omode)

 {

-	if(off > strlen(f->ndb))

+	int trunc;

+

+	trunc = omode & OTRUNC;

+	omode = openmode(omode);

+

+	if((omode == OWRITE || omode == ORDWR || trunc) && !iseve())

+		error(Eperm);

+

+	if(trunc){

+		qlock(ndb);

+		free(ndb->buf);

+		ndb->buf = nil;

+		ndb->len = 0;

+		ndb->vers++;

+		ndb->mtime = seconds();

+		qunlock(ndb);

+	}

+}

+

+static long

+ndbwrite(Ndb *ndb, char *a, ulong off, int n)

+{

+	qlock(ndb);

+	if(waserror()){

+		qunlock(ndb);

+		nexterror();

+	}

+	if(off > ndb->len || off+n >= 32*1024)

 		error(Eio);

-	if(off+n >= sizeof(f->ndb))

-		error(Eio);

-	memmove(f->ndb+off, a, n);

-	f->ndb[off+n] = 0;

-	f->ndbvers++;

-	f->ndbmtime = seconds();

+	if(n > 0){

+		if(off+n > ndb->len){

+			char *nb = realloc(ndb->buf, off+n);

+			if(nb == nil)

+				error(Enomem);

+			ndb->buf = nb;

+			ndb->len = off+n;

+		}

+		memmove(ndb->buf+off, a, n);

+		ndb->vers++;

+		ndb->mtime = seconds();

+	}

+	qunlock(ndb);

+	poperror();

+	return n;

+}

+

+static long

+ndbread(Ndb *ndb, char *a, ulong off, int n)

+{

+	qlock(ndb);

+	if(waserror()){

+		qunlock(ndb);

+		nexterror();

+	}

+	if(off >= ndb->len)

+		n = 0;

+	else {

+		if(off+n > ndb->len)

+			n = ndb->len - off;

+		memmove(a, ndb->buf+off, n);

+	}

+	qunlock(ndb);

+	poperror();

 	return n;

 }

--- a/sys/src/9/ip/ip.h

+++ b/sys/src/9/ip/ip.h

@@ -15,6 +15,7 @@

 typedef struct	Ipifc	Ipifc;

 typedef struct	Iphash	Iphash;

 typedef struct	Ipht	Ipht;

+typedef struct	Ndb	Ndb;

 typedef struct	Netlog	Netlog;

 typedef struct	Medium	Medium;

 typedef struct	Proto	Proto;

@@ -457,6 +458,14 @@

 int unusedlport(Proto *p);

+struct Ndb

+{

+	QLock;

+	char	*buf;

+	int	len;

+	int	vers;

+	long	mtime;

+};

 /*

  *  one per IP protocol stack

@@ -483,9 +492,7 @@

 	Netlog	*alog;

-	char	ndb[1024];		/* an ndb entry for this interface */

-	int	ndbvers;

-	long	ndbmtime;

+	Ndb	ndb;			/* an ndb entry for this interface */

 };

 struct v6params