Module Name: src
Committed By: pooka
Date: Mon Mar 14 15:13:26 UTC 2011
Modified Files:
src/lib/librumphijack: hijack.c
Log Message:
Make fdoffset configurable. Also, enforce that host descriptors
are smaller than the offset.
To generate a diff of this commit:
cvs rdiff -u -r1.84 -r1.85 src/lib/librumphijack/hijack.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/librumphijack/hijack.c
diff -u src/lib/librumphijack/hijack.c:1.84 src/lib/librumphijack/hijack.c:1.85
--- src/lib/librumphijack/hijack.c:1.84 Thu Mar 10 23:02:56 2011
+++ src/lib/librumphijack/hijack.c Mon Mar 14 15:13:26 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: hijack.c,v 1.84 2011/03/10 23:02:56 pooka Exp $ */
+/* $NetBSD: hijack.c,v 1.85 2011/03/14 15:13:26 pooka Exp $ */
/*-
* Copyright (c) 2011 Antti Kantee. All Rights Reserved.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__RCSID("$NetBSD: hijack.c,v 1.84 2011/03/10 23:02:56 pooka Exp $");
+__RCSID("$NetBSD: hijack.c,v 1.85 2011/03/14 15:13:26 pooka Exp $");
#define __ssp_weak_name(fun) _hijack_ ## fun
@@ -274,6 +274,9 @@
static bool fd_isrump(int);
static enum pathtype path_isrump(const char *);
+/* default FD_SETSIZE is 256 ==> default fdoff is 128 */
+static int hijack_fdoff = FD_SETSIZE/2;
+
/*
* Maintain a mapping table for the usual dup2 suspects.
* Could use atomic ops to operate on dup2vec, but an application
@@ -647,6 +650,23 @@
errx(1, "sysctl value should be y(es)/n(o), gave: %s", buf);
}
+static void
+fdoffparser(char *buf)
+{
+ unsigned long fdoff;
+ char *ep;
+
+ if (*buf == '-') {
+ errx(1, "fdoff must not be negative");
+ }
+ fdoff = strtoul(buf, &ep, 10);
+ if (*ep != '\0')
+ errx(1, "invalid fdoff specifier \"%s\"", buf);
+ if (fdoff >= INT_MAX/2 || fdoff < 3)
+ errx(1, "fdoff out of range");
+ hijack_fdoff = fdoff;
+}
+
static struct {
void (*parsefn)(char *);
const char *name;
@@ -657,6 +677,7 @@
{ blanketparser, "blanket", true },
{ vfsparser, "vfs", true },
{ sysctlparser, "sysctl", false },
+ { fdoffparser, "fdoffset", true },
{ NULL, NULL, false },
};
@@ -783,16 +804,13 @@
}
}
-/* Need runtime selection. low for now due to FD_SETSIZE */
-#define HIJACK_FDOFF 128
-
static int
fd_rump2host(int fd)
{
if (fd == -1)
return fd;
- return fd + HIJACK_FDOFF;
+ return fd + hijack_fdoff;
}
static int
@@ -814,7 +832,7 @@
{
if (!isdup2d(fd))
- return fd - HIJACK_FDOFF;
+ return fd - hijack_fdoff;
else
return mapdup2(fd);
}
@@ -823,10 +841,10 @@
fd_isrump(int fd)
{
- return isdup2d(fd) || fd >= HIJACK_FDOFF;
+ return isdup2d(fd) || fd >= hijack_fdoff;
}
-#define assertfd(_fd_) assert(ISDUP2D(_fd_) || (_fd_) >= HIJACK_FDOFF)
+#define assertfd(_fd_) assert(ISDUP2D(_fd_) || (_fd_) >= hijack_fdoff)
static enum pathtype
path_isrump(const char *path)
@@ -885,8 +903,8 @@
if (fd_isrump(oldd)) {
op_fcntl = GETSYSCALL(rump, FCNTL);
oldd = fd_host2rump(oldd);
- if (minfd >= HIJACK_FDOFF)
- minfd -= HIJACK_FDOFF;
+ if (minfd >= hijack_fdoff)
+ minfd -= hijack_fdoff;
isrump = 1;
} else {
op_fcntl = GETSYSCALL(host, FCNTL);
@@ -903,15 +921,22 @@
}
/*
- * dup a host file descriptor so that it doesn't collide with the dup2mask
+ * Check that host fd value does not exceed fdoffset and if necessary
+ * dup the file descriptor so that it doesn't collide with the dup2mask.
*/
static int
-fd_dupgood(int fd)
+fd_host2host(int fd)
{
int (*op_fcntl)(int, int, ...) = GETSYSCALL(host, FCNTL);
int (*op_close)(int) = GETSYSCALL(host, CLOSE);
int ofd, i;
+ if (fd >= hijack_fdoff) {
+ op_close(fd);
+ errno = ENFILE;
+ return -1;
+ }
+
for (i = 1; isdup2d(fd); i++) {
ofd = fd;
fd = op_fcntl(ofd, F_DUPFD, i);
@@ -949,7 +974,7 @@
if (isrump)
fd = fd_rump2host(fd);
else
- fd = fd_dupgood(fd);
+ fd = fd_host2host(fd);
DPRINTF(("open <- %d (%s)\n", fd, whichfd(fd)));
return fd;
@@ -1099,7 +1124,7 @@
if (isrump)
fd = fd_rump2host(fd);
else
- fd = fd_dupgood(fd);
+ fd = fd_host2host(fd);
DPRINTF(("socket <- %d\n", fd));
return fd;
@@ -1125,7 +1150,7 @@
if (fd != -1 && isrump)
fd = fd_rump2host(fd);
else
- fd = fd_dupgood(fd);
+ fd = fd_host2host(fd);
DPRINTF((" <- %d\n", fd));
@@ -1177,7 +1202,7 @@
* So, if fd < HIJACKOFF, we want to do a host closem.
*/
- if (fd < HIJACK_FDOFF) {
+ if (fd < hijack_fdoff) {
int closemfd = fd;
if (rumpclient__closenotify(&closemfd,
@@ -1203,8 +1228,8 @@
}
}
- if (fd >= HIJACK_FDOFF)
- fd -= HIJACK_FDOFF;
+ if (fd >= hijack_fdoff)
+ fd -= hijack_fdoff;
else
fd = 0;
fd = MAX(maxdup2+1, fd);
