struct procprotect_ctx {
struct inode **inode;
+ struct qstr *q;
+ struct path *path;
int flags;
};
struct proc_dir_entry *proc_entry;
+static int run_acl(unsigned long ino) {
+ struct hlist_node *n;
+ struct acl_entry *entry;
+ hlist_for_each_entry_rcu(entry,
+ n, &procprotect_hash[ino & (HASH_SIZE-1)],
+ hlist) {
+ if (entry->ino==ino) {
+ return 0;
+ }
+ }
+ return 1;
+}
+
/*
Entry point of intercepted call. We need to do two things here:
- Decide if we need the heavier return hook to be called
- Save the first argument, which is in a register, for consideration in the return hook
*/
-static int do_lookup_entry(struct kretprobe_instance *ri, struct pt_regs *regs) {
+static int lookup_fast_entry(struct kretprobe_instance *ri, struct pt_regs *regs) {
int ret = -1;
struct procprotect_ctx *ctx;
struct nameidata *nd = (struct nameidata *) regs->di;
return ret;
}
-static int run_acl(unsigned long ino) {
- struct hlist_node *n;
- struct acl_entry *entry;
- hlist_for_each_entry_rcu(entry,
- n, &procprotect_hash[ino & (HASH_SIZE-1)],
- hlist) {
- if (entry->ino==ino) {
- return 0;
+/* The entry hook ensures that the return hook is only called for
+ accesses to /proc */
+
+int printed=0;
+
+static int lookup_fast_ret(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ struct procprotect_ctx *ctx = (struct procprotect_ctx *) ri->data;
+ int ret = regs->ax;
+
+ if (ret==0) {
+ /* The kernel is going to honor the request. Here's where we step in */
+ struct inode *inode = *(ctx->inode);
+ if (!run_acl(inode->i_ino)) {
+ if (current->nsproxy->mnt_ns!=init_task.nsproxy->mnt_ns) {
+ regs->ax = -EPERM;
+ }
}
}
- return 1;
+
+
+ return 0;
+}
+
+static int lookup_slow_entry(struct kretprobe_instance *ri, struct pt_regs *regs) {
+ int ret = -1;
+ struct procprotect_ctx *ctx;
+ struct nameidata *nd = (struct nameidata *) regs->di;
+ struct qstr *q = (struct qstr *) regs->si;
+ struct path *p = (struct path *) regs->dx;
+
+ struct dentry *parent = nd->path.dentry;
+ struct inode *pinode = parent->d_inode;
+
+
+
+ if (pinode->i_sb->s_magic == PROC_SUPER_MAGIC
+ && current->nsproxy->mnt_ns!=init_task.nsproxy->mnt_ns) {
+
+ ctx = (struct procprotect_ctx *) ri->data;
+ ctx->q = q;
+ ctx->flags = nd->flags;
+ ctx->path = p;
+ ret = 0;
+ }
+
+ return ret;
}
/* The entry hook ensures that the return hook is only called for
accesses to /proc */
-static int do_lookup_ret(struct kretprobe_instance *ri, struct pt_regs *regs)
+static int lookup_slow_ret(struct kretprobe_instance *ri, struct pt_regs *regs)
{
struct procprotect_ctx *ctx = (struct procprotect_ctx *) ri->data;
int ret = regs->ax;
if (ret==0) {
/* The kernel is going to honor the request. Here's where we step in */
- struct inode *inode = *(ctx->inode);
+ struct path *p = ctx->path;
+ struct inode *inode = p->dentry->d_inode;
if (!run_acl(inode->i_ino)) {
if (current->nsproxy->mnt_ns!=init_task.nsproxy->mnt_ns) {
regs->ax = -EPERM;
.entry = (kprobe_opcode_t *) do_last_probe
};
-static struct kretprobe proc_probe = {
- .entry_handler = (kprobe_opcode_t *) do_lookup_entry,
- .handler = (kprobe_opcode_t *) do_lookup_ret,
+static struct kretprobe fast_probe = {
+ .entry_handler = (kprobe_opcode_t *) lookup_fast_entry,
+ .handler = (kprobe_opcode_t *) lookup_fast_ret,
+ .maxactive = 20,
+ .data_size = sizeof(struct procprotect_ctx)
+};
+
+static struct kretprobe slow_probe = {
+ .entry_handler = (kprobe_opcode_t *) lookup_slow_entry,
+ .handler = (kprobe_opcode_t *) lookup_slow_ret,
.maxactive = 20,
.data_size = sizeof(struct procprotect_ctx)
};
static void __exit procprotect_exit(void)
{
- unregister_kretprobe(&proc_probe);
+ unregister_kretprobe(&fast_probe);
+ unregister_kretprobe(&slow_probe);
unregister_jprobe(&dolast_probe);
struct hlist_node *n;
struct acl_entry *entry;
}
else
pathname[count]='\0';
+
add_entry(pathname);
printk(KERN_CRIT "Length of buffer=%d",strlen(pathname));
return count;
aclqpath.name = aclpath;
aclqpath.len = strnlen(aclpath, PATH_MAX);
- proc_probe.kp.addr =
- (kprobe_opcode_t *) kallsyms_lookup_name("lookup_fast");
- if (!proc_probe.kp.addr) {
- printk("Couldn't find %s to plant kretprobe\n", "lookup_fast");
- return -1;
- }
-
dolast_probe.kp.addr =
(kprobe_opcode_t *) kallsyms_lookup_name("do_last");
printk("register_jprobe failed, returned %u\n", ret);
return -1;
}
+ fast_probe.kp.addr =
+ (kprobe_opcode_t *) kallsyms_lookup_name("lookup_fast");
+ if (!fast_probe.kp.addr) {
+ printk("Couldn't find %s to plant kretprobe\n", "lookup_fast");
+ return -1;
+ }
+
+ slow_probe.kp.addr =
+ (kprobe_opcode_t *) kallsyms_lookup_name("lookup_slow");
+ if (!slow_probe.kp.addr) {
+ printk("Couldn't find %s to plant kretprobe\n", "lookup_slow");
+ return -1;
+ }
+
+
+
+ if ((ret = register_kretprobe(&fast_probe)) <0) {
+ printk("register_kretprobe failed, returned %d\n", ret);
+ return -1;
+ }
+
+ printk("Planted kretprobe at %p, handler addr %p\n",
+ fast_probe.kp.addr, fast_probe.handler);
- if ((ret = register_kretprobe(&proc_probe)) <0) {
+ if ((ret = register_kretprobe(&slow_probe)) <0) {
printk("register_kretprobe failed, returned %d\n", ret);
return -1;
}
printk("Planted kretprobe at %p, handler addr %p\n",
- proc_probe.kp.addr, proc_probe.handler);
+ slow_probe.kp.addr, slow_probe.handler);
proc_entry = create_proc_entry("procprotect", 0644, NULL);
proc_entry->write_proc = procfile_write;