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/*
* sysctl.c: General linux system control interface
*
* Begun 24 March 1995, Stephen Tweedie
* Added /proc support, Dec 1995
* Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
* Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
* Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
* Dynamic registration fixes, Stephen Tweedie.
* Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
* Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
* Horn.
* Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
* Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
* Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
* Wendling.
* The list_for_each() macro wasn't appropriate for the sysctl loop.
* Removed it and replaced it with older style, 03/23/00, Bill Wendling
*/
#include <linux/config.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/swapctl.h>
#include <linux/proc_fs.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <asm/uaccess.h>
#ifdef CONFIG_ROOT_NFS
#include <linux/nfs_fs.h>
#endif
#if defined(CONFIG_SYSCTL)
/* External variables not in a header file. */
extern int panic_timeout;
extern int C_A_D;
extern int bdf_prm[], bdflush_min[], bdflush_max[];
extern int sysctl_overcommit_memory;
extern int max_threads;
extern atomic_t nr_queued_signals;
extern int max_queued_signals;
extern int sysrq_enabled;
extern int core_uses_pid;
extern int cad_pid;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
#ifdef CONFIG_KMOD
extern char modprobe_path[];
#endif
#ifdef CONFIG_HOTPLUG
extern char hotplug_path[];
#endif
#ifdef CONFIG_CHR_DEV_SG
extern int sg_big_buff;
#endif
#ifdef CONFIG_SYSVIPC
extern size_t shm_ctlmax;
extern size_t shm_ctlall;
extern int shm_ctlmni;
extern int msg_ctlmax;
extern int msg_ctlmnb;
extern int msg_ctlmni;
extern int sem_ctls[];
#endif
#ifdef __sparc__
extern char reboot_command [];
extern int stop_a_enabled;
#endif
#ifdef CONFIG_ARCH_S390
#ifdef CONFIG_MATHEMU
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
#endif
#ifdef CONFIG_PPC32
extern unsigned long zero_paged_on, powersave_nap;
int proc_dol2crvec(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp);
#endif
#ifdef CONFIG_BSD_PROCESS_ACCT
extern int acct_parm[];
#endif
extern int pgt_cache_water[];
static int parse_table(int *, int, void *, size_t *, void *, size_t,
ctl_table *, void **);
static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp);
static ctl_table root_table[];
static struct ctl_table_header root_table_header =
{ root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
static ctl_table kern_table[];
static ctl_table vm_table[];
#ifdef CONFIG_NET
extern ctl_table net_table[];
#endif
static ctl_table proc_table[];
static ctl_table fs_table[];
static ctl_table debug_table[];
static ctl_table dev_table[];
extern ctl_table random_table[];
/* /proc declarations: */
#ifdef CONFIG_PROC_FS
static ssize_t proc_readsys(struct file *, char *, size_t, loff_t *);
static ssize_t proc_writesys(struct file *, const char *, size_t, loff_t *);
static int proc_sys_permission(struct inode *, int);
struct file_operations proc_sys_file_operations = {
read: proc_readsys,
write: proc_writesys,
};
static struct inode_operations proc_sys_inode_operations = {
permission: proc_sys_permission,
};
extern struct proc_dir_entry *proc_sys_root;
static void register_proc_table(ctl_table *, struct proc_dir_entry *);
static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
#endif
/* The default sysctl tables: */
static ctl_table root_table[] = {
{CTL_KERN, "kernel", NULL, 0, 0555, kern_table},
{CTL_VM, "vm", NULL, 0, 0555, vm_table},
#ifdef CONFIG_NET
{CTL_NET, "net", NULL, 0, 0555, net_table},
#endif
{CTL_PROC, "proc", NULL, 0, 0555, proc_table},
{CTL_FS, "fs", NULL, 0, 0555, fs_table},
{CTL_DEBUG, "debug", NULL, 0, 0555, debug_table},
{CTL_DEV, "dev", NULL, 0, 0555, dev_table},
{0}
};
static ctl_table kern_table[] = {
{KERN_OSTYPE, "ostype", system_utsname.sysname, 64,
0444, NULL, &proc_doutsstring, &sysctl_string},
{KERN_OSRELEASE, "osrelease", system_utsname.release, 64,
0444, NULL, &proc_doutsstring, &sysctl_string},
{KERN_VERSION, "version", system_utsname.version, 64,
0444, NULL, &proc_doutsstring, &sysctl_string},
{KERN_NODENAME, "hostname", system_utsname.nodename, 64,
0644, NULL, &proc_doutsstring, &sysctl_string},
{KERN_DOMAINNAME, "domainname", system_utsname.domainname, 64,
0644, NULL, &proc_doutsstring, &sysctl_string},
{KERN_PANIC, "panic", &panic_timeout, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_CORE_USES_PID, "core_uses_pid", &core_uses_pid, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_TAINTED, "tainted", &tainted, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_CAP_BSET, "cap-bound", &cap_bset, sizeof(kernel_cap_t),
0600, NULL, &proc_dointvec_bset},
#ifdef CONFIG_BLK_DEV_INITRD
{KERN_REALROOTDEV, "real-root-dev", &real_root_dev, sizeof(int),
0644, NULL, &proc_dointvec},
#endif
#ifdef __sparc__
{KERN_SPARC_REBOOT, "reboot-cmd", reboot_command,
256, 0644, NULL, &proc_dostring, &sysctl_string },
{KERN_SPARC_STOP_A, "stop-a", &stop_a_enabled, sizeof (int),
0644, NULL, &proc_dointvec},
#endif
#ifdef CONFIG_PPC32
{KERN_PPC_ZEROPAGED, "zero-paged", &zero_paged_on, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_PPC_POWERSAVE_NAP, "powersave-nap", &powersave_nap, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_PPC_L2CR, "l2cr", NULL, 0,
0644, NULL, &proc_dol2crvec},
#endif
{KERN_CTLALTDEL, "ctrl-alt-del", &C_A_D, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_PRINTK, "printk", &console_loglevel, 4*sizeof(int),
0644, NULL, &proc_dointvec},
#ifdef CONFIG_KMOD
{KERN_MODPROBE, "modprobe", &modprobe_path, 256,
0644, NULL, &proc_dostring, &sysctl_string },
#endif
#ifdef CONFIG_HOTPLUG
{KERN_HOTPLUG, "hotplug", &hotplug_path, 256,
0644, NULL, &proc_dostring, &sysctl_string },
#endif
#ifdef CONFIG_CHR_DEV_SG
{KERN_SG_BIG_BUFF, "sg-big-buff", &sg_big_buff, sizeof (int),
0444, NULL, &proc_dointvec},
#endif
#ifdef CONFIG_BSD_PROCESS_ACCT
{KERN_ACCT, "acct", &acct_parm, 3*sizeof(int),
0644, NULL, &proc_dointvec},
#endif
{KERN_RTSIGNR, "rtsig-nr", &nr_queued_signals, sizeof(int),
0444, NULL, &proc_dointvec},
{KERN_RTSIGMAX, "rtsig-max", &max_queued_signals, sizeof(int),
0644, NULL, &proc_dointvec},
#ifdef CONFIG_SYSVIPC
{KERN_SHMMAX, "shmmax", &shm_ctlmax, sizeof (size_t),
0644, NULL, &proc_doulongvec_minmax},
{KERN_SHMALL, "shmall", &shm_ctlall, sizeof (size_t),
0644, NULL, &proc_doulongvec_minmax},
{KERN_SHMMNI, "shmmni", &shm_ctlmni, sizeof (int),
0644, NULL, &proc_dointvec},
{KERN_MSGMAX, "msgmax", &msg_ctlmax, sizeof (int),
0644, NULL, &proc_dointvec},
{KERN_MSGMNI, "msgmni", &msg_ctlmni, sizeof (int),
0644, NULL, &proc_dointvec},
{KERN_MSGMNB, "msgmnb", &msg_ctlmnb, sizeof (int),
0644, NULL, &proc_dointvec},
{KERN_SEM, "sem", &sem_ctls, 4*sizeof (int),
0644, NULL, &proc_dointvec},
#endif
#ifdef CONFIG_MAGIC_SYSRQ
{KERN_SYSRQ, "sysrq", &sysrq_enabled, sizeof (int),
0644, NULL, &proc_dointvec},
#endif
{KERN_CADPID, "cad_pid", &cad_pid, sizeof (int),
0600, NULL, &proc_dointvec},
{KERN_MAX_THREADS, "threads-max", &max_threads, sizeof(int),
0644, NULL, &proc_dointvec},
{KERN_RANDOM, "random", NULL, 0, 0555, random_table},
{KERN_OVERFLOWUID, "overflowuid", &overflowuid, sizeof(int), 0644, NULL,
&proc_dointvec_minmax, &sysctl_intvec, NULL,
&minolduid, &maxolduid},
{KERN_OVERFLOWGID, "overflowgid", &overflowgid, sizeof(int), 0644, NULL,
&proc_dointvec_minmax, &sysctl_intvec, NULL,
&minolduid, &maxolduid},
#ifdef CONFIG_ARCH_S390
#ifdef CONFIG_MATHEMU
{KERN_IEEE_EMULATION_WARNINGS,"ieee_emulation_warnings",
&sysctl_ieee_emulation_warnings,sizeof(int),0644,NULL,&proc_dointvec},
#endif
{KERN_S390_USER_DEBUG_LOGGING,"userprocess_debug",
&sysctl_userprocess_debug,sizeof(int),0644,NULL,&proc_dointvec},
#endif
{0}
};
static ctl_table vm_table[] = {
{VM_BDFLUSH, "bdflush", &bdf_prm, 9*sizeof(int), 0644, NULL,
&proc_dointvec_minmax, &sysctl_intvec, NULL,
&bdflush_min, &bdflush_max},
{VM_OVERCOMMIT_MEMORY, "overcommit_memory", &sysctl_overcommit_memory,
sizeof(sysctl_overcommit_memory), 0644, NULL, &proc_dointvec},
{VM_PAGERDAEMON, "kswapd",
&pager_daemon, sizeof(pager_daemon_t), 0644, NULL, &proc_dointvec},
{VM_PGT_CACHE, "pagetable_cache",
&pgt_cache_water, 2*sizeof(int), 0644, NULL, &proc_dointvec},
{VM_PAGE_CLUSTER, "page-cluster",
&page_cluster, sizeof(int), 0644, NULL, &proc_dointvec},
{VM_MIN_READAHEAD, "min-readahead",
&vm_min_readahead,sizeof(int), 0644, NULL, &proc_dointvec},
{VM_MAX_READAHEAD, "max-readahead",
&vm_max_readahead,sizeof(int), 0644, NULL, &proc_dointvec},
{0}
};
static ctl_table proc_table[] = {
{0}
};
static ctl_table fs_table[] = {
{FS_NRINODE, "inode-nr", &inodes_stat, 2*sizeof(int),
0444, NULL, &proc_dointvec},
{FS_STATINODE, "inode-state", &inodes_stat, 7*sizeof(int),
0444, NULL, &proc_dointvec},
{FS_NRFILE, "file-nr", &files_stat, 3*sizeof(int),
0444, NULL, &proc_dointvec},
{FS_MAXFILE, "file-max", &files_stat.max_files, sizeof(int),
0644, NULL, &proc_dointvec},
{FS_NRDQUOT, "dquot-nr", &nr_dquots, 2*sizeof(int),
0444, NULL, &proc_dointvec},
{FS_DENTRY, "dentry-state", &dentry_stat, 6*sizeof(int),
0444, NULL, &proc_dointvec},
{FS_OVERFLOWUID, "overflowuid", &fs_overflowuid, sizeof(int), 0644, NULL,
&proc_dointvec_minmax, &sysctl_intvec, NULL,
&minolduid, &maxolduid},
{FS_OVERFLOWGID, "overflowgid", &fs_overflowgid, sizeof(int), 0644, NULL,
&proc_dointvec_minmax, &sysctl_intvec, NULL,
&minolduid, &maxolduid},
{FS_LEASES, "leases-enable", &leases_enable, sizeof(int),
0644, NULL, &proc_dointvec},
{FS_DIR_NOTIFY, "dir-notify-enable", &dir_notify_enable,
sizeof(int), 0644, NULL, &proc_dointvec},
{FS_LEASE_TIME, "lease-break-time", &lease_break_time, sizeof(int),
0644, NULL, &proc_dointvec},
{0}
};
static ctl_table debug_table[] = {
{0}
};
static ctl_table dev_table[] = {
{0}
};
extern void init_irq_proc (void);
void __init sysctl_init(void)
{
#ifdef CONFIG_PROC_FS
register_proc_table(root_table, proc_sys_root);
init_irq_proc();
#endif
}
int do_sysctl(int *name, int nlen, void *oldval, size_t *oldlenp,
void *newval, size_t newlen)
{
struct list_head *tmp;
if (nlen <= 0 || nlen >= CTL_MAXNAME)
return -ENOTDIR;
if (oldval) {
int old_len;
if (!oldlenp || get_user(old_len, oldlenp))
return -EFAULT;
/* XXX: insufficient for SMP, but should be redundant anyway */
if ((ssize_t)old_len < 0)
return -EINVAL;
}
tmp = &root_table_header.ctl_entry;
do {
struct ctl_table_header *head =
list_entry(tmp, struct ctl_table_header, ctl_entry);
void *context = NULL;
int error = parse_table(name, nlen, oldval, oldlenp,
newval, newlen, head->ctl_table,
&context);
if (context)
kfree(context);
if (error != -ENOTDIR)
return error;
tmp = tmp->next;
} while (tmp != &root_table_header.ctl_entry);
return -ENOTDIR;
}
extern asmlinkage long sys_sysctl(struct __sysctl_args *args)
{
struct __sysctl_args tmp;
int error;
if (copy_from_user(&tmp, args, sizeof(tmp)))
return -EFAULT;
lock_kernel();
error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
tmp.newval, tmp.newlen);
unlock_kernel();
return error;
}
/*
* ctl_perm does NOT grant the superuser all rights automatically, because
* some sysctl variables are readonly even to root.
*/
static int test_perm(int mode, int op)
{
if (!current->euid)
mode >>= 6;
else if (in_egroup_p(0))
mode >>= 3;
if ((mode & op & 0007) == op)
return 0;
return -EACCES;
}
static inline int ctl_perm(ctl_table *table, int op)
{
return test_perm(table->mode, op);
}
static int parse_table(int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen,
ctl_table *table, void **context)
{
int n;
repeat:
if (!nlen)
return -ENOTDIR;
if (get_user(n, name))
return -EFAULT;
for ( ; table->ctl_name; table++) {
if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
int error;
if (table->child) {
if (ctl_perm(table, 001))
return -EPERM;
if (table->strategy) {
error = table->strategy(
table, name, nlen,
oldval, oldlenp,
newval, newlen, context);
if (error)
return error;
}
name++;
nlen--;
table = table->child;
goto repeat;
}
error = do_sysctl_strategy(table, name, nlen,
oldval, oldlenp,
newval, newlen, context);
return error;
}
}
return -ENOTDIR;
}
/* Perform the actual read/write of a sysctl table entry. */
int do_sysctl_strategy (ctl_table *table,
int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
int op = 0, rc;
size_t len;
if (oldval)
op |= 004;
if (newval)
op |= 002;
if (ctl_perm(table, op))
return -EPERM;
if (table->strategy) {
rc = table->strategy(table, name, nlen, oldval, oldlenp,
newval, newlen, context);
if (rc < 0)
return rc;
if (rc > 0)
return 0;
}
/* If there is no strategy routine, or if the strategy returns
* zero, proceed with automatic r/w */
if (table->data && table->maxlen) {
if (oldval && oldlenp) {
if (get_user(len, oldlenp))
return -EFAULT;
if (len) {
if (len > table->maxlen)
len = table->maxlen;
if(copy_to_user(oldval, table->data, len))
return -EFAULT;
if(put_user(len, oldlenp))
return -EFAULT;
}
}
if (newval && newlen) {
len = newlen;
if (len > table->maxlen)
len = table->maxlen;
if(copy_from_user(table->data, newval, len))
return -EFAULT;
}
}
return 0;
}
/**
* register_sysctl_table - register a sysctl heirarchy
* @table: the top-level table structure
* @insert_at_head: whether the entry should be inserted in front or at the end
*
* Register a sysctl table heirarchy. @table should be a filled in ctl_table
* array. An entry with a ctl_name of 0 terminates the table.
*
* The members of the &ctl_table structure are used as follows:
*
* ctl_name - This is the numeric sysctl value used by sysctl(2). The number
* must be unique within that level of sysctl
*
* procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
* enter a sysctl file
*
* data - a pointer to data for use by proc_handler
*
* maxlen - the maximum size in bytes of the data
*
* mode - the file permissions for the /proc/sys file, and for sysctl(2)
*
* child - a pointer to the child sysctl table if this entry is a directory, or
* %NULL.
*
* proc_handler - the text handler routine (described below)
*
* strategy - the strategy routine (described below)
*
* de - for internal use by the sysctl routines
*
* extra1, extra2 - extra pointers usable by the proc handler routines
*
* Leaf nodes in the sysctl tree will be represented by a single file
* under /proc; non-leaf nodes will be represented by directories.
*
* sysctl(2) can automatically manage read and write requests through
* the sysctl table. The data and maxlen fields of the ctl_table
* struct enable minimal validation of the values being written to be
* performed, and the mode field allows minimal authentication.
*
* More sophisticated management can be enabled by the provision of a
* strategy routine with the table entry. This will be called before
* any automatic read or write of the data is performed.
*
* The strategy routine may return
*
* < 0 - Error occurred (error is passed to user process)
*
* 0 - OK - proceed with automatic read or write.
*
* > 0 - OK - read or write has been done by the strategy routine, so
* return immediately.
*
* There must be a proc_handler routine for any terminal nodes
* mirrored under /proc/sys (non-terminals are handled by a built-in
* directory handler). Several default handlers are available to
* cover common cases -
*
* proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
* proc_dointvec_minmax(), proc_doulongvec_ms_jiffies_minmax(),
* proc_doulongvec_minmax()
*
* It is the handler's job to read the input buffer from user memory
* and process it. The handler should return 0 on success.
*
* This routine returns %NULL on a failure to register, and a pointer
* to the table header on success.
*/
struct ctl_table_header *register_sysctl_table(ctl_table * table,
int insert_at_head)
{
struct ctl_table_header *tmp;
tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
if (!tmp)
return NULL;
tmp->ctl_table = table;
INIT_LIST_HEAD(&tmp->ctl_entry);
if (insert_at_head)
list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
else
list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
#ifdef CONFIG_PROC_FS
register_proc_table(table, proc_sys_root);
#endif
return tmp;
}
/**
* unregister_sysctl_table - unregister a sysctl table heirarchy
* @header: the header returned from register_sysctl_table
*
* Unregisters the sysctl table and all children. proc entries may not
* actually be removed until they are no longer used by anyone.
*/
void unregister_sysctl_table(struct ctl_table_header * header)
{
list_del(&header->ctl_entry);
#ifdef CONFIG_PROC_FS
unregister_proc_table(header->ctl_table, proc_sys_root);
#endif
kfree(header);
}
/*
* /proc/sys support
*/
#ifdef CONFIG_PROC_FS
/* Scan the sysctl entries in table and add them all into /proc */
static void register_proc_table(ctl_table * table, struct proc_dir_entry *root)
{
struct proc_dir_entry *de;
int len;
mode_t mode;
for (; table->ctl_name; table++) {
/* Can't do anything without a proc name. */
if (!table->procname)
continue;
/* Maybe we can't do anything with it... */
if (!table->proc_handler && !table->child) {
printk(KERN_WARNING "SYSCTL: Can't register %s\n",
table->procname);
continue;
}
len = strlen(table->procname);
mode = table->mode;
de = NULL;
if (table->proc_handler)
mode |= S_IFREG;
else {
mode |= S_IFDIR;
for (de = root->subdir; de; de = de->next) {
if (proc_match(len, table->procname, de))
break;
}
/* If the subdir exists already, de is non-NULL */
}
if (!de) {
de = create_proc_entry(table->procname, mode, root);
if (!de)
continue;
de->data = (void *) table;
if (table->proc_handler) {
de->proc_fops = &proc_sys_file_operations;
de->proc_iops = &proc_sys_inode_operations;
}
}
table->de = de;
if (de->mode & S_IFDIR)
register_proc_table(table->child, de);
}
}
/*
* Unregister a /proc sysctl table and any subdirectories.
*/
static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
{
struct proc_dir_entry *de;
for (; table->ctl_name; table++) {
if (!(de = table->de))
continue;
if (de->mode & S_IFDIR) {
if (!table->child) {
printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
continue;
}
unregister_proc_table(table->child, de);
/* Don't unregister directories which still have entries.. */
if (de->subdir)
continue;
}
/* Don't unregister proc entries that are still being used.. */
if (atomic_read(&de->count))
continue;
table->de = NULL;
remove_proc_entry(table->procname, root);
}
}
static ssize_t do_rw_proc(int write, struct file * file, char * buf,
size_t count, loff_t *ppos)
{
int op;
struct proc_dir_entry *de;
struct ctl_table *table;
size_t res;
ssize_t error;
de = (struct proc_dir_entry*) file->f_dentry->d_inode->u.generic_ip;
if (!de || !de->data)
return -ENOTDIR;
table = (struct ctl_table *) de->data;
if (!table || !table->proc_handler)
return -ENOTDIR;
op = (write ? 002 : 004);
if (ctl_perm(table, op))
return -EPERM;
res = count;
/*
* FIXME: we need to pass on ppos to the handler.
*/
error = (*table->proc_handler) (table, write, file, buf, &res);
if (error)
return error;
return res;
}
static ssize_t proc_readsys(struct file * file, char * buf,
size_t count, loff_t *ppos)
{
return do_rw_proc(0, file, buf, count, ppos);
}
static ssize_t proc_writesys(struct file * file, const char * buf,
size_t count, loff_t *ppos)
{
return do_rw_proc(1, file, (char *) buf, count, ppos);
}
static int proc_sys_permission(struct inode *inode, int op)
{
return test_perm(inode->i_mode, op);
}
/**
* proc_dostring - read a string sysctl
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes a string from/to the user buffer. If the kernel
* buffer provided is not large enough to hold the string, the
* string is truncated. The copied string is %NULL-terminated.
* If the string is being read by the user process, it is copied
* and a newline '\n' is added. It is truncated if the buffer is
* not large enough.
*
* Returns 0 on success.
*/
int proc_dostring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
size_t len;
char *p, c;
if (!table->data || !table->maxlen || !*lenp ||
(filp->f_pos && !write)) {
*lenp = 0;
return 0;
}
if (write) {
len = 0;
p = buffer;
while (len < *lenp) {
if (get_user(c, p++))
return -EFAULT;
if (c == 0 || c == '\n')
break;
len++;
}
if (len >= table->maxlen)
len = table->maxlen-1;
if(copy_from_user(table->data, buffer, len))
return -EFAULT;
((char *) table->data)[len] = 0;
filp->f_pos += *lenp;
} else {
len = strlen(table->data);
if (len > table->maxlen)
len = table->maxlen;
if (len > *lenp)
len = *lenp;
if (len)
if(copy_to_user(buffer, table->data, len))
return -EFAULT;
if (len < *lenp) {
if(put_user('\n', ((char *) buffer) + len))
return -EFAULT;
len++;
}
*lenp = len;
filp->f_pos += len;
}
return 0;
}
/*
* Special case of dostring for the UTS structure. This has locks
* to observe. Should this be in kernel/sys.c ????
*/
static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
int r;
if (!write) {
down_read(&uts_sem);
r=proc_dostring(table,0,filp,buffer,lenp);
up_read(&uts_sem);
} else {
down_write(&uts_sem);
r=proc_dostring(table,1,filp,buffer,lenp);
up_write(&uts_sem);
}
return r;
}
#define OP_SET 0
#define OP_AND 1
#define OP_OR 2
#define OP_MAX 3
#define OP_MIN 4
static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp, int conv, int op)
{
int *i, vleft, first=1, neg, val;
size_t left, len;
#define TMPBUFLEN 20
char buf[TMPBUFLEN], *p;
if (!table->data || !table->maxlen || !*lenp ||
(filp->f_pos && !write)) {
*lenp = 0;
return 0;
}
i = (int *) table->data;
vleft = table->maxlen / sizeof(int);
left = *lenp;
for (; left && vleft--; i++, first=0) {
if (write) {
while (left) {
char c;
if (get_user(c, (char *) buffer))
return -EFAULT;
if (!isspace(c))
break;
left--;
((char *) buffer)++;
}
if (!left)
break;
neg = 0;
len = left;
if (len > TMPBUFLEN-1)
len = TMPBUFLEN-1;
if(copy_from_user(buf, buffer, len))
return -EFAULT;
buf[len] = 0;
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
left--, p++;
}
if (*p < '0' || *p > '9')
break;
val = simple_strtoul(p, &p, 0) * conv;
len = p-buf;
if ((len < left) && *p && !isspace(*p))
break;
if (neg)
val = -val;
buffer += len;
left -= len;
switch(op) {
case OP_SET: *i = val; break;
case OP_AND: *i &= val; break;
case OP_OR: *i |= val; break;
case OP_MAX: if(*i < val)
*i = val;
break;
case OP_MIN: if(*i > val)
*i = val;
break;
}
} else {
p = buf;
if (!first)
*p++ = '\t';
sprintf(p, "%d", (*i) / conv);
len = strlen(buf);
if (len > left)
len = left;
if(copy_to_user(buffer, buf, len))
return -EFAULT;
left -= len;
buffer += len;
}
}
if (!write && !first && left) {
if(put_user('\n', (char *) buffer))
return -EFAULT;
left--, buffer++;
}
if (write) {
p = (char *) buffer;
while (left) {
char c;
if (get_user(c, p++))
return -EFAULT;
if (!isspace(c))
break;
left--;
}
}
if (write && first)
return -EINVAL;
*lenp -= left;
filp->f_pos += *lenp;
return 0;
}
/**
* proc_dointvec - read a vector of integers
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes up to table->maxlen/sizeof(unsigned int) integer
* values from/to the user buffer, treated as an ASCII string.
*
* Returns 0 on success.
*/
int proc_dointvec(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return do_proc_dointvec(table,write,filp,buffer,lenp,1,OP_SET);
}
/*
* init may raise the set.
*/
int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
if (!capable(CAP_SYS_MODULE)) {
return -EPERM;
}
return do_proc_dointvec(table,write,filp,buffer,lenp,1,
(current->pid == 1) ? OP_SET : OP_AND);
}
/**
* proc_dointvec_minmax - read a vector of integers with min/max values
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes up to table->maxlen/sizeof(unsigned int) integer
* values from/to the user buffer, treated as an ASCII string.
*
* This routine will ensure the values are within the range specified by
* table->extra1 (min) and table->extra2 (max).
*
* Returns 0 on success.
*/
int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
int *i, *min, *max, vleft, first=1, neg, val;
size_t len, left;
#define TMPBUFLEN 20
char buf[TMPBUFLEN], *p;
if (!table->data || !table->maxlen || !*lenp ||
(filp->f_pos && !write)) {
*lenp = 0;
return 0;
}
i = (int *) table->data;
min = (int *) table->extra1;
max = (int *) table->extra2;
vleft = table->maxlen / sizeof(int);
left = *lenp;
for (; left && vleft--; i++, first=0) {
if (write) {
while (left) {
char c;
if (get_user(c, (char *) buffer))
return -EFAULT;
if (!isspace(c))
break;
left--;
((char *) buffer)++;
}
if (!left)
break;
neg = 0;
len = left;
if (len > TMPBUFLEN-1)
len = TMPBUFLEN-1;
if(copy_from_user(buf, buffer, len))
return -EFAULT;
buf[len] = 0;
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
left--, p++;
}
if (*p < '0' || *p > '9')
break;
val = simple_strtoul(p, &p, 0);
len = p-buf;
if ((len < left) && *p && !isspace(*p))
break;
if (neg)
val = -val;
buffer += len;
left -= len;
if (min && val < *min++)
continue;
if (max && val > *max++)
continue;
*i = val;
} else {
p = buf;
if (!first)
*p++ = '\t';
sprintf(p, "%d", *i);
len = strlen(buf);
if (len > left)
len = left;
if(copy_to_user(buffer, buf, len))
return -EFAULT;
left -= len;
buffer += len;
}
}
if (!write && !first && left) {
if(put_user('\n', (char *) buffer))
return -EFAULT;
left--, buffer++;
}
if (write) {
p = (char *) buffer;
while (left) {
char c;
if (get_user(c, p++))
return -EFAULT;
if (!isspace(c))
break;
left--;
}
}
if (write && first)
return -EINVAL;
*lenp -= left;
filp->f_pos += *lenp;
return 0;
}
static int do_proc_doulongvec_minmax(ctl_table *table, int write,
struct file *filp,
void *buffer, size_t *lenp,
unsigned long convmul,
unsigned long convdiv)
{
#define TMPBUFLEN 20
unsigned long *i, *min, *max, val;
int vleft, first=1, neg;
size_t len, left;
char buf[TMPBUFLEN], *p;
if (!table->data || !table->maxlen || !*lenp ||
(filp->f_pos && !write)) {
*lenp = 0;
return 0;
}
i = (unsigned long *) table->data;
min = (unsigned long *) table->extra1;
max = (unsigned long *) table->extra2;
vleft = table->maxlen / sizeof(unsigned long);
left = *lenp;
for (; left && vleft--; i++, first=0) {
if (write) {
while (left) {
char c;
if (get_user(c, (char *) buffer))
return -EFAULT;
if (!isspace(c))
break;
left--;
((char *) buffer)++;
}
if (!left)
break;
neg = 0;
len = left;
if (len > TMPBUFLEN-1)
len = TMPBUFLEN-1;
if(copy_from_user(buf, buffer, len))
return -EFAULT;
buf[len] = 0;
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
left--, p++;
}
if (*p < '0' || *p > '9')
break;
val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
len = p-buf;
if ((len < left) && *p && !isspace(*p))
break;
if (neg)
val = -val;
buffer += len;
left -= len;
if(neg)
continue;
if (min && val < *min++)
continue;
if (max && val > *max++)
continue;
*i = val;
} else {
p = buf;
if (!first)
*p++ = '\t';
sprintf(p, "%lu", convdiv * (*i) / convmul);
len = strlen(buf);
if (len > left)
len = left;
if(copy_to_user(buffer, buf, len))
return -EFAULT;
left -= len;
buffer += len;
}
}
if (!write && !first && left) {
if(put_user('\n', (char *) buffer))
return -EFAULT;
left--, buffer++;
}
if (write) {
p = (char *) buffer;
while (left) {
char c;
if (get_user(c, p++))
return -EFAULT;
if (!isspace(c))
break;
left--;
}
}
if (write && first)
return -EINVAL;
*lenp -= left;
filp->f_pos += *lenp;
return 0;
#undef TMPBUFLEN
}
/**
* proc_doulongvec_minmax - read a vector of long integers with min/max values
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
* values from/to the user buffer, treated as an ASCII string.
*
* This routine will ensure the values are within the range specified by
* table->extra1 (min) and table->extra2 (max).
*
* Returns 0 on success.
*/
int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, 1l, 1l);
}
/**
* proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
* values from/to the user buffer, treated as an ASCII string. The values
* are treated as milliseconds, and converted to jiffies when they are stored.
*
* This routine will ensure the values are within the range specified by
* table->extra1 (min) and table->extra2 (max).
*
* Returns 0 on success.
*/
int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
struct file *filp,
void *buffer, size_t *lenp)
{
return do_proc_doulongvec_minmax(table, write, filp, buffer,
lenp, HZ, 1000l);
}
/**
* proc_dointvec_jiffies - read a vector of integers as seconds
* @table: the sysctl table
* @write: %TRUE if this is a write to the sysctl file
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
*
* Reads/writes up to table->maxlen/sizeof(unsigned int) integer
* values from/to the user buffer, treated as an ASCII string.
* The values read are assumed to be in seconds, and are converted into
* jiffies.
*
* Returns 0 on success.
*/
int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return do_proc_dointvec(table,write,filp,buffer,lenp,HZ,OP_SET);
}
#else /* CONFIG_PROC_FS */
int proc_dostring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
#endif /* CONFIG_PROC_FS */
/*
* General sysctl support routines
*/
/* The generic string strategy routine: */
int sysctl_string(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
size_t l, len;
if (!table->data || !table->maxlen)
return -ENOTDIR;
if (oldval && oldlenp) {
if (get_user(len, oldlenp))
return -EFAULT;
if (len) {
l = strlen(table->data);
if (len > l) len = l;
if (len >= table->maxlen)
len = table->maxlen;
if(copy_to_user(oldval, table->data, len))
return -EFAULT;
if(put_user(0, ((char *) oldval) + len))
return -EFAULT;
if(put_user(len, oldlenp))
return -EFAULT;
}
}
if (newval && newlen) {
len = newlen;
if (len > table->maxlen)
len = table->maxlen;
if(copy_from_user(table->data, newval, len))
return -EFAULT;
if (len == table->maxlen)
len--;
((char *) table->data)[len] = 0;
}
return 0;
}
/*
* This function makes sure that all of the integers in the vector
* are between the minimum and maximum values given in the arrays
* table->extra1 and table->extra2, respectively.
*/
int sysctl_intvec(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
int i, *vec, *min, *max;
size_t length;
if (newval && newlen) {
if (newlen % sizeof(int) != 0)
return -EINVAL;
if (!table->extra1 && !table->extra2)
return 0;
if (newlen > table->maxlen)
newlen = table->maxlen;
length = newlen / sizeof(int);
vec = (int *) newval;
min = (int *) table->extra1;
max = (int *) table->extra2;
for (i = 0; i < length; i++) {
int value;
if (get_user(value, vec + i))
return -EFAULT;
if (min && value < min[i])
return -EINVAL;
if (max && value > max[i])
return -EINVAL;
}
}
return 0;
}
/* Strategy function to convert jiffies to seconds */
int sysctl_jiffies(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
if (oldval) {
size_t olen;
if (oldlenp) {
if (get_user(olen, oldlenp))
return -EFAULT;
if (olen!=sizeof(int))
return -EINVAL;
}
if (put_user(*(int *)(table->data) / HZ, (int *)oldval) ||
(oldlenp && put_user(sizeof(int),oldlenp)))
return -EFAULT;
}
if (newval && newlen) {
int new;
if (newlen != sizeof(int))
return -EINVAL;
if (get_user(new, (int *)newval))
return -EFAULT;
*(int *)(table->data) = new*HZ;
}
return 1;
}
#else /* CONFIG_SYSCTL */
extern asmlinkage long sys_sysctl(struct __sysctl_args *args)
{
return -ENOSYS;
}
int sysctl_string(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
return -ENOSYS;
}
int sysctl_intvec(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
return -ENOSYS;
}
int sysctl_jiffies(ctl_table *table, int *name, int nlen,
void *oldval, size_t *oldlenp,
void *newval, size_t newlen, void **context)
{
return -ENOSYS;
}
int proc_dostring(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
struct file *filp,
void *buffer, size_t *lenp)
{
return -ENOSYS;
}
struct ctl_table_header * register_sysctl_table(ctl_table * table,
int insert_at_head)
{
return 0;
}
void unregister_sysctl_table(struct ctl_table_header * table)
{
}
#endif /* CONFIG_SYSCTL */
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