sysctl.c
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上传日期:2013-02-24
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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;
- }
- 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) {
- get_user(len, oldlenp);
- 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 %sn",
- 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 freen");
- 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;
- get_user(value, vec + i);
- 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 */