History

sysctl: Separate the binary sysctl logic into it's own file.

In preparation for more invasive cleanups separate the core binary sysctl logic into it's own file.

Eric W. Biederman committed 17 years ago

Commit afa588b1 parent b4191483 files · +186 −166Browse files

Showing the changes to kernel/sysctl_binary.c (1 of 3 files). Show all

Unified · Split

kernel/sysctl_binary.c+185−0
@@ -0,0 +1,185 @@
1+#include <linux/stat.h>
2+#include <linux/sysctl.h>
3+#include "../fs/xfs/linux-2.6/xfs_sysctl.h"
4+#include <linux/sunrpc/debug.h>
5+#include <linux/string.h>
6+#include <net/ip_vs.h>
7+#include <linux/syscalls.h>
8+#include <linux/namei.h>
9+#include <linux/mount.h>
10+#include <linux/fs.h>
11+#include <linux/nsproxy.h>
12+#include <linux/pid_namespace.h>
13+#include <linux/file.h>
14+#include <linux/ctype.h>
15+#include <linux/smp_lock.h>
16+
17+static int deprecated_sysctl_warning(struct __sysctl_args *args);
18+
19+#ifdef CONFIG_SYSCTL_SYSCALL
20+
21+/* Perform the actual read/write of a sysctl table entry. */
22+static int do_sysctl_strategy(struct ctl_table_root *root,
23+ struct ctl_table *table,
24+ void __user *oldval, size_t __user *oldlenp,
25+ void __user *newval, size_t newlen)
26+{
27+ int op = 0, rc;
28+
29+ if (oldval)
30+ op |= MAY_READ;
31+ if (newval)
32+ op |= MAY_WRITE;
33+ if (sysctl_perm(root, table, op))
34+ return -EPERM;
35+
36+ if (table->strategy) {
37+ rc = table->strategy(table, oldval, oldlenp, newval, newlen);
38+ if (rc < 0)
39+ return rc;
40+ if (rc > 0)
41+ return 0;
42+ }
43+
44+ /* If there is no strategy routine, or if the strategy returns
45+ * zero, proceed with automatic r/w */
46+ if (table->data && table->maxlen) {
47+ rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
48+ if (rc < 0)
49+ return rc;
50+ }
51+ return 0;
52+}
53+
54+static int parse_table(int __user *name, int nlen,
55+ void __user *oldval, size_t __user *oldlenp,
56+ void __user *newval, size_t newlen,
57+ struct ctl_table_root *root,
58+ struct ctl_table *table)
59+{
60+ int n;
61+repeat:
62+ if (!nlen)
63+ return -ENOTDIR;
64+ if (get_user(n, name))
65+ return -EFAULT;
66+ for ( ; table->ctl_name || table->procname; table++) {
67+ if (!table->ctl_name)
68+ continue;
69+ if (n == table->ctl_name) {
70+ int error;
71+ if (table->child) {
72+ if (sysctl_perm(root, table, MAY_EXEC))
73+ return -EPERM;
74+ name++;
75+ nlen--;
76+ table = table->child;
77+ goto repeat;
78+ }
79+ error = do_sysctl_strategy(root, table,
80+ oldval, oldlenp,
81+ newval, newlen);
82+ return error;
83+ }
84+ }
85+ return -ENOTDIR;
86+}
87+
88+int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
89+ void __user *newval, size_t newlen)
90+{
91+ struct ctl_table_header *head;
92+ int error = -ENOTDIR;
93+
94+ if (nlen <= 0 || nlen >= CTL_MAXNAME)
95+ return -ENOTDIR;
96+ if (oldval) {
97+ int old_len;
98+ if (!oldlenp || get_user(old_len, oldlenp))
99+ return -EFAULT;
100+ }
101+
102+ for (head = sysctl_head_next(NULL); head;
103+ head = sysctl_head_next(head)) {
104+ error = parse_table(name, nlen, oldval, oldlenp,
105+ newval, newlen,
106+ head->root, head->ctl_table);
107+ if (error != -ENOTDIR) {
108+ sysctl_head_finish(head);
109+ break;
110+ }
111+ }
112+ return error;
113+}
114+
115+SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
116+{
117+ struct __sysctl_args tmp;
118+ int error;
119+
120+ if (copy_from_user(&tmp, args, sizeof(tmp)))
121+ return -EFAULT;
122+
123+ error = deprecated_sysctl_warning(&tmp);
124+ if (error)
125+ goto out;
126+
127+ lock_kernel();
128+ error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
129+ tmp.newval, tmp.newlen);
130+ unlock_kernel();
131+out:
132+ return error;
133+}
134+
135+#else /* CONFIG_SYSCTL_SYSCALL */
136+
137+SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
138+{
139+ struct __sysctl_args tmp;
140+ int error;
141+
142+ if (copy_from_user(&tmp, args, sizeof(tmp)))
143+ return -EFAULT;
144+
145+ error = deprecated_sysctl_warning(&tmp);
146+
147+ /* If no error reading the parameters then just -ENOSYS ... */
148+ if (!error)
149+ error = -ENOSYS;
150+
151+ return error;
152+}
153+
154+#endif /* CONFIG_SYSCTL_SYSCALL */
155+
156+static int deprecated_sysctl_warning(struct __sysctl_args *args)
157+{
158+ static int msg_count;
159+ int name[CTL_MAXNAME];
160+ int i;
161+
162+ /* Check args->nlen. */
163+ if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
164+ return -ENOTDIR;
165+
166+ /* Read in the sysctl name for better debug message logging */
167+ for (i = 0; i < args->nlen; i++)
168+ if (get_user(name[i], args->name + i))
169+ return -EFAULT;
170+
171+ /* Ignore accesses to kernel.version */
172+ if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
173+ return 0;
174+
175+ if (msg_count < 5) {
176+ msg_count++;
177+ printk(KERN_INFO
178+ "warning: process `%s' used the deprecated sysctl "
179+ "system call with ", current->comm);
180+ for (i = 0; i < args->nlen; i++)
181+ printk("%d.", name[i]);
182+ printk("\n");
183+ }
184+ return 0;
185+}