sysctl: use names instead of magic numbers.

Replace magic numbers with symbols for internal sysctl operations.
Convert in-kernel and libc consumers.

Submitted by:	Pawel Biernacki
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D21693

diff --git a/lib/libc/gen/sysctlnametomib.c b/lib/libc/gen/sysctlnametomib.c
index f01be37a0d7748efac620a98b14ee381971b1a87..86e02e98f9e343528f83178eb7df9b74733d97bd 100644 (file)
--- a/lib/libc/gen/sysctlnametomib.c
+++ b/lib/libc/gen/sysctlnametomib.c
@@ -47,8 +47,8 @@ sysctlnametomib(const char *name, int *mibp, size_t *sizep)
        int oid[2];
        int error;
 
-       oid[0] = 0;
-       oid[1] = 3;
+       oid[0] = CTL_SYSCTL;
+       oid[1] = CTL_SYSCTL_NAME2OID;
 
        *sizep *= sizeof(int);
        error = sysctl(oid, 2, mibp, sizep, name, strlen(name));

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 2ccfc4324fab76075b6ce1223a9d14961a477b97..e7f1319eaa149096ea87df8c01300a56a3ddfc8b 100644 (file)
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -935,13 +935,18 @@ SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, NULL);
  * (be aware though, that the proper interface isn't as obvious as it
  * may seem, there are various conflicting requirements.
  *
- * {0,0}       printf the entire MIB-tree.
- * {0,1,...}   return the name of the "..." OID.
- * {0,2,...}   return the next OID.
- * {0,3}       return the OID of the name in "new"
- * {0,4,...}   return the kind & format info for the "..." OID.
- * {0,5,...}   return the description of the "..." OID.
- * {0,6,...}   return the aggregation label of the "..." OID.
+ * {CTL_SYSCTL, CTL_SYSCTL_DEBUG}              printf the entire MIB-tree.
+ * {CTL_SYSCTL, CTL_SYSCTL_NAME, ...}          return the name of the "..."
+ *                                             OID.
+ * {CTL_SYSCTL, CTL_SYSCTL_NEXT, ...}          return the next OID.
+ * {CTL_SYSCTL, CTL_SYSCTL_NAME2OID}           return the OID of the name in
+ *                                             "new"
+ * {CTL_SYSCTL, CTL_SYSCTL_OIDFMT, ...}                return the kind & format info
+ *                                             for the "..." OID.
+ * {CTL_SYSCTL, CTL_SYSCTL_OIDDESCR, ...}      return the description of the
+ *                                             "..." OID.
+ * {CTL_SYSCTL, CTL_SYSCTL_OIDLABEL, ...}      return the aggregation label of
+ *                                             the "..." OID.
  */
 
 #ifdef SYSCTL_DEBUG
@@ -1009,8 +1014,8 @@ sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS)
        return (ENOENT);
 }
 
-SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
-       0, 0, sysctl_sysctl_debug, "-", "");
+SYSCTL_PROC(_sysctl, CTL_SYSCTL_DEBUG, debug, CTLTYPE_STRING | CTLFLAG_RD |
+    CTLFLAG_MPSAFE, 0, 0, sysctl_sysctl_debug, "-", "");
 #endif
 
 static int
@@ -1075,8 +1080,8 @@ sysctl_sysctl_name(SYSCTL_HANDLER_ARGS)
  * XXXRW/JA: Shouldn't return name data for nodes that we don't permit in
  * capability mode.
  */
-static SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
-    sysctl_sysctl_name, "");
+static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NAME, name, CTLFLAG_RD |
+    CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_name, "");
 
 static int
 sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 
@@ -1162,8 +1167,8 @@ sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
  * XXXRW/JA: Shouldn't return next data for nodes that we don't permit in
  * capability mode.
  */
-static SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD,
-    sysctl_sysctl_next, "");
+static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NEXT, next, CTLFLAG_RD |
+    CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_next, "");
 
 static int
 name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp)
@@ -1249,9 +1254,9 @@ sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
  * XXXRW/JA: Shouldn't return name2oid data for nodes that we don't permit in
  * capability mode.
  */
-SYSCTL_PROC(_sysctl, 3, name2oid,
-    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_MPSAFE
-    | CTLFLAG_CAPRW, 0, 0, sysctl_sysctl_name2oid, "I", "");
+SYSCTL_PROC(_sysctl, CTL_SYSCTL_NAME2OID, name2oid, CTLTYPE_INT | CTLFLAG_RW |
+    CTLFLAG_ANYBODY | CTLFLAG_MPSAFE | CTLFLAG_CAPRW, 0, 0,
+    sysctl_sysctl_name2oid, "I", "");
 
 static int
 sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
@@ -1279,8 +1284,8 @@ sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
 }
 
 
-static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
-    sysctl_sysctl_oidfmt, "");
+static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDFMT, oidfmt, CTLFLAG_RD |
+    CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidfmt, "");
 
 static int
 sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
@@ -1304,8 +1309,8 @@ sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS)
        return (error);
 }
 
-static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD,
-    sysctl_sysctl_oiddescr, "");
+static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDDESCR, oiddescr, CTLFLAG_RD |
+    CTLFLAG_MPSAFE|CTLFLAG_CAPRD, sysctl_sysctl_oiddescr, "");
 
 static int
 sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS)
@@ -1329,8 +1334,8 @@ sysctl_sysctl_oidlabel(SYSCTL_HANDLER_ARGS)
        return (error);
 }
 
-static SYSCTL_NODE(_sysctl, 6, oidlabel,
-    CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, "");
+static SYSCTL_NODE(_sysctl, CTL_SYSCTL_OIDLABEL, oidlabel, CTLFLAG_RD |
+    CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_oidlabel, "");
 
 /*
  * Default "handler" functions.
@@ -1857,8 +1862,8 @@ kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp,
         size_t oidlen, plen;
        int error;
 
-       oid[0] = 0;             /* sysctl internal magic */
-       oid[1] = 3;             /* name2oid */
+       oid[0] = CTL_SYSCTL;
+       oid[1] = CTL_SYSCTL_NAME2OID;
        oidlen = sizeof(oid);
 
        error = kernel_sysctl(td, oid, 2, oid, &oidlen,
@@ -2165,8 +2170,8 @@ kern___sysctlbyname(struct thread *td, const char *oname, size_t namelen,
        if (error != 0)
                goto out;
 
-       oid[0] = 0;
-       oid[1] = 3;
+       oid[0] = CTL_SYSCTL;
+       oid[1] = CTL_SYSCTL_NAME2OID;
        oidlen = sizeof(oid);
        error = kernel_sysctl(td, oid, 2, oid, &oidlen, (void *)name, namelen,
            retval, flags);
@@ -2667,8 +2672,8 @@ db_show_sysctl_all(int *oid, size_t len, int flags)
        int name1[CTL_MAXNAME + 2], name2[CTL_MAXNAME + 2];
        size_t l1, l2;
 
-       name1[0] = 0;
-       name1[1] = 2;
+       name1[0] = CTL_SYSCTL;
+       name1[1] = CTL_SYSCTL_NEXT;
        l1 = 2;
        if (len) {
                memcpy(name1+2, oid, len * sizeof(int));

diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 74976be5eba749b639ab642e3bacb137a5dfa1c1..e2facf8a133934d1f2b1ad52fa48173d3f9a2ce9 100644 (file)
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -889,7 +889,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry);
 /*
  * Top-level identifiers
  */
-#define        CTL_UNSPEC      0               /* unused */
+#define        CTL_SYSCTL      0               /* "magic" numbers */
 #define        CTL_KERN        1               /* "high kernel": proc, limits */
 #define        CTL_VM          2               /* virtual memory */
 #define        CTL_VFS         3               /* filesystem, mount type is next */
@@ -900,6 +900,17 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry);
 #define        CTL_USER        8               /* user-level */
 #define        CTL_P1003_1B    9               /* POSIX 1003.1B */
 
+/*
+ * CTL_SYSCTL identifiers
+ */
+#define        CTL_SYSCTL_DEBUG        0       /* printf all nodes */
+#define        CTL_SYSCTL_NAME         1       /* string name of OID */
+#define        CTL_SYSCTL_NEXT         2       /* next OID */
+#define        CTL_SYSCTL_NAME2OID     3       /* int array of name */
+#define        CTL_SYSCTL_OIDFMT       4       /* OID's kind and format */
+#define        CTL_SYSCTL_OIDDESCR     5       /* OID's description */
+#define        CTL_SYSCTL_OIDLABEL     6       /* aggregation label */
+
 /*
  * CTL_KERN identifiers
  */