/*- * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Mike Karels at Berkeley Software Design, Inc. * * Quite extensively rewritten by Poul-Henning Kamp of the FreeBSD * project, to make these variables more userfriendly. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_compat.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include static MALLOC_DEFINE(M_SYSCTL, "sysctl", "sysctl internal magic"); static MALLOC_DEFINE(M_SYSCTLOID, "sysctloid", "sysctl dynamic oids"); static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer"); /* * The sysctllock protects the MIB tree. It also protects sysctl * contexts used with dynamic sysctls. The sysctl_register_oid() and * sysctl_unregister_oid() routines require the sysctllock to already * be held, so the sysctl_xlock() and sysctl_xunlock() routines are * provided for the few places in the kernel which need to use that * API rather than using the dynamic API. Use of the dynamic API is * strongly encouraged for most code. * * The sysctlmemlock is used to limit the amount of user memory wired for * sysctl requests. This is implemented by serializing any userland * sysctl requests larger than a single page via an exclusive lock. */ static struct sx sysctllock; static struct sx sysctlmemlock; #define SYSCTL_XLOCK() sx_xlock(&sysctllock) #define SYSCTL_XUNLOCK() sx_xunlock(&sysctllock) #define SYSCTL_SLOCK() sx_slock(&sysctllock) #define SYSCTL_SUNLOCK() sx_sunlock(&sysctllock) #define SYSCTL_XLOCKED() sx_xlocked(&sysctllock) #define SYSCTL_ASSERT_LOCKED() sx_assert(&sysctllock, SA_LOCKED) #define SYSCTL_ASSERT_XLOCKED() sx_assert(&sysctllock, SA_XLOCKED) #define SYSCTL_ASSERT_SLOCKED() sx_assert(&sysctllock, SA_SLOCKED) #define SYSCTL_INIT() sx_init(&sysctllock, "sysctl lock") #define SYSCTL_SLEEP(ch, wmesg, timo) \ sx_sleep(ch, &sysctllock, 0, wmesg, timo) static int sysctl_root(SYSCTL_HANDLER_ARGS); /* Root list */ struct sysctl_oid_list sysctl__children = SLIST_HEAD_INITIALIZER(&sysctl__children); static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse); static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t); static int sysctl_new_kernel(struct sysctl_req *, void *, size_t); static void sysctl_lock(bool xlock) { if (xlock) SYSCTL_XLOCK(); else SYSCTL_SLOCK(); } static bool sysctl_unlock(void) { bool xlocked; xlocked = SYSCTL_XLOCKED(); if (xlocked) SYSCTL_XUNLOCK(); else SYSCTL_SUNLOCK(); return (xlocked); } static struct sysctl_oid * sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) { struct sysctl_oid *oidp; SYSCTL_ASSERT_LOCKED(); SLIST_FOREACH(oidp, list, oid_link) { if (strcmp(oidp->oid_name, name) == 0) { return (oidp); } } return (NULL); } /* * Initialization of the MIB tree. * * Order by number in each list. */ void sysctl_xlock(void) { SYSCTL_XLOCK(); } void sysctl_xunlock(void) { SYSCTL_XUNLOCK(); } static int sysctl_root_handler_locked(struct sysctl_oid *oid, void *arg1, intptr_t arg2, struct sysctl_req *req) { int error; bool xlocked; if (oid->oid_kind & CTLFLAG_DYN) atomic_add_int(&oid->oid_running, 1); xlocked = sysctl_unlock(); if (!(oid->oid_kind & CTLFLAG_MPSAFE)) mtx_lock(&Giant); error = oid->oid_handler(oid, arg1, arg2, req); if (!(oid->oid_kind & CTLFLAG_MPSAFE)) mtx_unlock(&Giant); sysctl_lock(xlocked); if (oid->oid_kind & CTLFLAG_DYN) { if (atomic_fetchadd_int(&oid->oid_running, -1) == 1 && (oid->oid_kind & CTLFLAG_DYING) != 0) wakeup(&oid->oid_running); } return (error); } static void sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp) { struct sysctl_req req; struct sysctl_oid *curr; char *penv = NULL; char path[64]; ssize_t rem = sizeof(path); ssize_t len; int val_int; long val_long; int64_t val_64; quad_t val_quad; int error; path[--rem] = 0; for (curr = oidp; curr != NULL; curr = SYSCTL_PARENT(curr)) { len = strlen(curr->oid_name); rem -= len; if (curr != oidp) rem -= 1; if (rem < 0) { printf("OID path exceeds %d bytes\n", (int)sizeof(path)); return; } memcpy(path + rem, curr->oid_name, len); if (curr != oidp) path[rem + len] = '.'; } memset(&req, 0, sizeof(req)); req.td = curthread; req.oldfunc = sysctl_old_kernel; req.newfunc = sysctl_new_kernel; req.lock = REQ_UNWIRED; switch (oidp->oid_kind & CTLTYPE) { case CTLTYPE_INT: if (getenv_int(path + rem, &val_int) == 0) return; req.newlen = sizeof(val_int); req.newptr = &val_int; break; case CTLTYPE_UINT: if (getenv_uint(path + rem, (unsigned int *)&val_int) == 0) return; req.newlen = sizeof(val_int); req.newptr = &val_int; break; case CTLTYPE_LONG: if (getenv_long(path + rem, &val_long) == 0) return; req.newlen = sizeof(val_long); req.newptr = &val_long; break; case CTLTYPE_ULONG: if (getenv_ulong(path + rem, (unsigned long *)&val_long) == 0) return; req.newlen = sizeof(val_long); req.newptr = &val_long; break; case CTLTYPE_S64: if (getenv_quad(path + rem, &val_quad) == 0) return; val_64 = val_quad; req.newlen = sizeof(val_64); req.newptr = &val_64; break; case CTLTYPE_U64: /* XXX there is no getenv_uquad() */ if (getenv_quad(path + rem, &val_quad) == 0) return; val_64 = val_quad; req.newlen = sizeof(val_64); req.newptr = &val_64; break; case CTLTYPE_STRING: penv = kern_getenv(path + rem); if (penv == NULL) return; req.newlen = strlen(penv); req.newptr = penv; break; default: return; } error = sysctl_root_handler_locked(oidp, oidp->oid_arg1, oidp->oid_arg2, &req); if (error != 0) printf("Setting sysctl %s failed: %d\n", path + rem, error); if (penv != NULL) freeenv(penv); } void sysctl_register_oid(struct sysctl_oid *oidp) { struct sysctl_oid_list *parent = oidp->oid_parent; struct sysctl_oid *p; struct sysctl_oid *q; int oid_number; int timeout = 2; /* * First check if another oid with the same name already * exists in the parent's list. */ SYSCTL_ASSERT_XLOCKED(); p = sysctl_find_oidname(oidp->oid_name, parent); if (p != NULL) { if ((p->oid_kind & CTLTYPE) == CTLTYPE_NODE) { p->oid_refcnt++; return; } else { printf("can't re-use a leaf (%s)!\n", p->oid_name); return; } } /* get current OID number */ oid_number = oidp->oid_number; #if (OID_AUTO >= 0) #error "OID_AUTO is expected to be a negative value" #endif /* * Any negative OID number qualifies as OID_AUTO. Valid OID * numbers should always be positive. * * NOTE: DO NOT change the starting value here, change it in * , and make sure it is at least 256 to * accomodate e.g. net.inet.raw as a static sysctl node. */ if (oid_number < 0) { static int newoid; /* * By decrementing the next OID number we spend less * time inserting the OIDs into a sorted list. */ if (--newoid < CTL_AUTO_START) newoid = 0x7fffffff; oid_number = newoid; } /* * Insert the OID into the parent's list sorted by OID number. */ retry: q = NULL; SLIST_FOREACH(p, parent, oid_link) { /* check if the current OID number is in use */ if (oid_number == p->oid_number) { /* get the next valid OID number */ if (oid_number < CTL_AUTO_START || oid_number == 0x7fffffff) { /* wraparound - restart */ oid_number = CTL_AUTO_START; /* don't loop forever */ if (!timeout--) panic("sysctl: Out of OID numbers\n"); goto retry; } else { oid_number++; } } else if (oid_number < p->oid_number) break; q = p; } /* check for non-auto OID number collision */ if (oidp->oid_number >= 0 && oidp->oid_number < CTL_AUTO_START && oid_number >= CTL_AUTO_START) { printf("sysctl: OID number(%d) is already in use for '%s'\n", oidp->oid_number, oidp->oid_name); } /* update the OID number, if any */ oidp->oid_number = oid_number; if (q != NULL) SLIST_INSERT_AFTER(q, oidp, oid_link); else SLIST_INSERT_HEAD(parent, oidp, oid_link); if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE && #ifdef VIMAGE (oidp->oid_kind & CTLFLAG_VNET) == 0 && #endif (oidp->oid_kind & CTLFLAG_TUN) != 0 && (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) { /* only fetch value once */ oidp->oid_kind |= CTLFLAG_NOFETCH; /* try to fetch value from kernel environment */ sysctl_load_tunable_by_oid_locked(oidp); } } void sysctl_unregister_oid(struct sysctl_oid *oidp) { struct sysctl_oid *p; int error; SYSCTL_ASSERT_XLOCKED(); error = ENOENT; if (oidp->oid_number == OID_AUTO) { error = EINVAL; } else { SLIST_FOREACH(p, oidp->oid_parent, oid_link) { if (p == oidp) { SLIST_REMOVE(oidp->oid_parent, oidp, sysctl_oid, oid_link); error = 0; break; } } } /* * This can happen when a module fails to register and is * being unloaded afterwards. It should not be a panic() * for normal use. */ if (error) printf("%s: failed to unregister sysctl\n", __func__); } /* Initialize a new context to keep track of dynamically added sysctls. */ int sysctl_ctx_init(struct sysctl_ctx_list *c) { if (c == NULL) { return (EINVAL); } /* * No locking here, the caller is responsible for not adding * new nodes to a context until after this function has * returned. */ TAILQ_INIT(c); return (0); } /* Free the context, and destroy all dynamic oids registered in this context */ int sysctl_ctx_free(struct sysctl_ctx_list *clist) { struct sysctl_ctx_entry *e, *e1; int error; error = 0; /* * First perform a "dry run" to check if it's ok to remove oids. * XXX FIXME * XXX This algorithm is a hack. But I don't know any * XXX better solution for now... */ SYSCTL_XLOCK(); TAILQ_FOREACH(e, clist, link) { error = sysctl_remove_oid_locked(e->entry, 0, 0); if (error) break; } /* * Restore deregistered entries, either from the end, * or from the place where error occured. * e contains the entry that was not unregistered */ if (error) e1 = TAILQ_PREV(e, sysctl_ctx_list, link); else e1 = TAILQ_LAST(clist, sysctl_ctx_list); while (e1 != NULL) { sysctl_register_oid(e1->entry); e1 = TAILQ_PREV(e1, sysctl_ctx_list, link); } if (error) { SYSCTL_XUNLOCK(); return(EBUSY); } /* Now really delete the entries */ e = TAILQ_FIRST(clist); while (e != NULL) { e1 = TAILQ_NEXT(e, link); error = sysctl_remove_oid_locked(e->entry, 1, 0); if (error) panic("sysctl_remove_oid: corrupt tree, entry: %s", e->entry->oid_name); free(e, M_SYSCTLOID); e = e1; } SYSCTL_XUNLOCK(); return (error); } /* Add an entry to the context */ struct sysctl_ctx_entry * sysctl_ctx_entry_add(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) { struct sysctl_ctx_entry *e; SYSCTL_ASSERT_XLOCKED(); if (clist == NULL || oidp == NULL) return(NULL); e = malloc(sizeof(struct sysctl_ctx_entry), M_SYSCTLOID, M_WAITOK); e->entry = oidp; TAILQ_INSERT_HEAD(clist, e, link); return (e); } /* Find an entry in the context */ struct sysctl_ctx_entry * sysctl_ctx_entry_find(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) { struct sysctl_ctx_entry *e; SYSCTL_ASSERT_XLOCKED(); if (clist == NULL || oidp == NULL) return(NULL); TAILQ_FOREACH(e, clist, link) { if(e->entry == oidp) return(e); } return (e); } /* * Delete an entry from the context. * NOTE: this function doesn't free oidp! You have to remove it * with sysctl_remove_oid(). */ int sysctl_ctx_entry_del(struct sysctl_ctx_list *clist, struct sysctl_oid *oidp) { struct sysctl_ctx_entry *e; if (clist == NULL || oidp == NULL) return (EINVAL); SYSCTL_XLOCK(); e = sysctl_ctx_entry_find(clist, oidp); if (e != NULL) { TAILQ_REMOVE(clist, e, link); SYSCTL_XUNLOCK(); free(e, M_SYSCTLOID); return (0); } else { SYSCTL_XUNLOCK(); return (ENOENT); } } /* * Remove dynamically created sysctl trees. * oidp - top of the tree to be removed * del - if 0 - just deregister, otherwise free up entries as well * recurse - if != 0 traverse the subtree to be deleted */ int sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse) { int error; SYSCTL_XLOCK(); error = sysctl_remove_oid_locked(oidp, del, recurse); SYSCTL_XUNLOCK(); return (error); } int sysctl_remove_name(struct sysctl_oid *parent, const char *name, int del, int recurse) { struct sysctl_oid *p, *tmp; int error; error = ENOENT; SYSCTL_XLOCK(); SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(parent), oid_link, tmp) { if (strcmp(p->oid_name, name) == 0) { error = sysctl_remove_oid_locked(p, del, recurse); break; } } SYSCTL_XUNLOCK(); return (error); } static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse) { struct sysctl_oid *p, *tmp; int error; SYSCTL_ASSERT_XLOCKED(); if (oidp == NULL) return(EINVAL); if ((oidp->oid_kind & CTLFLAG_DYN) == 0) { printf("can't remove non-dynamic nodes!\n"); return (EINVAL); } /* * WARNING: normal method to do this should be through * sysctl_ctx_free(). Use recursing as the last resort * method to purge your sysctl tree of leftovers... * However, if some other code still references these nodes, * it will panic. */ if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { if (oidp->oid_refcnt == 1) { SLIST_FOREACH_SAFE(p, SYSCTL_CHILDREN(oidp), oid_link, tmp) { if (!recurse) { printf("Warning: failed attempt to " "remove oid %s with child %s\n", oidp->oid_name, p->oid_name); return (ENOTEMPTY); } error = sysctl_remove_oid_locked(p, del, recurse); if (error) return (error); } } } if (oidp->oid_refcnt > 1 ) { oidp->oid_refcnt--; } else { if (oidp->oid_refcnt == 0) { printf("Warning: bad oid_refcnt=%u (%s)!\n", oidp->oid_refcnt, oidp->oid_name); return (EINVAL); } sysctl_unregister_oid(oidp); if (del) { /* * Wait for all threads running the handler to drain. * This preserves the previous behavior when the * sysctl lock was held across a handler invocation, * and is necessary for module unload correctness. */ while (oidp->oid_running > 0) { oidp->oid_kind |= CTLFLAG_DYING; SYSCTL_SLEEP(&oidp->oid_running, "oidrm", 0); } if (oidp->oid_descr) free(__DECONST(char *, oidp->oid_descr), M_SYSCTLOID); free(__DECONST(char *, oidp->oid_name), M_SYSCTLOID); free(oidp, M_SYSCTLOID); } } return (0); } /* * Create new sysctls at run time. * clist may point to a valid context initialized with sysctl_ctx_init(). */ struct sysctl_oid * sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent, int number, const char *name, int kind, void *arg1, intptr_t arg2, int (*handler)(SYSCTL_HANDLER_ARGS), const char *fmt, const char *descr) { struct sysctl_oid *oidp; /* You have to hook up somewhere.. */ if (parent == NULL) return(NULL); /* Check if the node already exists, otherwise create it */ SYSCTL_XLOCK(); oidp = sysctl_find_oidname(name, parent); if (oidp != NULL) { if ((oidp->oid_kind & CTLTYPE) == CTLTYPE_NODE) { oidp->oid_refcnt++; /* Update the context */ if (clist != NULL) sysctl_ctx_entry_add(clist, oidp); SYSCTL_XUNLOCK(); return (oidp); } else { SYSCTL_XUNLOCK(); printf("can't re-use a leaf (%s)!\n", name); return (NULL); } } oidp = malloc(sizeof(struct sysctl_oid), M_SYSCTLOID, M_WAITOK|M_ZERO); oidp->oid_parent = parent; SLIST_INIT(&oidp->oid_children); oidp->oid_number = number; oidp->oid_refcnt = 1; oidp->oid_name = strdup(name, M_SYSCTLOID); oidp->oid_handler = handler; oidp->oid_kind = CTLFLAG_DYN | kind; oidp->oid_arg1 = arg1; oidp->oid_arg2 = arg2; oidp->oid_fmt = fmt; if (descr != NULL) oidp->oid_descr = strdup(descr, M_SYSCTLOID); /* Update the context, if used */ if (clist != NULL) sysctl_ctx_entry_add(clist, oidp); /* Register this oid */ sysctl_register_oid(oidp); SYSCTL_XUNLOCK(); return (oidp); } /* * Rename an existing oid. */ void sysctl_rename_oid(struct sysctl_oid *oidp, const char *name) { char *newname; char *oldname; newname = strdup(name, M_SYSCTLOID); SYSCTL_XLOCK(); oldname = __DECONST(char *, oidp->oid_name); oidp->oid_name = newname; SYSCTL_XUNLOCK(); free(oldname, M_SYSCTLOID); } /* * Reparent an existing oid. */ int sysctl_move_oid(struct sysctl_oid *oid, struct sysctl_oid_list *parent) { struct sysctl_oid *oidp; SYSCTL_XLOCK(); if (oid->oid_parent == parent) { SYSCTL_XUNLOCK(); return (0); } oidp = sysctl_find_oidname(oid->oid_name, parent); if (oidp != NULL) { SYSCTL_XUNLOCK(); return (EEXIST); } sysctl_unregister_oid(oid); oid->oid_parent = parent; oid->oid_number = OID_AUTO; sysctl_register_oid(oid); SYSCTL_XUNLOCK(); return (0); } /* * Register the kernel's oids on startup. */ SET_DECLARE(sysctl_set, struct sysctl_oid); static void sysctl_register_all(void *arg) { struct sysctl_oid **oidp; sx_init(&sysctlmemlock, "sysctl mem"); SYSCTL_INIT(); SYSCTL_XLOCK(); SET_FOREACH(oidp, sysctl_set) sysctl_register_oid(*oidp); SYSCTL_XUNLOCK(); } SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, 0); /* * "Staff-functions" * * These functions implement a presently undocumented interface * used by the sysctl program to walk the tree, and get the type * so it can print the value. * This interface is under work and consideration, and should probably * be killed with a big axe by the first person who can find the time. * (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 the "..." OID. */ #ifdef SYSCTL_DEBUG static void sysctl_sysctl_debug_dump_node(struct sysctl_oid_list *l, int i) { int k; struct sysctl_oid *oidp; SYSCTL_ASSERT_LOCKED(); SLIST_FOREACH(oidp, l, oid_link) { for (k=0; koid_number, oidp->oid_name); printf("%c%c", oidp->oid_kind & CTLFLAG_RD ? 'R':' ', oidp->oid_kind & CTLFLAG_WR ? 'W':' '); if (oidp->oid_handler) printf(" *Handler"); switch (oidp->oid_kind & CTLTYPE) { case CTLTYPE_NODE: printf(" Node\n"); if (!oidp->oid_handler) { sysctl_sysctl_debug_dump_node( SYSCTL_CHILDREN(oidp), i + 2); } break; case CTLTYPE_INT: printf(" Int\n"); break; case CTLTYPE_UINT: printf(" u_int\n"); break; case CTLTYPE_LONG: printf(" Long\n"); break; case CTLTYPE_ULONG: printf(" u_long\n"); break; case CTLTYPE_STRING: printf(" String\n"); break; case CTLTYPE_U64: printf(" uint64_t\n"); break; case CTLTYPE_S64: printf(" int64_t\n"); break; case CTLTYPE_OPAQUE: printf(" Opaque/struct\n"); break; default: printf("\n"); } } } static int sysctl_sysctl_debug(SYSCTL_HANDLER_ARGS) { int error; error = priv_check(req->td, PRIV_SYSCTL_DEBUG); if (error) return (error); SYSCTL_SLOCK(); sysctl_sysctl_debug_dump_node(&sysctl__children, 0); SYSCTL_SUNLOCK(); return (ENOENT); } SYSCTL_PROC(_sysctl, 0, debug, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, 0, 0, sysctl_sysctl_debug, "-", ""); #endif static int sysctl_sysctl_name(SYSCTL_HANDLER_ARGS) { int *name = (int *) arg1; u_int namelen = arg2; int error = 0; struct sysctl_oid *oid; struct sysctl_oid_list *lsp = &sysctl__children, *lsp2; char buf[10]; SYSCTL_SLOCK(); while (namelen) { if (!lsp) { snprintf(buf,sizeof(buf),"%d",*name); if (req->oldidx) error = SYSCTL_OUT(req, ".", 1); if (!error) error = SYSCTL_OUT(req, buf, strlen(buf)); if (error) goto out; namelen--; name++; continue; } lsp2 = 0; SLIST_FOREACH(oid, lsp, oid_link) { if (oid->oid_number != *name) continue; if (req->oldidx) error = SYSCTL_OUT(req, ".", 1); if (!error) error = SYSCTL_OUT(req, oid->oid_name, strlen(oid->oid_name)); if (error) goto out; namelen--; name++; if ((oid->oid_kind & CTLTYPE) != CTLTYPE_NODE) break; if (oid->oid_handler) break; lsp2 = SYSCTL_CHILDREN(oid); break; } lsp = lsp2; } error = SYSCTL_OUT(req, "", 1); out: SYSCTL_SUNLOCK(); return (error); } /* * 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 int sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, int *next, int *len, int level, struct sysctl_oid **oidpp) { struct sysctl_oid *oidp; SYSCTL_ASSERT_LOCKED(); *len = level; SLIST_FOREACH(oidp, lsp, oid_link) { *next = oidp->oid_number; *oidpp = oidp; if (oidp->oid_kind & CTLFLAG_SKIP) continue; if (!namelen) { if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) return (0); if (oidp->oid_handler) /* We really should call the handler here...*/ return (0); lsp = SYSCTL_CHILDREN(oidp); if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, len, level+1, oidpp)) return (0); goto emptynode; } if (oidp->oid_number < *name) continue; if (oidp->oid_number > *name) { if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) return (0); if (oidp->oid_handler) return (0); lsp = SYSCTL_CHILDREN(oidp); if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, len, level+1, oidpp)) return (0); goto next; } if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) continue; if (oidp->oid_handler) continue; lsp = SYSCTL_CHILDREN(oidp); if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, len, level+1, oidpp)) return (0); next: namelen = 1; emptynode: *len = level; } return (1); } static int sysctl_sysctl_next(SYSCTL_HANDLER_ARGS) { int *name = (int *) arg1; u_int namelen = arg2; int i, j, error; struct sysctl_oid *oid; struct sysctl_oid_list *lsp = &sysctl__children; int newoid[CTL_MAXNAME]; SYSCTL_SLOCK(); i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid); SYSCTL_SUNLOCK(); if (i) return (ENOENT); error = SYSCTL_OUT(req, newoid, j * sizeof (int)); return (error); } /* * 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 int name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) { struct sysctl_oid *oidp; struct sysctl_oid_list *lsp = &sysctl__children; char *p; SYSCTL_ASSERT_LOCKED(); for (*len = 0; *len < CTL_MAXNAME;) { p = strsep(&name, "."); oidp = SLIST_FIRST(lsp); for (;; oidp = SLIST_NEXT(oidp, oid_link)) { if (oidp == NULL) return (ENOENT); if (strcmp(p, oidp->oid_name) == 0) break; } *oid++ = oidp->oid_number; (*len)++; if (name == NULL || *name == '\0') { if (oidpp) *oidpp = oidp; return (0); } if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) break; if (oidp->oid_handler) break; lsp = SYSCTL_CHILDREN(oidp); } return (ENOENT); } static int sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) { char *p; int error, oid[CTL_MAXNAME], len = 0; struct sysctl_oid *op = 0; if (!req->newlen) return (ENOENT); if (req->newlen >= MAXPATHLEN) /* XXX arbitrary, undocumented */ return (ENAMETOOLONG); p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK); error = SYSCTL_IN(req, p, req->newlen); if (error) { free(p, M_SYSCTL); return (error); } p [req->newlen] = '\0'; SYSCTL_SLOCK(); error = name2oid(p, oid, &len, &op); SYSCTL_SUNLOCK(); free(p, M_SYSCTL); if (error) return (error); error = SYSCTL_OUT(req, oid, len * sizeof *oid); return (error); } /* * 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", ""); static int sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) { struct sysctl_oid *oid; int error; SYSCTL_SLOCK(); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) goto out; if (oid->oid_fmt == NULL) { error = ENOENT; goto out; } error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind)); if (error) goto out; error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1); out: SYSCTL_SUNLOCK(); return (error); } static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, sysctl_sysctl_oidfmt, ""); static int sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) { struct sysctl_oid *oid; int error; SYSCTL_SLOCK(); error = sysctl_find_oid(arg1, arg2, &oid, NULL, req); if (error) goto out; if (oid->oid_descr == NULL) { error = ENOENT; goto out; } error = SYSCTL_OUT(req, oid->oid_descr, strlen(oid->oid_descr) + 1); out: SYSCTL_SUNLOCK(); return (error); } static SYSCTL_NODE(_sysctl, 5, oiddescr, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_CAPRD, sysctl_sysctl_oiddescr, ""); /* * Default "handler" functions. */ /* * Handle an int, signed or unsigned. * Two cases: * a variable: point arg1 at it. * a constant: pass it in arg2. */ int sysctl_handle_int(SYSCTL_HANDLER_ARGS) { int tmpout, error = 0; /* * Attempt to get a coherent snapshot by making a copy of the data. */ if (arg1) tmpout = *(int *)arg1; else tmpout = arg2; error = SYSCTL_OUT(req, &tmpout, sizeof(int)); if (error || !req->newptr) return (error); if (!arg1) error = EPERM; else error = SYSCTL_IN(req, arg1, sizeof(int)); return (error); } /* * Based on on sysctl_handle_int() convert milliseconds into ticks. * Note: this is used by TCP. */ int sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) { int error, s, tt; tt = *(int *)arg1; s = (int)((int64_t)tt * 1000 / hz); error = sysctl_handle_int(oidp, &s, 0, req); if (error || !req->newptr) return (error); tt = (int)((int64_t)s * hz / 1000); if (tt < 1) return (EINVAL); *(int *)arg1 = tt; return (0); } /* * Handle a long, signed or unsigned. * Two cases: * a variable: point arg1 at it. * a constant: pass it in arg2. */ int sysctl_handle_long(SYSCTL_HANDLER_ARGS) { int error = 0; long tmplong; #ifdef SCTL_MASK32 int tmpint; #endif /* * Attempt to get a coherent snapshot by making a copy of the data. */ if (arg1) tmplong = *(long *)arg1; else tmplong = arg2; #ifdef SCTL_MASK32 if (req->flags & SCTL_MASK32) { tmpint = tmplong; error = SYSCTL_OUT(req, &tmpint, sizeof(int)); } else #endif error = SYSCTL_OUT(req, &tmplong, sizeof(long)); if (error || !req->newptr) return (error); if (!arg1) error = EPERM; #ifdef SCTL_MASK32 else if (req->flags & SCTL_MASK32) { error = SYSCTL_IN(req, &tmpint, sizeof(int)); *(long *)arg1 = (long)tmpint; } #endif else error = SYSCTL_IN(req, arg1, sizeof(long)); return (error); } /* * Handle a 64 bit int, signed or unsigned. * Two cases: * a variable: point arg1 at it. * a constant: pass it in arg2. */ int sysctl_handle_64(SYSCTL_HANDLER_ARGS) { int error = 0; uint64_t tmpout; /* * Attempt to get a coherent snapshot by making a copy of the data. */ if (arg1) tmpout = *(uint64_t *)arg1; else tmpout = arg2; error = SYSCTL_OUT(req, &tmpout, sizeof(uint64_t)); if (error || !req->newptr) return (error); if (!arg1) error = EPERM; else error = SYSCTL_IN(req, arg1, sizeof(uint64_t)); return (error); } /* * Handle our generic '\0' terminated 'C' string. * Two cases: * a variable string: point arg1 at it, arg2 is max length. * a constant string: point arg1 at it, arg2 is zero. */ int sysctl_handle_string(SYSCTL_HANDLER_ARGS) { size_t outlen; int error = 0, ro_string = 0; /* * A zero-length buffer indicates a fixed size read-only * string: */ if (arg2 == 0) { arg2 = strlen((char *)arg1) + 1; ro_string = 1; } if (req->oldptr != NULL) { char *tmparg; if (ro_string) { tmparg = arg1; } else { /* try to make a coherent snapshot of the string */ tmparg = malloc(arg2, M_SYSCTLTMP, M_WAITOK); memcpy(tmparg, arg1, arg2); } outlen = strnlen(tmparg, arg2 - 1) + 1; error = SYSCTL_OUT(req, tmparg, outlen); if (!ro_string) free(tmparg, M_SYSCTLTMP); } else { outlen = strnlen((char *)arg1, arg2 - 1) + 1; error = SYSCTL_OUT(req, NULL, outlen); } if (error || !req->newptr) return (error); if ((req->newlen - req->newidx) >= arg2) { error = EINVAL; } else { arg2 = (req->newlen - req->newidx); error = SYSCTL_IN(req, arg1, arg2); ((char *)arg1)[arg2] = '\0'; } return (error); } /* * Handle any kind of opaque data. * arg1 points to it, arg2 is the size. */ int sysctl_handle_opaque(SYSCTL_HANDLER_ARGS) { int error, tries; u_int generation; struct sysctl_req req2; /* * Attempt to get a coherent snapshot, by using the thread * pre-emption counter updated from within mi_switch() to * determine if we were pre-empted during a bcopy() or * copyout(). Make 3 attempts at doing this before giving up. * If we encounter an error, stop immediately. */ tries = 0; req2 = *req; retry: generation = curthread->td_generation; error = SYSCTL_OUT(req, arg1, arg2); if (error) return (error); tries++; if (generation != curthread->td_generation && tries < 3) { *req = req2; goto retry; } error = SYSCTL_IN(req, arg1, arg2); return (error); } /* * Transfer functions to/from kernel space. * XXX: rather untested at this point */ static int sysctl_old_kernel(struct sysctl_req *req, const void *p, size_t l) { size_t i = 0; if (req->oldptr) { i = l; if (req->oldlen <= req->oldidx) i = 0; else if (i > req->oldlen - req->oldidx) i = req->oldlen - req->oldidx; if (i > 0) bcopy(p, (char *)req->oldptr + req->oldidx, i); } req->oldidx += l; if (req->oldptr && i != l) return (ENOMEM); return (0); } static int sysctl_new_kernel(struct sysctl_req *req, void *p, size_t l) { if (!req->newptr) return (0); if (req->newlen - req->newidx < l) return (EINVAL); bcopy((char *)req->newptr + req->newidx, p, l); req->newidx += l; return (0); } int kernel_sysctl(struct thread *td, int *name, u_int namelen, void *old, size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) { int error = 0; struct sysctl_req req; bzero(&req, sizeof req); req.td = td; req.flags = flags; if (oldlenp) { req.oldlen = *oldlenp; } req.validlen = req.oldlen; if (old) { req.oldptr= old; } if (new != NULL) { req.newlen = newlen; req.newptr = new; } req.oldfunc = sysctl_old_kernel; req.newfunc = sysctl_new_kernel; req.lock = REQ_UNWIRED; SYSCTL_SLOCK(); error = sysctl_root(0, name, namelen, &req); SYSCTL_SUNLOCK(); if (req.lock == REQ_WIRED && req.validlen > 0) vsunlock(req.oldptr, req.validlen); if (error && error != ENOMEM) return (error); if (retval) { if (req.oldptr && req.oldidx > req.validlen) *retval = req.validlen; else *retval = req.oldidx; } return (error); } int kernel_sysctlbyname(struct thread *td, char *name, void *old, size_t *oldlenp, void *new, size_t newlen, size_t *retval, int flags) { int oid[CTL_MAXNAME]; size_t oidlen, plen; int error; oid[0] = 0; /* sysctl internal magic */ oid[1] = 3; /* name2oid */ oidlen = sizeof(oid); error = kernel_sysctl(td, oid, 2, oid, &oidlen, (void *)name, strlen(name), &plen, flags); if (error) return (error); error = kernel_sysctl(td, oid, plen / sizeof(int), old, oldlenp, new, newlen, retval, flags); return (error); } /* * Transfer function to/from user space. */ static int sysctl_old_user(struct sysctl_req *req, const void *p, size_t l) { size_t i, len, origidx; int error; origidx = req->oldidx; req->oldidx += l; if (req->oldptr == NULL) return (0); /* * If we have not wired the user supplied buffer and we are currently * holding locks, drop a witness warning, as it's possible that * write operations to the user page can sleep. */ if (req->lock != REQ_WIRED) WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "sysctl_old_user()"); i = l; len = req->validlen; if (len <= origidx) i = 0; else { if (i > len - origidx) i = len - origidx; if (req->lock == REQ_WIRED) { error = copyout_nofault(p, (char *)req->oldptr + origidx, i); } else error = copyout(p, (char *)req->oldptr + origidx, i); if (error != 0) return (error); } if (i < l) return (ENOMEM); return (0); } static int sysctl_new_user(struct sysctl_req *req, void *p, size_t l) { int error; if (!req->newptr) return (0); if (req->newlen - req->newidx < l) return (EINVAL); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "sysctl_new_user()"); error = copyin((char *)req->newptr + req->newidx, p, l); req->newidx += l; return (error); } /* * Wire the user space destination buffer. If set to a value greater than * zero, the len parameter limits the maximum amount of wired memory. */ int sysctl_wire_old_buffer(struct sysctl_req *req, size_t len) { int ret; size_t wiredlen; wiredlen = (len > 0 && len < req->oldlen) ? len : req->oldlen; ret = 0; if (req->lock != REQ_WIRED && req->oldptr && req->oldfunc == sysctl_old_user) { if (wiredlen != 0) { ret = vslock(req->oldptr, wiredlen); if (ret != 0) { if (ret != ENOMEM) return (ret); wiredlen = 0; } } req->lock = REQ_WIRED; req->validlen = wiredlen; } return (0); } int sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid, int *nindx, struct sysctl_req *req) { struct sysctl_oid_list *lsp; struct sysctl_oid *oid; int indx; SYSCTL_ASSERT_LOCKED(); lsp = &sysctl__children; indx = 0; while (indx < CTL_MAXNAME) { SLIST_FOREACH(oid, lsp, oid_link) { if (oid->oid_number == name[indx]) break; } if (oid == NULL) return (ENOENT); indx++; if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { if (oid->oid_handler != NULL || indx == namelen) { *noid = oid; if (nindx != NULL) *nindx = indx; KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, ("%s found DYING node %p", __func__, oid)); return (0); } lsp = SYSCTL_CHILDREN(oid); } else if (indx == namelen) { *noid = oid; if (nindx != NULL) *nindx = indx; KASSERT((oid->oid_kind & CTLFLAG_DYING) == 0, ("%s found DYING node %p", __func__, oid)); return (0); } else { return (ENOTDIR); } } return (ENOENT); } /* * Traverse our tree, and find the right node, execute whatever it points * to, and return the resulting error code. */ static int sysctl_root(SYSCTL_HANDLER_ARGS) { struct sysctl_oid *oid; int error, indx, lvl; SYSCTL_ASSERT_SLOCKED(); error = sysctl_find_oid(arg1, arg2, &oid, &indx, req); if (error) return (error); if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { /* * You can't call a sysctl when it's a node, but has * no handler. Inform the user that it's a node. * The indx may or may not be the same as namelen. */ if (oid->oid_handler == NULL) return (EISDIR); } /* Is this sysctl writable? */ if (req->newptr && !(oid->oid_kind & CTLFLAG_WR)) return (EPERM); KASSERT(req->td != NULL, ("sysctl_root(): req->td == NULL")); #ifdef CAPABILITY_MODE /* * If the process is in capability mode, then don't permit reading or * writing unless specifically granted for the node. */ if (IN_CAPABILITY_MODE(req->td)) { if (req->oldptr && !(oid->oid_kind & CTLFLAG_CAPRD)) return (EPERM); if (req->newptr && !(oid->oid_kind & CTLFLAG_CAPWR)) return (EPERM); } #endif /* Is this sysctl sensitive to securelevels? */ if (req->newptr && (oid->oid_kind & CTLFLAG_SECURE)) { lvl = (oid->oid_kind & CTLMASK_SECURE) >> CTLSHIFT_SECURE; error = securelevel_gt(req->td->td_ucred, lvl); if (error) return (error); } /* Is this sysctl writable by only privileged users? */ if (req->newptr && !(oid->oid_kind & CTLFLAG_ANYBODY)) { int priv; if (oid->oid_kind & CTLFLAG_PRISON) priv = PRIV_SYSCTL_WRITEJAIL; #ifdef VIMAGE else if ((oid->oid_kind & CTLFLAG_VNET) && prison_owns_vnet(req->td->td_ucred)) priv = PRIV_SYSCTL_WRITEJAIL; #endif else priv = PRIV_SYSCTL_WRITE; error = priv_check(req->td, priv); if (error) return (error); } if (!oid->oid_handler) return (EINVAL); if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) { arg1 = (int *)arg1 + indx; arg2 -= indx; } else { arg1 = oid->oid_arg1; arg2 = oid->oid_arg2; } #ifdef MAC error = mac_system_check_sysctl(req->td->td_ucred, oid, arg1, arg2, req); if (error != 0) return (error); #endif #ifdef VIMAGE if ((oid->oid_kind & CTLFLAG_VNET) && arg1 != NULL) arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1); #endif error = sysctl_root_handler_locked(oid, arg1, arg2, req); KFAIL_POINT_ERROR(_debug_fail_point, sysctl_running, error); return (error); } #ifndef _SYS_SYSPROTO_H_ struct sysctl_args { int *name; u_int namelen; void *old; size_t *oldlenp; void *new; size_t newlen; }; #endif int sys___sysctl(struct thread *td, struct sysctl_args *uap) { int error, i, name[CTL_MAXNAME]; size_t j; if (uap->namelen > CTL_MAXNAME || uap->namelen < 2) return (EINVAL); error = copyin(uap->name, &name, uap->namelen * sizeof(int)); if (error) return (error); error = userland_sysctl(td, name, uap->namelen, uap->old, uap->oldlenp, 0, uap->new, uap->newlen, &j, 0); if (error && error != ENOMEM) return (error); if (uap->oldlenp) { i = copyout(&j, uap->oldlenp, sizeof(j)); if (i) return (i); } return (error); } /* * This is used from various compatibility syscalls too. That's why name * must be in kernel space. */ int userland_sysctl(struct thread *td, int *name, u_int namelen, void *old, size_t *oldlenp, int inkernel, void *new, size_t newlen, size_t *retval, int flags) { int error = 0, memlocked; struct sysctl_req req; bzero(&req, sizeof req); req.td = td; req.flags = flags; if (oldlenp) { if (inkernel) { req.oldlen = *oldlenp; } else { error = copyin(oldlenp, &req.oldlen, sizeof(*oldlenp)); if (error) return (error); } } req.validlen = req.oldlen; if (old) { if (!useracc(old, req.oldlen, VM_PROT_WRITE)) return (EFAULT); req.oldptr= old; } if (new != NULL) { if (!useracc(new, newlen, VM_PROT_READ)) return (EFAULT); req.newlen = newlen; req.newptr = new; } req.oldfunc = sysctl_old_user; req.newfunc = sysctl_new_user; req.lock = REQ_UNWIRED; #ifdef KTRACE if (KTRPOINT(curthread, KTR_SYSCTL)) ktrsysctl(name, namelen); #endif if (req.oldptr && req.oldlen > PAGE_SIZE) { memlocked = 1; sx_xlock(&sysctlmemlock); } else memlocked = 0; CURVNET_SET(TD_TO_VNET(td)); for (;;) { req.oldidx = 0; req.newidx = 0; SYSCTL_SLOCK(); error = sysctl_root(0, name, namelen, &req); SYSCTL_SUNLOCK(); if (error != EAGAIN) break; kern_yield(PRI_USER); } CURVNET_RESTORE(); if (req.lock == REQ_WIRED && req.validlen > 0) vsunlock(req.oldptr, req.validlen); if (memlocked) sx_xunlock(&sysctlmemlock); if (error && error != ENOMEM) return (error); if (retval) { if (req.oldptr && req.oldidx > req.validlen) *retval = req.validlen; else *retval = req.oldidx; } return (error); } /* * Drain into a sysctl struct. The user buffer should be wired if a page * fault would cause issue. */ static int sbuf_sysctl_drain(void *arg, const char *data, int len) { struct sysctl_req *req = arg; int error; error = SYSCTL_OUT(req, data, len); KASSERT(error >= 0, ("Got unexpected negative value %d", error)); return (error == 0 ? len : -error); } struct sbuf * sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length, struct sysctl_req *req) { /* Supply a default buffer size if none given. */ if (buf == NULL && length == 0) length = 64; s = sbuf_new(s, buf, length, SBUF_FIXEDLEN | SBUF_INCLUDENUL); sbuf_set_drain(s, sbuf_sysctl_drain, req); return (s); }