/*- * Copyright (c) 2006 Robert N. M. Watson * Copyright (c) 2008-2009 Apple, Inc. * All rights reserved. * * This software was developed by Robert Watson for the TrustedBSD Project. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Implementation of a clonable special device providing a live stream of BSM * audit data. Consumers receive a "tee" of the system audit trail by * default, but may also define alternative event selections using ioctls. * This interface provides unreliable but timely access to audit events. * Consumers should be very careful to avoid introducing event cycles. */ /* * Memory types. */ static MALLOC_DEFINE(M_AUDIT_PIPE, "audit_pipe", "Audit pipes"); static MALLOC_DEFINE(M_AUDIT_PIPE_ENTRY, "audit_pipeent", "Audit pipe entries and buffers"); static MALLOC_DEFINE(M_AUDIT_PIPE_PRESELECT, "audit_pipe_presel", "Audit pipe preselection structure"); /* * Audit pipe buffer parameters. */ #define AUDIT_PIPE_QLIMIT_DEFAULT (128) #define AUDIT_PIPE_QLIMIT_MIN (1) #define AUDIT_PIPE_QLIMIT_MAX (1024) /* * Description of an entry in an audit_pipe. */ struct audit_pipe_entry { void *ape_record; u_int ape_record_len; TAILQ_ENTRY(audit_pipe_entry) ape_queue; }; /* * Audit pipes allow processes to express "interest" in the set of records * that are delivered via the pipe. They do this in a similar manner to the * mechanism for audit trail configuration, by expressing two global masks, * and optionally expressing per-auid masks. The following data structure is * the per-auid mask description. The global state is stored in the audit * pipe data structure. * * We may want to consider a more space/time-efficient data structure once * usage patterns for per-auid specifications are clear. */ struct audit_pipe_preselect { au_id_t app_auid; au_mask_t app_mask; TAILQ_ENTRY(audit_pipe_preselect) app_list; }; /* * Description of an individual audit_pipe. Consists largely of a bounded * length queue. */ #define AUDIT_PIPE_ASYNC 0x00000001 #define AUDIT_PIPE_NBIO 0x00000002 struct audit_pipe { u_int ap_flags; struct selinfo ap_selinfo; struct sigio *ap_sigio; /* * Per-pipe mutex protecting most fields in this data structure. */ struct mtx ap_mtx; /* * Per-pipe sleep lock serializing user-generated reads and flushes. * uiomove() is called to copy out the current head record's data * while the record remains in the queue, so we prevent other threads * from removing it using this lock. */ struct sx ap_sx; /* * Condition variable to signal when data has been delivered to a * pipe. */ struct cv ap_cv; /* * Various queue-reated variables: qlen and qlimit are a count of * records in the queue; qbyteslen is the number of bytes of data * across all records, and qoffset is the amount read so far of the * first record in the queue. The number of bytes available for * reading in the queue is qbyteslen - qoffset. */ u_int ap_qlen; u_int ap_qlimit; u_int ap_qbyteslen; u_int ap_qoffset; /* * Per-pipe operation statistics. */ u_int64_t ap_inserts; /* Records added. */ u_int64_t ap_reads; /* Records read. */ u_int64_t ap_drops; /* Records dropped. */ /* * Fields relating to pipe interest: global masks for unmatched * processes (attributable, non-attributable), and a list of specific * interest specifications by auid. */ int ap_preselect_mode; au_mask_t ap_preselect_flags; au_mask_t ap_preselect_naflags; TAILQ_HEAD(, audit_pipe_preselect) ap_preselect_list; /* * Current pending record list. Protected by a combination of ap_mtx * and ap_sx. Note particularly that *both* locks are required to * remove a record from the head of the queue, as an in-progress read * may sleep while copying and therefore cannot hold ap_mtx. */ TAILQ_HEAD(, audit_pipe_entry) ap_queue; /* * Global pipe list. */ TAILQ_ENTRY(audit_pipe) ap_list; }; #define AUDIT_PIPE_LOCK(ap) mtx_lock(&(ap)->ap_mtx) #define AUDIT_PIPE_LOCK_ASSERT(ap) mtx_assert(&(ap)->ap_mtx, MA_OWNED) #define AUDIT_PIPE_LOCK_DESTROY(ap) mtx_destroy(&(ap)->ap_mtx) #define AUDIT_PIPE_LOCK_INIT(ap) mtx_init(&(ap)->ap_mtx, \ "audit_pipe_mtx", NULL, MTX_DEF) #define AUDIT_PIPE_UNLOCK(ap) mtx_unlock(&(ap)->ap_mtx) #define AUDIT_PIPE_MTX(ap) (&(ap)->ap_mtx) #define AUDIT_PIPE_SX_LOCK_DESTROY(ap) sx_destroy(&(ap)->ap_sx) #define AUDIT_PIPE_SX_LOCK_INIT(ap) sx_init(&(ap)->ap_sx, "audit_pipe_sx") #define AUDIT_PIPE_SX_XLOCK_ASSERT(ap) sx_assert(&(ap)->ap_sx, SA_XLOCKED) #define AUDIT_PIPE_SX_XLOCK_SIG(ap) sx_xlock_sig(&(ap)->ap_sx) #define AUDIT_PIPE_SX_XUNLOCK(ap) sx_xunlock(&(ap)->ap_sx) /* * Global list of audit pipes, rwlock to protect it. Individual record * queues on pipes are protected by per-pipe locks; these locks synchronize * between threads walking the list to deliver to individual pipes and add/ * remove of pipes, and are mostly acquired for read. */ static TAILQ_HEAD(, audit_pipe) audit_pipe_list; static struct rwlock audit_pipe_lock; #define AUDIT_PIPE_LIST_LOCK_INIT() rw_init(&audit_pipe_lock, \ "audit_pipe_list_lock") #define AUDIT_PIPE_LIST_LOCK_DESTROY() rw_destroy(&audit_pipe_lock) #define AUDIT_PIPE_LIST_RLOCK() rw_rlock(&audit_pipe_lock) #define AUDIT_PIPE_LIST_RUNLOCK() rw_runlock(&audit_pipe_lock) #define AUDIT_PIPE_LIST_WLOCK() rw_wlock(&audit_pipe_lock) #define AUDIT_PIPE_LIST_WLOCK_ASSERT() rw_assert(&audit_pipe_lock, \ RA_WLOCKED) #define AUDIT_PIPE_LIST_WUNLOCK() rw_wunlock(&audit_pipe_lock) /* * Audit pipe device. */ static struct cdev *audit_pipe_dev; #define AUDIT_PIPE_NAME "auditpipe" /* * Special device methods and definition. */ static d_open_t audit_pipe_open; static d_close_t audit_pipe_close; static d_read_t audit_pipe_read; static d_ioctl_t audit_pipe_ioctl; static d_poll_t audit_pipe_poll; static d_kqfilter_t audit_pipe_kqfilter; static struct cdevsw audit_pipe_cdevsw = { .d_version = D_VERSION, .d_open = audit_pipe_open, .d_close = audit_pipe_close, .d_read = audit_pipe_read, .d_ioctl = audit_pipe_ioctl, .d_poll = audit_pipe_poll, .d_kqfilter = audit_pipe_kqfilter, .d_name = AUDIT_PIPE_NAME, }; static int audit_pipe_kqread(struct knote *note, long hint); static void audit_pipe_kqdetach(struct knote *note); static struct filterops audit_pipe_read_filterops = { .f_isfd = 1, .f_attach = NULL, .f_detach = audit_pipe_kqdetach, .f_event = audit_pipe_kqread, }; /* * Some global statistics on audit pipes. */ static int audit_pipe_count; /* Current number of pipes. */ static u_int64_t audit_pipe_ever; /* Pipes ever allocated. */ static u_int64_t audit_pipe_records; /* Records seen. */ static u_int64_t audit_pipe_drops; /* Global record drop count. */ /* * Free an audit pipe entry. */ static void audit_pipe_entry_free(struct audit_pipe_entry *ape) { free(ape->ape_record, M_AUDIT_PIPE_ENTRY); free(ape, M_AUDIT_PIPE_ENTRY); } /* * Find an audit pipe preselection specification for an auid, if any. */ static struct audit_pipe_preselect * audit_pipe_preselect_find(struct audit_pipe *ap, au_id_t auid) { struct audit_pipe_preselect *app; AUDIT_PIPE_LOCK_ASSERT(ap); TAILQ_FOREACH(app, &ap->ap_preselect_list, app_list) { if (app->app_auid == auid) return (app); } return (NULL); } /* * Query the per-pipe mask for a specific auid. */ static int audit_pipe_preselect_get(struct audit_pipe *ap, au_id_t auid, au_mask_t *maskp) { struct audit_pipe_preselect *app; int error; AUDIT_PIPE_LOCK(ap); app = audit_pipe_preselect_find(ap, auid); if (app != NULL) { *maskp = app->app_mask; error = 0; } else error = ENOENT; AUDIT_PIPE_UNLOCK(ap); return (error); } /* * Set the per-pipe mask for a specific auid. Add a new entry if needed; * otherwise, update the current entry. */ static void audit_pipe_preselect_set(struct audit_pipe *ap, au_id_t auid, au_mask_t mask) { struct audit_pipe_preselect *app, *app_new; /* * Pessimistically assume that the auid doesn't already have a mask * set, and allocate. We will free it if it is unneeded. */ app_new = malloc(sizeof(*app_new), M_AUDIT_PIPE_PRESELECT, M_WAITOK); AUDIT_PIPE_LOCK(ap); app = audit_pipe_preselect_find(ap, auid); if (app == NULL) { app = app_new; app_new = NULL; app->app_auid = auid; TAILQ_INSERT_TAIL(&ap->ap_preselect_list, app, app_list); } app->app_mask = mask; AUDIT_PIPE_UNLOCK(ap); if (app_new != NULL) free(app_new, M_AUDIT_PIPE_PRESELECT); } /* * Delete a per-auid mask on an audit pipe. */ static int audit_pipe_preselect_delete(struct audit_pipe *ap, au_id_t auid) { struct audit_pipe_preselect *app; int error; AUDIT_PIPE_LOCK(ap); app = audit_pipe_preselect_find(ap, auid); if (app != NULL) { TAILQ_REMOVE(&ap->ap_preselect_list, app, app_list); error = 0; } else error = ENOENT; AUDIT_PIPE_UNLOCK(ap); if (app != NULL) free(app, M_AUDIT_PIPE_PRESELECT); return (error); } /* * Delete all per-auid masks on an audit pipe. */ static void audit_pipe_preselect_flush_locked(struct audit_pipe *ap) { struct audit_pipe_preselect *app; AUDIT_PIPE_LOCK_ASSERT(ap); while ((app = TAILQ_FIRST(&ap->ap_preselect_list)) != NULL) { TAILQ_REMOVE(&ap->ap_preselect_list, app, app_list); free(app, M_AUDIT_PIPE_PRESELECT); } } static void audit_pipe_preselect_flush(struct audit_pipe *ap) { AUDIT_PIPE_LOCK(ap); audit_pipe_preselect_flush_locked(ap); AUDIT_PIPE_UNLOCK(ap); } /*- * Determine whether a specific audit pipe matches a record with these * properties. Algorithm is as follows: * * - If the pipe is configured to track the default trail configuration, then * use the results of global preselection matching. * - If not, search for a specifically configured auid entry matching the * event. If an entry is found, use that. * - Otherwise, use the default flags or naflags configured for the pipe. */ static int audit_pipe_preselect_check(struct audit_pipe *ap, au_id_t auid, au_event_t event, au_class_t class, int sorf, int trail_preselect) { struct audit_pipe_preselect *app; AUDIT_PIPE_LOCK_ASSERT(ap); switch (ap->ap_preselect_mode) { case AUDITPIPE_PRESELECT_MODE_TRAIL: return (trail_preselect); case AUDITPIPE_PRESELECT_MODE_LOCAL: app = audit_pipe_preselect_find(ap, auid); if (app == NULL) { if (auid == AU_DEFAUDITID) return (au_preselect(event, class, &ap->ap_preselect_naflags, sorf)); else return (au_preselect(event, class, &ap->ap_preselect_flags, sorf)); } else return (au_preselect(event, class, &app->app_mask, sorf)); default: panic("audit_pipe_preselect_check: mode %d", ap->ap_preselect_mode); } return (0); } /* * Determine whether there exists a pipe interested in a record with specific * properties. */ int audit_pipe_preselect(au_id_t auid, au_event_t event, au_class_t class, int sorf, int trail_preselect) { struct audit_pipe *ap; /* Lockless read to avoid acquiring the global lock if not needed. */ if (TAILQ_EMPTY(&audit_pipe_list)) return (0); AUDIT_PIPE_LIST_RLOCK(); TAILQ_FOREACH(ap, &audit_pipe_list, ap_list) { AUDIT_PIPE_LOCK(ap); if (audit_pipe_preselect_check(ap, auid, event, class, sorf, trail_preselect)) { AUDIT_PIPE_UNLOCK(ap); AUDIT_PIPE_LIST_RUNLOCK(); return (1); } AUDIT_PIPE_UNLOCK(ap); } AUDIT_PIPE_LIST_RUNLOCK(); return (0); } /* * Append individual record to a queue -- allocate queue-local buffer, and * add to the queue. If the queue is full or we can't allocate memory, drop * the newest record. */ static void audit_pipe_append(struct audit_pipe *ap, void *record, u_int record_len) { struct audit_pipe_entry *ape; AUDIT_PIPE_LOCK_ASSERT(ap); if (ap->ap_qlen >= ap->ap_qlimit) { ap->ap_drops++; audit_pipe_drops++; return; } ape = malloc(sizeof(*ape), M_AUDIT_PIPE_ENTRY, M_NOWAIT | M_ZERO); if (ape == NULL) { ap->ap_drops++; audit_pipe_drops++; return; } ape->ape_record = malloc(record_len, M_AUDIT_PIPE_ENTRY, M_NOWAIT); if (ape->ape_record == NULL) { free(ape, M_AUDIT_PIPE_ENTRY); ap->ap_drops++; audit_pipe_drops++; return; } bcopy(record, ape->ape_record, record_len); ape->ape_record_len = record_len; TAILQ_INSERT_TAIL(&ap->ap_queue, ape, ape_queue); ap->ap_inserts++; ap->ap_qlen++; ap->ap_qbyteslen += ape->ape_record_len; selwakeuppri(&ap->ap_selinfo, PSOCK); KNOTE_LOCKED(&ap->ap_selinfo.si_note, 0); if (ap->ap_flags & AUDIT_PIPE_ASYNC) pgsigio(&ap->ap_sigio, SIGIO, 0); cv_broadcast(&ap->ap_cv); } /* * audit_pipe_submit(): audit_worker submits audit records via this * interface, which arranges for them to be delivered to pipe queues. */ void audit_pipe_submit(au_id_t auid, au_event_t event, au_class_t class, int sorf, int trail_select, void *record, u_int record_len) { struct audit_pipe *ap; /* * Lockless read to avoid lock overhead if pipes are not in use. */ if (TAILQ_FIRST(&audit_pipe_list) == NULL) return; AUDIT_PIPE_LIST_RLOCK(); TAILQ_FOREACH(ap, &audit_pipe_list, ap_list) { AUDIT_PIPE_LOCK(ap); if (audit_pipe_preselect_check(ap, auid, event, class, sorf, trail_select)) audit_pipe_append(ap, record, record_len); AUDIT_PIPE_UNLOCK(ap); } AUDIT_PIPE_LIST_RUNLOCK(); /* Unlocked increment. */ audit_pipe_records++; } /* * audit_pipe_submit_user(): the same as audit_pipe_submit(), except that * since we don't currently have selection information available, it is * delivered to the pipe unconditionally. * * XXXRW: This is a bug. The BSM check routine for submitting a user record * should parse that information and return it. */ void audit_pipe_submit_user(void *record, u_int record_len) { struct audit_pipe *ap; /* * Lockless read to avoid lock overhead if pipes are not in use. */ if (TAILQ_FIRST(&audit_pipe_list) == NULL) return; AUDIT_PIPE_LIST_RLOCK(); TAILQ_FOREACH(ap, &audit_pipe_list, ap_list) { AUDIT_PIPE_LOCK(ap); audit_pipe_append(ap, record, record_len); AUDIT_PIPE_UNLOCK(ap); } AUDIT_PIPE_LIST_RUNLOCK(); /* Unlocked increment. */ audit_pipe_records++; } /* * Allocate a new audit pipe. Connects the pipe, on success, to the global * list and updates statistics. */ static struct audit_pipe * audit_pipe_alloc(void) { struct audit_pipe *ap; ap = malloc(sizeof(*ap), M_AUDIT_PIPE, M_NOWAIT | M_ZERO); if (ap == NULL) return (NULL); ap->ap_qlimit = AUDIT_PIPE_QLIMIT_DEFAULT; TAILQ_INIT(&ap->ap_queue); knlist_init_mtx(&ap->ap_selinfo.si_note, AUDIT_PIPE_MTX(ap)); AUDIT_PIPE_LOCK_INIT(ap); AUDIT_PIPE_SX_LOCK_INIT(ap); cv_init(&ap->ap_cv, "audit_pipe"); /* * Default flags, naflags, and auid-specific preselection settings to * 0. Initialize the mode to the global trail so that if praudit(1) * is run on /dev/auditpipe, it sees events associated with the * default trail. Pipe-aware application can clear the flag, set * custom masks, and flush the pipe as needed. */ bzero(&ap->ap_preselect_flags, sizeof(ap->ap_preselect_flags)); bzero(&ap->ap_preselect_naflags, sizeof(ap->ap_preselect_naflags)); TAILQ_INIT(&ap->ap_preselect_list); ap->ap_preselect_mode = AUDITPIPE_PRESELECT_MODE_TRAIL; /* * Add to global list and update global statistics. */ AUDIT_PIPE_LIST_WLOCK(); TAILQ_INSERT_HEAD(&audit_pipe_list, ap, ap_list); audit_pipe_count++; audit_pipe_ever++; AUDIT_PIPE_LIST_WUNLOCK(); return (ap); } /* * Flush all records currently present in an audit pipe; assume mutex is held. */ static void audit_pipe_flush(struct audit_pipe *ap) { struct audit_pipe_entry *ape; AUDIT_PIPE_LOCK_ASSERT(ap); while ((ape = TAILQ_FIRST(&ap->ap_queue)) != NULL) { TAILQ_REMOVE(&ap->ap_queue, ape, ape_queue); ap->ap_qbyteslen -= ape->ape_record_len; audit_pipe_entry_free(ape); ap->ap_qlen--; } ap->ap_qoffset = 0; KASSERT(ap->ap_qlen == 0, ("audit_pipe_free: ap_qbyteslen")); KASSERT(ap->ap_qbyteslen == 0, ("audit_pipe_flush: ap_qbyteslen")); } /* * Free an audit pipe; this means freeing all preselection state and all * records in the pipe. Assumes global write lock and pipe mutex are held to * prevent any new records from being inserted during the free, and that the * audit pipe is still on the global list. */ static void audit_pipe_free(struct audit_pipe *ap) { AUDIT_PIPE_LIST_WLOCK_ASSERT(); AUDIT_PIPE_LOCK_ASSERT(ap); audit_pipe_preselect_flush_locked(ap); audit_pipe_flush(ap); cv_destroy(&ap->ap_cv); AUDIT_PIPE_SX_LOCK_DESTROY(ap); AUDIT_PIPE_LOCK_DESTROY(ap); seldrain(&ap->ap_selinfo); knlist_destroy(&ap->ap_selinfo.si_note); TAILQ_REMOVE(&audit_pipe_list, ap, ap_list); free(ap, M_AUDIT_PIPE); audit_pipe_count--; } static void audit_pipe_dtor(void *arg) { struct audit_pipe *ap; ap = arg; AUDIT_PIPE_LIST_WLOCK(); AUDIT_PIPE_LOCK(ap); audit_pipe_free(ap); AUDIT_PIPE_LIST_WUNLOCK(); } /* * Audit pipe open method. Explicit privilege check isn't used as this * allows file permissions on the special device to be used to grant audit * review access. Those file permissions should be managed carefully. */ static int audit_pipe_open(struct cdev *dev, int oflags, int devtype, struct thread *td) { struct audit_pipe *ap; int error; ap = audit_pipe_alloc(); if (ap == NULL) { return (ENOMEM); } fsetown(td->td_proc->p_pid, &ap->ap_sigio); error = devfs_set_cdevpriv(ap, audit_pipe_dtor); if (error != 0) { AUDIT_PIPE_LIST_WLOCK(); audit_pipe_free(ap); AUDIT_PIPE_LIST_WUNLOCK(); } return (0); } /* * Close audit pipe, tear down all records, etc. */ static int audit_pipe_close(struct cdev *dev, int fflag, int devtype, struct thread *td) { struct audit_pipe *ap; int error; error = devfs_get_cdevpriv((void **)&ap); if (error != 0) return (error); funsetown(&ap->ap_sigio); return (0); } /* * Audit pipe ioctl() routine. Handle file descriptor and audit pipe layer * commands. */ static int audit_pipe_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) { struct auditpipe_ioctl_preselect *aip; struct audit_pipe *ap; au_mask_t *maskp; int error, mode; au_id_t auid; error = devfs_get_cdevpriv((void **)&ap); if (error != 0) return (error); /* * Audit pipe ioctls: first come standard device node ioctls, then * manipulation of pipe settings, and finally, statistics query * ioctls. */ switch (cmd) { case FIONBIO: AUDIT_PIPE_LOCK(ap); if (*(int *)data) ap->ap_flags |= AUDIT_PIPE_NBIO; else ap->ap_flags &= ~AUDIT_PIPE_NBIO; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case FIONREAD: AUDIT_PIPE_LOCK(ap); *(int *)data = ap->ap_qbyteslen - ap->ap_qoffset; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case FIOASYNC: AUDIT_PIPE_LOCK(ap); if (*(int *)data) ap->ap_flags |= AUDIT_PIPE_ASYNC; else ap->ap_flags &= ~AUDIT_PIPE_ASYNC; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case FIOSETOWN: error = fsetown(*(int *)data, &ap->ap_sigio); break; case FIOGETOWN: *(int *)data = fgetown(&ap->ap_sigio); error = 0; break; case AUDITPIPE_GET_QLEN: *(u_int *)data = ap->ap_qlen; error = 0; break; case AUDITPIPE_GET_QLIMIT: *(u_int *)data = ap->ap_qlimit; error = 0; break; case AUDITPIPE_SET_QLIMIT: /* Lockless integer write. */ if (*(u_int *)data >= AUDIT_PIPE_QLIMIT_MIN || *(u_int *)data <= AUDIT_PIPE_QLIMIT_MAX) { ap->ap_qlimit = *(u_int *)data; error = 0; } else error = EINVAL; break; case AUDITPIPE_GET_QLIMIT_MIN: *(u_int *)data = AUDIT_PIPE_QLIMIT_MIN; error = 0; break; case AUDITPIPE_GET_QLIMIT_MAX: *(u_int *)data = AUDIT_PIPE_QLIMIT_MAX; error = 0; break; case AUDITPIPE_GET_PRESELECT_FLAGS: AUDIT_PIPE_LOCK(ap); maskp = (au_mask_t *)data; *maskp = ap->ap_preselect_flags; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case AUDITPIPE_SET_PRESELECT_FLAGS: AUDIT_PIPE_LOCK(ap); maskp = (au_mask_t *)data; ap->ap_preselect_flags = *maskp; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case AUDITPIPE_GET_PRESELECT_NAFLAGS: AUDIT_PIPE_LOCK(ap); maskp = (au_mask_t *)data; *maskp = ap->ap_preselect_naflags; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case AUDITPIPE_SET_PRESELECT_NAFLAGS: AUDIT_PIPE_LOCK(ap); maskp = (au_mask_t *)data; ap->ap_preselect_naflags = *maskp; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case AUDITPIPE_GET_PRESELECT_AUID: aip = (struct auditpipe_ioctl_preselect *)data; error = audit_pipe_preselect_get(ap, aip->aip_auid, &aip->aip_mask); break; case AUDITPIPE_SET_PRESELECT_AUID: aip = (struct auditpipe_ioctl_preselect *)data; audit_pipe_preselect_set(ap, aip->aip_auid, aip->aip_mask); error = 0; break; case AUDITPIPE_DELETE_PRESELECT_AUID: auid = *(au_id_t *)data; error = audit_pipe_preselect_delete(ap, auid); break; case AUDITPIPE_FLUSH_PRESELECT_AUID: audit_pipe_preselect_flush(ap); error = 0; break; case AUDITPIPE_GET_PRESELECT_MODE: AUDIT_PIPE_LOCK(ap); *(int *)data = ap->ap_preselect_mode; AUDIT_PIPE_UNLOCK(ap); error = 0; break; case AUDITPIPE_SET_PRESELECT_MODE: mode = *(int *)data; switch (mode) { case AUDITPIPE_PRESELECT_MODE_TRAIL: case AUDITPIPE_PRESELECT_MODE_LOCAL: AUDIT_PIPE_LOCK(ap); ap->ap_preselect_mode = mode; AUDIT_PIPE_UNLOCK(ap); error = 0; break; default: error = EINVAL; } break; case AUDITPIPE_FLUSH: if (AUDIT_PIPE_SX_XLOCK_SIG(ap) != 0) return (EINTR); AUDIT_PIPE_LOCK(ap); audit_pipe_flush(ap); AUDIT_PIPE_UNLOCK(ap); AUDIT_PIPE_SX_XUNLOCK(ap); error = 0; break; case AUDITPIPE_GET_MAXAUDITDATA: *(u_int *)data = MAXAUDITDATA; error = 0; break; case AUDITPIPE_GET_INSERTS: *(u_int *)data = ap->ap_inserts; error = 0; break; case AUDITPIPE_GET_READS: *(u_int *)data = ap->ap_reads; error = 0; break; case AUDITPIPE_GET_DROPS: *(u_int *)data = ap->ap_drops; error = 0; break; case AUDITPIPE_GET_TRUNCATES: *(u_int *)data = 0; error = 0; break; default: error = ENOTTY; } return (error); } /* * Audit pipe read. Read one or more partial or complete records to user * memory. */ static int audit_pipe_read(struct cdev *dev, struct uio *uio, int flag) { struct audit_pipe_entry *ape; struct audit_pipe *ap; u_int toread; int error; error = devfs_get_cdevpriv((void **)&ap); if (error != 0) return (error); /* * We hold an sx(9) lock over read and flush because we rely on the * stability of a record in the queue during uiomove(9). */ if (AUDIT_PIPE_SX_XLOCK_SIG(ap) != 0) return (EINTR); AUDIT_PIPE_LOCK(ap); while (TAILQ_EMPTY(&ap->ap_queue)) { if (ap->ap_flags & AUDIT_PIPE_NBIO) { AUDIT_PIPE_UNLOCK(ap); AUDIT_PIPE_SX_XUNLOCK(ap); return (EAGAIN); } error = cv_wait_sig(&ap->ap_cv, AUDIT_PIPE_MTX(ap)); if (error) { AUDIT_PIPE_UNLOCK(ap); AUDIT_PIPE_SX_XUNLOCK(ap); return (error); } } /* * Copy as many remaining bytes from the current record to userspace * as we can. Keep processing records until we run out of records in * the queue, or until the user buffer runs out of space. * * Note: we rely on the SX lock to maintain ape's stability here. */ ap->ap_reads++; while ((ape = TAILQ_FIRST(&ap->ap_queue)) != NULL && uio->uio_resid > 0) { AUDIT_PIPE_LOCK_ASSERT(ap); KASSERT(ape->ape_record_len > ap->ap_qoffset, ("audit_pipe_read: record_len > qoffset (1)")); toread = MIN(ape->ape_record_len - ap->ap_qoffset, uio->uio_resid); AUDIT_PIPE_UNLOCK(ap); error = uiomove((char *)ape->ape_record + ap->ap_qoffset, toread, uio); if (error) { AUDIT_PIPE_SX_XUNLOCK(ap); return (error); } /* * If the copy succeeded, update book-keeping, and if no * bytes remain in the current record, free it. */ AUDIT_PIPE_LOCK(ap); KASSERT(TAILQ_FIRST(&ap->ap_queue) == ape, ("audit_pipe_read: queue out of sync after uiomove")); ap->ap_qoffset += toread; KASSERT(ape->ape_record_len >= ap->ap_qoffset, ("audit_pipe_read: record_len >= qoffset (2)")); if (ap->ap_qoffset == ape->ape_record_len) { TAILQ_REMOVE(&ap->ap_queue, ape, ape_queue); ap->ap_qbyteslen -= ape->ape_record_len; audit_pipe_entry_free(ape); ap->ap_qlen--; ap->ap_qoffset = 0; } } AUDIT_PIPE_UNLOCK(ap); AUDIT_PIPE_SX_XUNLOCK(ap); return (0); } /* * Audit pipe poll. */ static int audit_pipe_poll(struct cdev *dev, int events, struct thread *td) { struct audit_pipe *ap; int error, revents; revents = 0; error = devfs_get_cdevpriv((void **)&ap); if (error != 0) return (error); if (events & (POLLIN | POLLRDNORM)) { AUDIT_PIPE_LOCK(ap); if (TAILQ_FIRST(&ap->ap_queue) != NULL) revents |= events & (POLLIN | POLLRDNORM); else selrecord(td, &ap->ap_selinfo); AUDIT_PIPE_UNLOCK(ap); } return (revents); } /* * Audit pipe kqfilter. */ static int audit_pipe_kqfilter(struct cdev *dev, struct knote *kn) { struct audit_pipe *ap; int error; error = devfs_get_cdevpriv((void **)&ap); if (error != 0) return (error); if (kn->kn_filter != EVFILT_READ) return (EINVAL); kn->kn_fop = &audit_pipe_read_filterops; kn->kn_hook = ap; AUDIT_PIPE_LOCK(ap); knlist_add(&ap->ap_selinfo.si_note, kn, 1); AUDIT_PIPE_UNLOCK(ap); return (0); } /* * Return true if there are records available for reading on the pipe. */ static int audit_pipe_kqread(struct knote *kn, long hint) { struct audit_pipe *ap; ap = (struct audit_pipe *)kn->kn_hook; AUDIT_PIPE_LOCK_ASSERT(ap); if (ap->ap_qlen != 0) { kn->kn_data = ap->ap_qbyteslen - ap->ap_qoffset; return (1); } else { kn->kn_data = 0; return (0); } } /* * Detach kqueue state from audit pipe. */ static void audit_pipe_kqdetach(struct knote *kn) { struct audit_pipe *ap; ap = (struct audit_pipe *)kn->kn_hook; AUDIT_PIPE_LOCK(ap); knlist_remove(&ap->ap_selinfo.si_note, kn, 1); AUDIT_PIPE_UNLOCK(ap); } /* * Initialize the audit pipe system. */ static void audit_pipe_init(void *unused) { TAILQ_INIT(&audit_pipe_list); AUDIT_PIPE_LIST_LOCK_INIT(); audit_pipe_dev = make_dev(&audit_pipe_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "%s", AUDIT_PIPE_NAME); if (audit_pipe_dev == NULL) { AUDIT_PIPE_LIST_LOCK_DESTROY(); panic("Can't initialize audit pipe subsystem"); } } SYSINIT(audit_pipe_init, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, audit_pipe_init, NULL);