/
evtloop.c
1661 lines (1559 loc) · 45.6 KB
/
evtloop.c
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/*-
* xnumon - monitor macOS for malicious activity
* https://www.roe.ch/xnumon
*
* Copyright (c) 2017-2019, Daniel Roethlisberger <daniel@roe.ch>.
* All rights reserved.
*
* Licensed under the Open Software License version 3.0.
*/
#include "evtloop.h"
#include "auclass.h"
#include "auevent.h"
#include "aupolicy.h"
#include "sys.h"
#include "str.h"
#include "time.h"
#include "os.h"
#include "policy.h"
#include "debug.h"
#include "attrib.h"
#include <sys/ptrace.h>
#include <stdint.h>
#include <inttypes.h>
#include <limits.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
#include <assert.h>
static bool running = true; /* shared */
static int kefd = -1; /* shared */
static FILE *auef = NULL;
static pid_t xnumon_pid;
static uint64_t aupclobbers = 0;
static uint64_t aueunknowns = 0;
static uint64_t failedsyscalls = 0;
static uint64_t radar38845422 = 0;
static uint64_t radar38845422_fatal = 0;
static uint64_t radar38845784 = 0; /* never fatal */
static uint64_t radar39267328 = 0;
static uint64_t radar39267328_fatal = 0;
static uint64_t radar39623812 = 0;
static uint64_t radar39623812_fatal = 0;
static uint64_t radar42770257_fatal = 0; /* always fatal */
static uint64_t radar42783724 = 0;
static uint64_t radar42783724_fatal = 0;
static uint64_t radar42784847 = 0;
static uint64_t radar42784847_fatal = 0;
static uint64_t radar42946744_fatal = 0;
static uint64_t radar43151662_fatal = 0; /* always fatal */
static uint64_t missingtoken = 0;
static uint64_t ooms = 0;
static bool kextloop_running = true;
static pthread_t kextloop_thr;
static int
kefd_readable(int fd, UNUSED void *udata) {
const xnumon_msg_t *msg;
struct timespec tm;
msg = kextctl_recv(fd);
if (!msg)
return -1;
tm.tv_sec = msg->time_s;
tm.tv_nsec = msg->time_ns;
procmon_kern_preexec(&tm, (pid_t)msg->pid, msg->path);
if (kextctl_ack(fd, msg) == -1) {
fprintf(stderr, "Failed to acknowledge message from kext\n");
return -1;
}
return 0;
}
static void *
kextloop_thread(void *arg) {
kqueue_t *kq = (kqueue_t *)arg;
#if 0 /* terra pericolosa */
(void)policy_thread_sched_priority(TP_HIGH);
#endif
(void)policy_thread_diskio_important();
/* event dispatch loop */
kextloop_running = true;
for (;;) {
int rv = kqueue_dispatch(kq);
if (!kextloop_running)
break;
if (rv != 0) {
fprintf(stderr, "kevent_dispatch() failed\n");
running = false; /* stop main loop */
break;
}
}
kqueue_free(kq);
close(kefd);
kefd = -1;
return NULL;
}
static void
kextloop_break(void) {
kextloop_running = false;
if (pthread_join(kextloop_thr, NULL) != 0) {
fprintf(stderr, "Failed to join kextloop thread - exiting\n");
exit(EXIT_FAILURE);
}
}
static int
kextloop_spawn(kevent_ctx_t *ctx) {
kqueue_t *kq = NULL;
if ((kefd = kextctl_open()) == -1) {
fprintf(stderr, "kextctl_open() failed: %s (%i)\n",
strerror(errno), errno);
goto errout;
}
/* from here on the kernel blocks execs until we ACK */
kq = kqueue_new();
if (!kq) {
fprintf(stderr, "kqueue_new() failed: %s (%i)\n",
strerror(errno), errno);
goto errout;
}
if (kqueue_add_fd_read(kq, kefd, ctx) == -1) {
fprintf(stderr, "kqueue_add_fd_read(/dev/xnumon) failed: "
"%s (%i)\n", strerror(errno), errno);
goto errout;
}
if (pthread_create(&kextloop_thr, NULL, kextloop_thread, kq) != 0) {
fprintf(stderr, "pthread_create() failed: "
"%s (%i)\n", strerror(errno), errno);
goto errout;
}
return 0;
errout:
if (kq) {
kqueue_free(kq);
}
if (kefd != -1) {
close(kefd);
kefd = -1;
}
return -1;
}
/*
* Construct an absolute path from a possibly relative path and fully resolve
* all symlinks.
*
* If use_cwd is true, use the current working directory for process pid to
* construct the full path of a relative path. If use_cwd is false, fail if
* path is relative.
*
* Caller must free *path, but not *cwd.
*/
static void NONNULL(1,2,3,5)
path_resolve(char **path, const char **cwd, const char *unrpath,
pid_t pid, struct timespec *tv, bool use_cwd) {
if (use_cwd) {
*cwd = procmon_getcwd(pid, tv);
if (!*cwd && (errno == ENOMEM))
ooms++;
} else {
*cwd = NULL;
}
*path = sys_realpath(unrpath, *cwd);
if (!*path && (errno == ENOMEM))
ooms++;
}
/*
* Variant of path_resolve for symlinks. Fully resolves all directory
* components of the resulting path, but keeps the symlink itself unresolved.
*/
static void NONNULL(1,2,3,5)
path_resolve_symlink(char **path, const char **cwd, const char *unrpath,
pid_t pid, struct timespec *tv, bool use_cwd) {
if (use_cwd) {
*cwd = procmon_getcwd(pid, tv);
if (!*cwd && (errno == ENOMEM))
ooms++;
} else {
*cwd = NULL;
}
*path = sys_realdir(unrpath, *cwd);
if (!*path && (errno == ENOMEM))
ooms++;
}
/*
* Called when the auditpipe file descriptor is readable.
*
* XNU BSD syscalls:
* https://github.com/apple/darwin-xnu/blob/master/bsd/kern/syscalls.master
* XNU Mach syscalls:
* https://github.com/apple/darwin-xnu/blob/master/osfmk/mach/syscall_sw.h
*
* Mostly complete workarounds for the following bugs in audit(4):
* 38845422: audit(4): nonsensical path and missing attr for posix_spawn(2)
* 38845784: audit(4): spurious return value for execve(2)
* 39267328: audit(4): target path not resolved for rename(2) [fixed]
* 39623812: audit(4): path not resolved for utimes(2)
* 42783724: audit(4): target path not resolved for link(2) [fixed]
* 43063872: audit(4): port in wrong byte order for ports on IPv6 sockets
*
* Partial workarounds for the following audit(4) bugs:
* 42784847: audit(4): path not resolved for symlink(2) and symlinkat(2)
* 42770257: audit(4): missing destination path tokens for renameat(2)
* 43151662: audit(4): missing destination path tokens for linkat(2)
*
* Only detection, no workaround for the following bugs in audit(4):
* 42946744: audit(4): missing argv and arge for __mac_execve(2)
*
* Neither detection nor workaround for the following bugs in audit(4):
* 40755284: audit(4): processor_set_tasks() cannot be audited
* 43006946: audit(4): no AUE_CONNECT for connect(2) on non-blocking socket
*
* Presence of bugs without workaround can be detected using the test suite.
*/
#define TOKEN_ASSERT(EVENT, TOKEN, COND) \
if (!(COND)) { \
missingtoken++; \
DEBUG(cfg->debug, "missingtoken", \
"event=" EVENT " token=" TOKEN); \
if (cfg->debug) \
auevent_fprint(stderr, &ev); \
break; \
}
static int
auef_readable(UNUSED int fd, void *udata) {
config_t *cfg = (config_t *)udata;
audit_event_t ev;
const char *cwd;
char *path;
const char *cpath;
bool flag;
int rv;
auevent_create(&ev);
rv = auevent_fread(&ev, NULL, cfg->envlevel /* HACK */, auef);
if (rv == -1 || rv == 0) {
if (ev.flags & AEFLAG_ENOMEM)
ooms++;
auevent_destroy(&ev);
return rv;
}
#ifdef DEBUG_AUDITPIPE
auevent_fprint(stderr, &ev);
#endif
/* avoid reacting on our own close invocations */
if (ev.subject.pid == xnumon_pid)
goto out;
switch (ev.type) {
/*
* Events for process monitoring.
*/
case AUE_FORK:
case AUE_VFORK:
TOKEN_ASSERT("fork", "return", ev.return_present);
if (ev.return_value > INT_MAX) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("fork", "subject", ev.subject_present);
procmon_fork(&ev.tv, &ev.subject, ev.return_value);
break;
case AUE_POSIX_SPAWN:
TOKEN_ASSERT("posix_spawn", "return", ev.return_present);
if (ev.return_value) {
/* posix_spawnp spams an event for each directory in
* $PATH with return_value==2 until it finds the actual
* matching executable (10.11.6) */
failedsyscalls++;
break;
}
TOKEN_ASSERT("posix_spawn", "subject", ev.subject_present);
/*
* On at least 10.11.6 and 10.12.6, the following happens:
* path is /dev/console when launchd spawns xpcproxy,
* path is /dev/null when xpcproxy execs the XPC target,
* path is $CWD/dev/ttysNNN when lldb spawns debug subject;
* in all of these cases, no attr token is provided, and there
* is only one path instead of two.
*
* Reported to Apple as radar 38845422 on 2018-03-25.
*
* As a result, whenever no attr is present or path starts in
* /dev, assume a buggy path. First try the path by pid.
* If that fails, employ less reliable ways to work around the
* issue.
*/
path = (char *)(ev.path[1] ? ev.path[1] : ev.path[0]);
if (ev.attr_count == 0 || !path ||
!str_beginswith(path, "/dev/")) {
radar38845422++;
path = sys_pidpath(ev.args[0].present ?
ev.args[0].value : ev.subject.pid);
if (!path) {
if (!ev.execarg) {
radar38845422_fatal++;
DEBUG(cfg->debug,
"radar38845422_fatal",
"path[0]=%s "
"path[1]=%s "
"args[0]=%i "
"pid=%i "
"sys_pidpath(args[0]||pid)=>%s",
ev.path[0],
ev.path[1],
ev.args[0].present
? (int)ev.args[0].value : -1,
ev.subject.pid,
cwd);
break;
}
/* When launchd spawns the xpcproxy exec
* trampoline, path is /dev/console and argv[0]
* is just xpcproxy; hardcode that.
* This allows a malicious binary to be named
* xpcproxy and triggering this kernel bug to
* hide its hash and codesigning status from
* us unless kextlevel >= 1. */
if (!strcmp(ev.execarg[0], "xpcproxy")) {
path = strdup("/usr/libexec/xpcproxy");
} else {
/* As a last resort, use execarg[0] as
* path; note that this is not always
* absolute, can be just the basename;
* also it is forgeable.
* If we are using the kext, the real
* path will be fetched from the kext.
* If not, there will be no way to
* reliably find the corresponding
* image on disk. */
path = strdup(ev.execarg[0]);
}
if (!path)
ooms++;
}
} else {
path = strdup(path);
if (!path)
ooms++;
}
if (!path)
/* got counted above */
break;
if (!ev.args[0].present) {
/* POSIX_SPAWN_SETEXEC */
procmon_exec(&ev.tv,
&ev.subject,
path,
ev.attr_count > 0 ? &ev.attr[0] : NULL,
ev.execarg,
ev.execenv);
ev.execarg = NULL; /* pass ownership to procmon */
ev.execenv = NULL; /* pass ownership to procmon */
break;
}
TOKEN_ASSERT("execve", "args[0]", ev.args[0].present);
procmon_spawn(&ev.tv,
&ev.subject,
ev.args[0].value,
path,
ev.attr_count > 0 ? &ev.attr[0] : NULL,
ev.execarg,
ev.execenv);
ev.execarg = NULL; /* pass ownership to procmon */
ev.execenv = NULL; /* pass ownership to procmon */
break;
case AUE_EXEC:
case AUE_EXECVE:
case AUE_MAC_EXECVE:
TOKEN_ASSERT("execve", "subject", ev.subject_present);
/*
* On at least 10.11.6, audit records for successful execve
* invocations sometimes have a pid as return value, for
* example when being spawned from make, which does not
* indicate failure; only treat negative values as errors.
*
* Reported to Apple as radar 38845784 on 2018-03-25.
*/
if (ev.return_present) {
if (ev.return_value > INT_MAX) {
failedsyscalls++;
break;
} else if (ev.return_value != 0) {
radar38845784++;
}
}
TOKEN_ASSERT("execve", "path", ev.path[0]);
path = (char *)(ev.path[1] ? ev.path[1] : ev.path[0]);
assert(path);
path = strdup(path);
if (!path) {
ooms++;
break;
}
if (ev.type == AUE_MAC_EXECVE && (
!ev.execarg || ((cfg->envlevel > 0) && !ev.execenv))) {
/*
* On at least 10.11.6, audit records for __mac_execve
* are missing their exec arg and exec env tokens.
*
* Reported to Apple as radar 42946744 on 2018-08-05.
*/
radar42946744_fatal++;
DEBUG(cfg->debug,
"radar42946744_fatal",
"path[0]=%s "
"path[1]=%s "
"argv=%i env=%i "
"pid=%i",
ev.path[0],
ev.path[1],
ev.execarg ? 1 : 0,
ev.execenv ? 1 : 0,
ev.subject.pid);
}
procmon_exec(&ev.tv,
&ev.subject,
path,
ev.attr_count > 0 ? &ev.attr[0] : NULL,
ev.execarg,
ev.execenv);
ev.execarg = NULL; /* pass ownership to procmon */
ev.execenv = NULL; /* pass ownership to procmon */
break;
case AUE_EXIT:
TOKEN_ASSERT("exit", "subject", ev.subject_present);
/* exit never fails; audit event not triggered if process got
* terminated in other ways than calling exit() */
procmon_exit(&ev.tv, ev.subject.pid);
break;
case AUE_WAIT4:
TOKEN_ASSERT("wait4", "return", ev.return_present);
if (ev.return_value == 0 || ev.return_value > INT_MAX) {
failedsyscalls++;
break;
}
/* cannot distinguish terminated and stopped processes */
procmon_wait4(&ev.tv, ev.return_value);
break;
case AUE_CHDIR:
case AUE_FCHDIR:
TOKEN_ASSERT("chdir", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("chdir", "subject", ev.subject_present);
TOKEN_ASSERT("chdir", "path", ev.path[0]);
path = (char *)(ev.path[1] ? ev.path[1] : ev.path[0]);
assert(path);
path = strdup(path);
if (!path) {
ooms++;
break;
}
procmon_chdir(&ev.tv, ev.subject.pid, path);
break;
/*
* Events for tracking inter-process access commonly used for
* code injection and other manipulation.
*/
case AUE_TASKFORPID:
if (!LOGEVT_WANT(cfg->events, LOGEVT_HACKMON))
break;
TOKEN_ASSERT("task_for_pid", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("task_for_pid", "subject", ev.subject_present);
TOKEN_ASSERT("task_for_pid", "process|args[2](pid)",
ev.process_present || ev.args[2].present);
if (ev.process_present) {
hackmon_taskforpid(&ev.tv, &ev.subject,
&ev.process, ev.process.pid);
} else {
hackmon_taskforpid(&ev.tv, &ev.subject,
NULL, ev.args[2].value);
}
break;
case AUE_PTRACE:
if (!LOGEVT_WANT(cfg->events, LOGEVT_HACKMON))
break;
TOKEN_ASSERT("ptrace", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("ptrace", "subject", ev.subject_present);
TOKEN_ASSERT("ptrace", "args[1](request)", ev.args[1].present);
if (ev.args[1].value != PT_ATTACHEXC)
break;
TOKEN_ASSERT("ptrace", "process|args[2](pid)",
ev.process_present || ev.args[2].present);
if (ev.process_present) {
hackmon_ptrace(&ev.tv, &ev.subject,
&ev.process, ev.process.pid);
} else {
hackmon_ptrace(&ev.tv, &ev.subject,
NULL, ev.args[2].value);
}
break;
/*
* Events for tracking file modifications.
*/
case AUE_OPEN_W:
case AUE_OPEN_WC:
case AUE_OPEN_WT:
case AUE_OPEN_WTC:
case AUE_OPEN_RW:
case AUE_OPEN_RWC:
case AUE_OPEN_RWT:
case AUE_OPEN_RWTC:
case AUE_OPEN_EXTENDED_W:
case AUE_OPEN_EXTENDED_WC:
case AUE_OPEN_EXTENDED_WT:
case AUE_OPEN_EXTENDED_WTC:
case AUE_OPEN_EXTENDED_RW:
case AUE_OPEN_EXTENDED_RWC:
case AUE_OPEN_EXTENDED_RWT:
case AUE_OPEN_EXTENDED_RWTC:
case AUE_OPENAT_W:
case AUE_OPENAT_WC:
case AUE_OPENAT_WT:
case AUE_OPENAT_WTC:
case AUE_OPENAT_RW:
case AUE_OPENAT_RWC:
case AUE_OPENAT_RWT:
case AUE_OPENAT_RWTC:
case AUE_OPENBYID_W:
case AUE_OPENBYID_WT:
case AUE_OPENBYID_RW:
case AUE_OPENBYID_RWT:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
TOKEN_ASSERT("open(w)", "return", ev.return_present);
if (ev.return_value > INT_MAX) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("open(w)", "subject", ev.subject_present);
#if 0
TOKEN_ASSERT("open(w)", "arg[2](flags)", ev.args[2].present);
TOKEN_ASSERT("open(w)", "arg[3](mode)", ev.args[3].present);
#endif
TOKEN_ASSERT("open(2)", "path[0]", ev.path[0]);
/* sometimes one, sometimes two path tokens, unsure if bug */
path = (char *)(ev.path[1] ? ev.path[1] : ev.path[0]);
assert(path);
procmon_file_open(&ev.subject, ev.return_value, path, &ev.tv);
break;
case AUE_CLOSE:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON|LOGEVT_SOCKMON))
break;
TOKEN_ASSERT("close", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("close", "subject", ev.subject_present);
TOKEN_ASSERT("close", "arg[2](fd)", ev.args[2].present);
procmon_fd_close(ev.subject.pid, ev.args[2].value);
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
if (!ev.path[0]) {
/* closed file descriptor does not point to vnode */
break;
}
path = (char *)(ev.path[1] ? ev.path[1] : ev.path[0]);
assert(path);
path = strdup(path);
if (!path) {
ooms++;
break;
}
filemon_touched(&ev.tv, &ev.subject, path);
break;
case AUE_UTIMES:
case AUE_FUTIMES:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
TOKEN_ASSERT("utimes", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("utimes", "subject", ev.subject_present);
/*
* On at least 10.11.6, records include only an unresolved
* path.
*
* Reported to Apple as radar 39623812 on 2018-04-21.
*/
if (ev.path[1]) {
/* two path tokens */
path = strdup(ev.path[1]);
if (!path)
ooms++;
} else if (ev.path[0]) {
/* one path token, assume unresolved if no attr */
if (ev.attr_count > 0) {
path = strdup(ev.path[0]);
if (!path)
ooms++;
} else {
radar39623812++;
path_resolve(&path, &cwd, ev.path[0],
ev.subject.pid, &ev.tv, true);
if (!path && (errno != ENOMEM)) {
radar39623812_fatal++;
DEBUG(cfg->debug, "radar39623812_fatal",
"path[0]=%s pid=%i "
"cwd(pid)=>%s",
ev.path[0], ev.subject.pid, cwd);
}
}
} else {
path = NULL;
missingtoken++;
DEBUG(cfg->debug, "missingtoken",
"event=utimes token=path");
if (cfg->debug)
auevent_fprint(stderr, &ev);
}
if (!path)
/* counted above */
break;
filemon_touched(&ev.tv, &ev.subject, path);
break;
case AUE_RENAMEAT:
case AUE_LINKAT:
case AUE_CLONEFILEAT:
case AUE_FCLONEFILEAT:
flag = false; /* dont resolve relative to cwd on path bugs */
goto rename_et_al;
case AUE_RENAME:
case AUE_LINK:
case AUE_COPYFILE: /* copyfile(2) not copyfile(3) */
flag = true; /* resolve relative to cwd on path bugs */
rename_et_al:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
TOKEN_ASSERT("rename|link|clonefile|copyfile",
"return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("rename|link|clonefile|copyfile",
"subject", ev.subject_present);
/*
* Before 10.14.3/2019-001, AUE_RENAME and AUE_LINK records
* include only an unresolved target path.
*
* Reported to Apple as radar 39267328 on 2018-04-08 and
* radar 42783724 on 2018-07-31 respectively. Fix published by
* Apple on 2019-01-22.
*/
if (ev.path[3]) {
/* four path tokens, as expected */
path = strdup(ev.path[3]);
if (!path)
ooms++;
} else if (ev.path[2] && !ev.path[3]) {
/* three path tokens, assume third unresolved dpath */
switch (ev.type) {
case AUE_RENAME:
radar39267328++;
break;
case AUE_LINK:
radar42783724++;
break;
default:
missingtoken++;
DEBUG(cfg->debug, "missingtoken",
"event=rename|link|clonefile|copyfile "
"token=path");
if (cfg->debug)
auevent_fprint(stderr, &ev);
break;
}
path_resolve(&path, &cwd, ev.path[2],
ev.subject.pid, &ev.tv, flag);
if (!path && (errno != ENOMEM)) {
switch (ev.type) {
case AUE_RENAME:
radar39267328_fatal++;
DEBUG(cfg->debug,
"radar39267328_fatal",
"path[2]=%s pid=%i "
"getcwd(pid)=>%s",
ev.path[2], ev.subject.pid, cwd);
break;
case AUE_LINK:
radar42783724_fatal++;
DEBUG(cfg->debug,
"radar42783724_fatal",
"path[2]=%s pid=%i "
"getcwd(pid)=>%s",
ev.path[2], ev.subject.pid, cwd);
break;
}
/* others already got a "missingtoken" above */
}
} else {
/* less than three path tokens */
path = NULL;
/*
* AUE_RENAMEAT and AUE_LINKAT records sometimes have
* only one or two path tokens instead of four.
*
* Reported to Apple as radar 42770257 and 43151662 on
* 2018-07-31 and 2018-08-10 respectively.
*/
switch (ev.type) {
case AUE_RENAMEAT:
radar42770257_fatal++;
DEBUG(cfg->debug, "radar42770257_fatal",
"event=renameat token=path");
break;
case AUE_LINKAT:
radar43151662_fatal++;
DEBUG(cfg->debug, "radar43151662_fatal",
"event=linkat token=path");
break;
default:
missingtoken++;
DEBUG(cfg->debug, "missingtoken",
"event=rename|link|clonefile|copyfile "
"token=path");
if (cfg->debug)
auevent_fprint(stderr, &ev);
break;
}
}
if (!path)
/* counted above */
break;
filemon_touched(&ev.tv, &ev.subject, path);
break;
case AUE_SYMLINK:
case AUE_SYMLINKAT:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
TOKEN_ASSERT("symlink", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("symlink", "subject", ev.subject_present);
/*
* On at least 10.11.6, AUE_SYMLINK and AUE_SYMLINKAT records
* include only an unresolved target path.
*
* Reported to Apple as radar 42784847 on 2018-07-31.
*/
if (ev.path[1]) {
path = strdup(ev.path[1]);
if (!path)
ooms++;
} else if (ev.path[0] && !ev.path[1]) {
/* only an unresolved target path token */
radar42784847++;
path_resolve_symlink(&path, &cwd, ev.path[0],
ev.subject.pid, &ev.tv,
(ev.type == AUE_SYMLINK));
if (!path && (errno != ENOMEM)) {
radar42784847_fatal++;
DEBUG(cfg->debug,
"radar42784847_fatal",
"path[0]=%s pid=%i "
"getcwd(pid)=>%s",
ev.path[0], ev.subject.pid, cwd);
}
} else {
path = NULL;
missingtoken++;
DEBUG(cfg->debug, "missingtoken",
"event=symlink token=path");
if (cfg->debug)
auevent_fprint(stderr, &ev);
}
if (!path)
/* counted above */
break;
filemon_symlink(&ev.tv, &ev.subject, path);
break;
case AUE_UNLINK:
case AUE_UNLINKAT:
if (!LOGEVT_WANT(cfg->events, LOGEVT_FILEMON))
break;
TOKEN_ASSERT("unlink", "return", ev.return_present);
if (ev.return_value) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("unlink", "subject", ev.subject_present);
if (ev.path[1]) {
/* two path tokens */
cpath = ev.path[1];
#if 0
} else if (ev.path[0]) {
/* one path token, assume unresolved if no attr */
if (ev.attr_count > 0) {
path = strdup(ev.path[0]);
if (!path)
ooms++;
} else {
radarXXX++;
path_resolve_symlink(&path, &cwd, ev.path[0],
ev.subject.pid, &ev.tv,
(ev.type == AUE_UNLINK));
if (!path && (errno != ENOMEM)) {
radarXXX_fatal++;
DEBUG(cfg->debug, "radarXXX_fatal",
"path[0]=%s pid=%i "
"cwd(pid)=>%s",
ev.path[0], ev.subject.pid, cwd);
}
}
// XXX free path after call to unlink!
#endif
} else {
cpath = NULL;
missingtoken++;
DEBUG(cfg->debug, "missingtoken",
"event=unlink token=path");
if (cfg->debug)
auevent_fprint(stderr, &ev);
}
if (!cpath)
/* counted above */
break;
filemon_unlink(cpath, ev.attr_count > 0 ? &ev.attr[0] : NULL);
break;
/*
* Events for socket tracking.
*/
case AUE_SOCKET:
if (!LOGEVT_WANT(cfg->events, LOGEVT_SOCKMON))
break;
TOKEN_ASSERT("socket", "return", ev.return_present);
if (ev.return_value > INT_MAX) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("socket", "subject", ev.subject_present);
TOKEN_ASSERT("socket", "arg[1](domain)", ev.args[1].present);
TOKEN_ASSERT("socket", "arg[2](type)", ev.args[2].present);
TOKEN_ASSERT("socket", "arg[3](protocol)", ev.args[3].present);
sockmon_socket(&ev.tv, &ev.subject, ev.return_value,
auevent_sock_domain(ev.args[1].value),
auevent_sock_type(ev.args[2].value),
ev.args[3].value);
break;
case AUE_BIND:
if (!LOGEVT_WANT(cfg->events, LOGEVT_SOCKMON))
break;
TOKEN_ASSERT("bind", "return", ev.return_present);
if (ev.return_value != 0) {
failedsyscalls++;
break;
}
if (!ev.sockinet_present)
/* skip unix socket */
break;
TOKEN_ASSERT("bind", "subject", ev.subject_present);
TOKEN_ASSERT("bind", "arg[1](fd)", ev.args[1].present);
sockmon_bind(&ev.tv, &ev.subject, ev.args[1].value,
&ev.sockinet_addr, ev.sockinet_port);
break;
case AUE_LISTEN:
if (!LOGEVT_WANT(cfg->events,
LOGEVT_FLAG(LOGEVT_SOCKET_LISTEN)))
break;
TOKEN_ASSERT("listen", "return", ev.return_present);
if (ev.return_value != 0) {
failedsyscalls++;
break;
}
TOKEN_ASSERT("listen", "subject", ev.subject_present);
TOKEN_ASSERT("listen", "arg[1](fd)", ev.args[1].present);
sockmon_listen(&ev.tv, &ev.subject, ev.args[1].value);
break;
case AUE_ACCEPT:
if (!LOGEVT_WANT(cfg->events,
LOGEVT_FLAG(LOGEVT_SOCKET_ACCEPT)))
break;
TOKEN_ASSERT("accept", "return", ev.return_present);
if (ev.return_value > INT_MAX) {
failedsyscalls++;
break;
}
if (!ev.sockinet_present)
/* skip unix socket */
break;
TOKEN_ASSERT("accept", "subject", ev.subject_present);
TOKEN_ASSERT("accept", "arg[1](fd)", ev.args[1].present);
sockmon_accept(&ev.tv, &ev.subject, ev.args[1].value,
&ev.sockinet_addr, ev.sockinet_port);
break;
case AUE_CONNECT:
if (!LOGEVT_WANT(cfg->events,
LOGEVT_FLAG(LOGEVT_SOCKET_CONNECT)))
break;
/* While it would be interesting to see failed connects,
* XNU does not seem to provide audit(4) records for them. */
TOKEN_ASSERT("connect", "return", ev.return_present);
if (ev.return_value != 0) {
failedsyscalls++;
break;
}
if (!ev.sockinet_present)
/* unix socket */
break;
TOKEN_ASSERT("connect", "subject", ev.subject_present);
TOKEN_ASSERT("connect", "arg[1](fd)", ev.args[1].present);
sockmon_connect(&ev.tv, &ev.subject, ev.args[1].value,
&ev.sockinet_addr, ev.sockinet_port);
break;
/*
* Unhandled events.
*/
default:
/*
* Some event types seem to be logged regardless of the class
* mask settings. However, their volume seems to be low, so
* far only userspace events have been seen (10.11.6), so we
* just ignore them here instead of filtering on each event.
*/
#ifdef DEBUG_AUDITPIPE
fprintf(stderr, "Unhandled event type=%u\n", ev.type);
#endif
aueunknowns++;
break;
}
out:
auevent_destroy(&ev); /* free all allocated members not NULLed above */
return 0;
}
#undef TOKEN_ASSERT
/*
* Handles SIGTERM, SIGQUIT and SIGINT.
*/
static int
sigquit_arrived(UNUSED int sig, UNUSED void *udata) {
running = false;
fprintf(stderr, "Shutting down, draining queues...\n");
return -1; /* stop processing more events */
}