#include <errno.h>
#include <string.h>
#include <syslog.h>
-#include <err.h>
+#include <limits.h>
#ifndef PTRACE_EVENT_STOP
/* PTRACE_EVENT_STOP is defined in linux/ptrace.h, but this header
#define PTRACE_EVENT_STOP 128
#endif
+#include <libubox/ulog.h>
#include <libubox/uloop.h>
#include <libubox/blobmsg.h>
#include <libubox/blobmsg_json.h>
SECCOMP_TRACE,
} mode = UTRACE;
-#define PROC_NAME(mode) (mode == UTRACE ? "utrace" : "seccomp-trace")
-
-#define INFO(fmt, ...) do { \
- fprintf(stderr, "%s: "fmt, PROC_NAME(mode), ## __VA_ARGS__); \
-} while (0)
-
-#define ERROR(fmt, ...) do { \
- syslog(LOG_ERR, "%s: "fmt, PROC_NAME(mode), ## __VA_ARGS__); \
- fprintf(stderr, "%s: "fmt, PROC_NAME(mode), ## __VA_ARGS__); \
-} while (0)
-
-#define LOGERR(fmt, ...) do { \
- syslog(LOG_ERR, "%s: "fmt, PROC_NAME(mode), ## __VA_ARGS__); \
-} while (0)
-
struct tracee {
struct uloop_process proc;
int in_syscall;
};
static struct tracee tracer;
-static int *syscall_count;
+static int syscall_count[SYSCALL_COUNT];
static int violation_count;
static struct blob_buf b;
-static int syscall_max;
static int debug;
char *json = NULL;
int ptrace_restart;
-static int max_syscall = ARRAY_SIZE(syscall_names);
-
static void set_syscall(const char *name, int val)
{
int i;
- for (i = 0; i < max_syscall; i++)
- if (syscall_names[i] && !strcmp(syscall_names[i], name)) {
+ for (i = 0; i < SYSCALL_COUNT; i++) {
+ int sc = syscall_index_to_number(i);
+ if (syscall_name(sc) && !strcmp(syscall_name(sc), name)) {
syscall_count[i] = val;
return;
}
+ }
}
struct syscall {
set_syscall("exit", 1);
}
- struct syscall sorted[ARRAY_SIZE(syscall_names)];
+ struct syscall sorted[SYSCALL_COUNT];
- for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
- sorted[i].syscall = i;
+ for (i = 0; i < SYSCALL_COUNT; i++) {
+ sorted[i].syscall = syscall_index_to_number(i);
sorted[i].count = syscall_count[i];
}
- qsort(sorted, ARRAY_SIZE(syscall_names), sizeof(sorted[0]), cmp_count);
+ qsort(sorted, SYSCALL_COUNT, sizeof(sorted[0]), cmp_count);
blob_buf_init(&b, 0);
c = blobmsg_open_array(&b, "whitelist");
- for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
+ for (i = 0; i < SYSCALL_COUNT; i++) {
int sc = sorted[i].syscall;
if (!sorted[i].count)
break;
- if (syscall_names[sc]) {
+ if (syscall_name(sc)) {
if (debug)
printf("syscall %d (%s) was called %d times\n",
- sc, syscall_names[sc], sorted[i].count);
- blobmsg_add_string(&b, NULL, syscall_names[sc]);
+ sc, syscall_name(sc), sorted[i].count);
+ blobmsg_add_string(&b, NULL, syscall_name(sc));
} else {
- ERROR("no name found for syscall(%d)\n", sc);
+ ULOG_ERR("no name found for syscall(%d)\n", sc);
}
}
blobmsg_close_array(&b, c);
if (fp) {
fprintf(fp, "%s", blobmsg_format_json_indent(b.head, true, 0));
fclose(fp);
- INFO("saving syscall trace to %s\n", json);
+ ULOG_INFO("saving syscall trace to %s\n", json);
} else {
- ERROR("failed to open %s\n", json);
+ ULOG_ERR("failed to open %s\n", json);
}
} else {
printf("%s\n",
if (violation_count < INT_MAX)
violation_count++;
- if (syscall < ARRAY_SIZE(syscall_names)) {
- syscall_count[syscall]++;
- LOGERR("%s[%u] tried to call non-whitelisted syscall: %s (see %s)\n",
- buf, pid, syscall_names[syscall], json);
+ int i = syscall_index(syscall);
+ if (i >= 0) {
+ syscall_count[i]++;
+ ULOG_ERR("%s[%u] tried to call non-whitelisted syscall: %s (see %s)\n",
+ buf, pid, syscall_name(syscall), json);
} else {
- LOGERR("%s[%u] tried to call non-whitelisted syscall: %d (see %s)\n",
- buf, pid, syscall, json);
+ ULOG_ERR("%s[%u] tried to call non-whitelisted syscall: %d (see %s)\n",
+ buf, pid, syscall, json);
}
}
if (WSTOPSIG(ret) & 0x80) {
if (!tracee->in_syscall) {
int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
-
- if (syscall < syscall_max) {
- syscall_count[syscall]++;
+ int i = syscall_index(syscall);
+ if (i >= 0) {
+ syscall_count[i]++;
if (debug)
- fprintf(stderr, "%s()\n", syscall_names[syscall]);
+ fprintf(stderr, "%s()\n", syscall_name(syscall));
} else if (debug) {
fprintf(stderr, "syscal(%d)\n", syscall);
}
uloop_process_add(c);
}
+static void sigterm_handler(int signum)
+{
+ /* When we receive SIGTERM, we forward it to the tracee. After
+ * the tracee exits, trace_cb() will be called and make us
+ * exit too. */
+ kill(tracer.proc.pid, SIGTERM);
+}
+
+
int main(int argc, char **argv, char **envp)
{
int status, ch, policy = EPERM;
case SECCOMP_TRACE:
preload = "/lib/libpreload-seccomp.so";
newenv = 2;
- asprintf(&_envp[1], "SECCOMP_FILE=%s", json ? json : "");
+ if (asprintf(&_envp[1], "SECCOMP_FILE=%s", json ? json : "") < 0)
+ ULOG_ERR("failed to allocate SECCOMP_FILE env: %m\n");
+
kill(getpid(), SIGSTOP);
break;
}
- asprintf(&_envp[0], "LD_PRELOAD=%s%s%s", preload,
- old_preload ? ":" : "",
- old_preload ? old_preload : "");
+ if (asprintf(&_envp[0], "LD_PRELOAD=%s%s%s", preload,
+ old_preload ? ":" : "",
+ old_preload ? old_preload : "") < 0)
+ ULOG_ERR("failed to allocate LD_PRELOAD env: %m\n");
+
memcpy(&_envp[newenv], envp, envc * sizeof(char *));
ret = execve(_argv[0], _argv, _envp);
- ERROR("failed to exec %s: %s\n", _argv[0], strerror(errno));
+ ULOG_ERR("failed to exec %s: %m\n", _argv[0]);
free(_argv);
free(_envp);
if (child < 0)
return -1;
- syscall_max = ARRAY_SIZE(syscall_names);
- syscall_count = calloc(syscall_max, sizeof(int));
waitpid(child, &status, WUNTRACED);
if (!WIFSTOPPED(status)) {
- ERROR("failed to start %s\n", *argv);
+ ULOG_ERR("failed to start %s\n", *argv);
return -1;
}
+ /* Initialize uloop to catch all ptrace stops from now on. */
+ uloop_init();
+
int ptrace_options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACECLONE;
switch (mode) {
case UTRACE:
ptrace_restart = PTRACE_CONT;
break;
}
- if (ptrace(PTRACE_SEIZE, child, 0, ptrace_options) == -1)
- err(1, "PTRACE_SEIZE");
- if (ptrace(ptrace_restart, child, 0, SIGCONT) == -1)
- err(1, "ptrace restart");
+ if (ptrace(PTRACE_SEIZE, child, 0, ptrace_options) == -1) {
+ ULOG_ERR("PTRACE_SEIZE: %m\n");
+ return -1;
+ }
+ if (ptrace(ptrace_restart, child, 0, SIGCONT) == -1) {
+ ULOG_ERR("ptrace_restart: %m\n");
+ return -1;
+ }
- uloop_init();
tracer.proc.pid = child;
tracer.proc.cb = tracer_cb;
uloop_process_add(&tracer.proc);
+ signal(SIGTERM, sigterm_handler); /* Override uloop's SIGTERM handler */
uloop_run();
uloop_done();
case UTRACE:
if (!json)
if (asprintf(&json, "/tmp/%s.%u.json", basename(*argv), child) < 0)
- ERROR("failed to allocate output path: %s\n", strerror(errno));
+ ULOG_ERR("failed to allocate output path: %m\n");
break;
case SECCOMP_TRACE:
if (!violation_count)
return 0;
- asprintf(&json, "/tmp/%s.%u.violations.json", basename(*argv), child);
+ if (asprintf(&json, "/tmp/%s.%u.violations.json", basename(*argv), child) < 0)
+ ULOG_ERR("failed to allocate violations output path: %m\n");
break;
}
print_syscalls(policy, json);