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-rw-r--r--trace/preload.c80
-rw-r--r--trace/trace.c222
2 files changed, 302 insertions, 0 deletions
diff --git a/trace/preload.c b/trace/preload.c
new file mode 100644
index 0000000..99dd906
--- /dev/null
+++ b/trace/preload.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define _GNU_SOURCE
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <dlfcn.h>
+
+#include "../preload.h"
+
+#define ERROR(fmt, ...) do { \
+ fprintf(stderr,"perload-jail: "fmt, ## __VA_ARGS__); \
+ } while (0)
+
+static main_t __main__;
+
+static int __preload_main__(int argc, char **argv, char **envp)
+{
+ unsetenv("LD_PRELOAD");
+ ptrace(PTRACE_TRACEME);
+ kill(getpid(), SIGSTOP);
+
+ return (*__main__)(argc, argv, envp);
+}
+
+int __libc_start_main(main_t main,
+ int argc,
+ char **argv,
+ ElfW(auxv_t) *auxvec,
+ __typeof (main) init,
+ void (*fini) (void),
+ void (*rtld_fini) (void),
+ void *stack_end)
+{
+ start_main_t __start_main__;
+
+ __start_main__ = dlsym(RTLD_NEXT, "__libc_start_main");
+ if (!__start_main__)
+ ERROR("failed to find __libc_start_main %s\n", dlerror());
+
+ __main__ = main;
+
+ return (*__start_main__)(__preload_main__, argc, argv, auxvec,
+ init, fini, rtld_fini, stack_end);
+}
+
+void __uClibc_main(main_t main,
+ int argc,
+ char **argv,
+ void (*app_init)(void),
+ void (*app_fini)(void),
+ void (*rtld_fini)(void),
+ void *stack_end attribute_unused)
+{
+ uClibc_main __start_main__;
+
+ __start_main__ = dlsym(RTLD_NEXT, "__uClibc_main");
+ if (!__start_main__)
+ ERROR("failed to find __uClibc_main %s\n", dlerror());
+
+ __main__ = main;
+
+ return (*__start_main__)(__preload_main__, argc, argv,
+ app_init, app_fini, rtld_fini, stack_end);
+}
diff --git a/trace/trace.c b/trace/trace.c
new file mode 100644
index 0000000..c6f32d7
--- /dev/null
+++ b/trace/trace.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define _GNU_SOURCE
+#include <stddef.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <syslog.h>
+
+#include <libubox/uloop.h>
+#include <libubox/blobmsg.h>
+#include <libubox/blobmsg_json.h>
+
+#include "../syscall-names.h"
+
+#define _offsetof(a, b) __builtin_offsetof(a,b)
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#ifdef __amd64__
+#define reg_syscall_nr _offsetof(struct user, regs.orig_rax)
+#elif defined(__i386__)
+#define reg_syscall_nr _offsetof(struct user, regs.orig_eax)
+#elif defined(__mips)
+# ifndef EF_REG2
+# define EF_REG2 8
+# endif
+#define reg_syscall_nr (EF_REG2 / 4)
+#else
+#error tracing is not supported on this architecture
+#endif
+
+#define INFO(fmt, ...) do { \
+ fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
+} while (0)
+
+#define ERROR(fmt, ...) do { \
+ syslog(0, "utrace: "fmt, ## __VA_ARGS__); \
+ fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
+} while (0)
+
+static struct uloop_process tracer;
+static int *syscall_count;
+static struct blob_buf b;
+static int syscall_max;
+static int in_syscall;
+static int debug;
+
+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)) {
+ syscall_count[i] = val;
+ return;
+ }
+}
+
+static void print_syscalls(int policy, const char *json)
+{
+ void *c;
+ int i;
+
+ set_syscall("rt_sigaction", 1);
+ set_syscall("sigreturn", 1);
+ set_syscall("rt_sigreturn", 1);
+ set_syscall("exit_group", 1);
+ set_syscall("exit", 1);
+
+ blob_buf_init(&b, 0);
+ c = blobmsg_open_array(&b, "whitelist");
+
+ for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
+ if (!syscall_count[i])
+ continue;
+ if (syscall_names[i]) {
+ if (debug)
+ printf("syscall %d (%s) was called %d times\n",
+ i, syscall_names[i], syscall_count[i]);
+ blobmsg_add_string(&b, NULL, syscall_names[i]);
+ } else {
+ ERROR("no name found for syscall(%d)\n", i);
+ }
+ }
+ blobmsg_close_array(&b, c);
+ blobmsg_add_u32(&b, "policy", policy);
+ if (json) {
+ FILE *fp = fopen(json, "w");
+ if (fp) {
+ fprintf(fp, "%s", blobmsg_format_json_indent(b.head, true, 0));
+ fclose(fp);
+ INFO("saving syscall trace to %s\n", json);
+ } else {
+ ERROR("failed to open %s\n", json);
+ }
+ } else {
+ printf("%s\n",
+ blobmsg_format_json_indent(b.head, true, 0));
+ }
+
+}
+
+static void tracer_cb(struct uloop_process *c, int ret)
+{
+ if (WIFSTOPPED(ret) && WSTOPSIG(ret) & 0x80) {
+ if (!in_syscall) {
+ int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
+
+ if (syscall < syscall_max) {
+ syscall_count[syscall]++;
+ if (debug)
+ fprintf(stderr, "%s()\n", syscall_names[syscall]);
+ } else if (debug) {
+ fprintf(stderr, "syscal(%d)\n", syscall);
+ }
+ }
+ in_syscall = !in_syscall;
+ } else if (WIFEXITED(ret)) {
+ uloop_end();
+ return;
+ }
+ ptrace(PTRACE_SYSCALL, c->pid, 0, 0);
+ uloop_process_add(&tracer);
+}
+
+int main(int argc, char **argv, char **envp)
+{
+ char *json = NULL;
+ int status, ch, policy = EPERM;
+ pid_t child;
+
+ while ((ch = getopt(argc, argv, "f:p:")) != -1) {
+ switch (ch) {
+ case 'f':
+ json = optarg;
+ break;
+ case 'p':
+ policy = atoi(optarg);
+ break;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ if (!argc)
+ return -1;
+
+ if (getenv("TRACE_DEBUG"))
+ debug = 1;
+ unsetenv("TRACE_DEBUG");
+
+ child = fork();
+
+ if (child == 0) {
+ char **_argv = calloc(argc + 1, sizeof(char *));
+ char **_envp;
+ char preload[] = "LD_PRELOAD=/lib/libpreload-trace.so";
+ int envc = 1;
+ int ret;
+
+ memcpy(_argv, argv, argc * sizeof(char *));
+
+ while (envp[envc++])
+ ;
+
+ _envp = calloc(envc, sizeof(char *));
+ memcpy(&_envp[1], _envp, envc * sizeof(char *));
+ *envp = preload;
+
+ ret = execve(_argv[0], _argv, envp);
+ ERROR("failed to exec %s: %s\n", _argv[0], strerror(errno));
+ return ret;
+ }
+
+ if (child < 0)
+ return -1;
+
+ syscall_max = ARRAY_SIZE(syscall_names);
+ syscall_count = calloc(syscall_max, sizeof(int));
+ waitpid(child, &status, 0);
+ if (!WIFSTOPPED(status)) {
+ ERROR("failed to start %s\n", *argv);
+ return -1;
+ }
+
+ ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD);
+ ptrace(PTRACE_SYSCALL, child, 0, 0);
+
+ uloop_init();
+ tracer.pid = child;
+ tracer.cb = tracer_cb;
+ uloop_process_add(&tracer);
+ uloop_run();
+ uloop_done();
+
+ if (!json)
+ asprintf(&json, "/tmp/%s.%u.json", basename(*argv), child);
+
+ print_syscalls(policy, json);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 02:47:15 +0100