logwrapper: split into liblogwrap and the executable itself (113bd47d) · Commits · e / os / android_system_core

logwrapper/Android.mk

+28 −1

Original line number	Diff line number	Diff line
		LOCAL_PATH:= $(call my-dir)

		include $(CLEAR_VARS)

		# ========================================================
		# Static library
		# ========================================================
		include $(CLEAR_VARS)
		LOCAL_MODULE := liblogwrap
		LOCAL_SRC_FILES := logwrap.c
		LOCAL_SHARED_LIBRARIES := libcutils liblog
		LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
		LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
		include $(BUILD_STATIC_LIBRARY)

		# ========================================================
		# Shared library
		# ========================================================
		include $(CLEAR_VARS)
		LOCAL_MODULE := liblogwrap
		LOCAL_SHARED_LIBRARIES := libcutils liblog
		LOCAL_WHOLE_STATIC_LIBRARIES := liblogwrap
		LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
		LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
		include $(BUILD_SHARED_LIBRARY)

		# ========================================================
		# Executable
		# ========================================================
		include $(CLEAR_VARS)
		LOCAL_SRC_FILES:= logwrapper.c
		LOCAL_MODULE := logwrapper
		LOCAL_STATIC_LIBRARIES := liblog
		LOCAL_STATIC_LIBRARIES := liblog liblogwrap
		include $(BUILD_EXECUTABLE)

logwrapper/include/logwrap/logwrap.h

0 → 100644

+27 −0

Original line number	Diff line number	Diff line
		/* system/core/include/logwrap/logwrap.h
		*
		* Copyright 2013, The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#ifndef __LIBS_LOGWRAP_H
		#define __LIBS_LOGWRAP_H

		__BEGIN_DECLS

		int logwrap(int argc, char* argv[], int *chld_sts);

		__END_DECLS

		#endif /* __LIBS_LOGWRAP_H */

logwrapper/logwrap.c

0 → 100644

+161 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2008 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include <string.h>
		#include <sys/types.h>
		#include <sys/wait.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <unistd.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <libgen.h>

		#include <logwrap/logwrap.h>
		#include "private/android_filesystem_config.h"
		#include "cutils/log.h"

		static int fatal(const char *msg) {
		fprintf(stderr, "%s", msg);
		ALOG(LOG_ERROR, "logwrapper", "%s", msg);
		return -1;
		}

		void parent(const char tag, int parent_read, int chld_sts) {
		int status;
		char buffer[4096];

		int a = 0; // start index of unprocessed data
		int b = 0; // end index of unprocessed data
		int sz;

		char *btag = basename(tag);
		if (!btag) btag = (char*) tag;

		while ((sz = read(parent_read, &buffer[b], sizeof(buffer) - 1 - b)) > 0) {

		sz += b;
		// Log one line at a time
		for (b = 0; b < sz; b++) {
		if (buffer[b] == '\r') {
		buffer[b] = '\0';
		} else if (buffer[b] == '\n') {
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		a = b + 1;
		}
		}

		if (a == 0 && b == sizeof(buffer) - 1) {
		// buffer is full, flush
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		b = 0;
		} else if (a != b) {
		// Keep left-overs
		b -= a;
		memmove(buffer, &buffer[a], b);
		a = 0;
		} else {
		a = 0;
		b = 0;
		}

		}
		// Flush remaining data
		if (a != b) {
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		}

		if (wait(&status) != -1) { // Wait for child
		if (WIFEXITED(status) && WEXITSTATUS(status))
		ALOG(LOG_INFO, "logwrapper", "%s terminated by exit(%d)", tag,
		WEXITSTATUS(status));
		else if (WIFSIGNALED(status))
		ALOG(LOG_INFO, "logwrapper", "%s terminated by signal %d", tag,
		WTERMSIG(status));
		else if (WIFSTOPPED(status))
		ALOG(LOG_INFO, "logwrapper", "%s stopped by signal %d", tag,
		WSTOPSIG(status));
		if (chld_sts != NULL)
		*chld_sts = status;
		} else
		ALOG(LOG_INFO, "logwrapper", "%s wait() failed: %s (%d)", tag,
		strerror(errno), errno);
		}

		void child(int argc, char* argv[]) {
		// create null terminated argv_child array
		char* argv_child[argc + 1];
		memcpy(argv_child, argv, argc * sizeof(char *));
		argv_child[argc] = NULL;

		if (execvp(argv_child[0], argv_child)) {
		ALOG(LOG_ERROR, "logwrapper",
		"executing %s failed: %s\n", argv_child[0], strerror(errno));
		exit(-1);
		}
		}

		int logwrap(int argc, char* argv[], int *chld_sts) {
		pid_t pid;

		int parent_ptty;
		int child_ptty;
		char *child_devname = NULL;

		/* Use ptty instead of socketpair so that STDOUT is not buffered */
		parent_ptty = open("/dev/ptmx", O_RDWR);
		if (parent_ptty < 0) {
		return fatal("Cannot create parent ptty\n");
		}

		if (grantpt(parent_ptty) \|\| unlockpt(parent_ptty) \|\|
		((child_devname = (char*)ptsname(parent_ptty)) == 0)) {
		return fatal("Problem with /dev/ptmx\n");
		}

		pid = fork();
		if (pid < 0) {
		close(parent_ptty);
		return fatal("Failed to fork\n");
		} else if (pid == 0) {
		child_ptty = open(child_devname, O_RDWR);
		close(parent_ptty);
		if (child_ptty < 0) {
		return fatal("Problem with child ptty\n");
		}

		// redirect stdout and stderr
		dup2(child_ptty, 1);
		dup2(child_ptty, 2);
		close(child_ptty);

		child(argc - 1, &argv[1]);

		} else {
		// switch user and group to "log"
		// this may fail if we are not root,
		// but in that case switching user/group is unnecessary
		setgid(AID_LOG);
		setuid(AID_LOG);

		parent(argv[1], parent_ptty, chld_sts);
		}

		return 0;
		}

logwrapper/logwrapper.c

+14 −125

Original line number	Diff line number	Diff line
		@@ -14,17 +14,12 @@
		* limitations under the License.
		*/

		#include <string.h>
		#include <sys/types.h>
		#include <sys/wait.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <unistd.h>
		#include <errno.h>
		#include <fcntl.h>
		#include <libgen.h>
		#include <sys/wait.h>

		#include <logwrap/logwrap.h>

		#include "private/android_filesystem_config.h"
		#include "cutils/log.h"

		void fatal(const char *msg) {
		@@ -45,90 +40,10 @@ void usage() {
		" fault address is set to the status of wait()\n");
		}

		void parent(const char *tag, int seg_fault_on_exit, int parent_read) {
		int status;
		char buffer[4096];

		int a = 0; // start index of unprocessed data
		int b = 0; // end index of unprocessed data
		int sz;

		char *btag = basename(tag);
		if (!btag) btag = (char*) tag;

		while ((sz = read(parent_read, &buffer[b], sizeof(buffer) - 1 - b)) > 0) {

		sz += b;
		// Log one line at a time
		for (b = 0; b < sz; b++) {
		if (buffer[b] == '\r') {
		buffer[b] = '\0';
		} else if (buffer[b] == '\n') {
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		a = b + 1;
		}
		}

		if (a == 0 && b == sizeof(buffer) - 1) {
		// buffer is full, flush
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		b = 0;
		} else if (a != b) {
		// Keep left-overs
		b -= a;
		memmove(buffer, &buffer[a], b);
		a = 0;
		} else {
		a = 0;
		b = 0;
		}

		}
		// Flush remaining data
		if (a != b) {
		buffer[b] = '\0';
		ALOG(LOG_INFO, btag, "%s", &buffer[a]);
		}
		status = 0xAAAA;
		if (wait(&status) != -1) { // Wait for child
		if (WIFEXITED(status) && WEXITSTATUS(status))
		ALOG(LOG_INFO, "logwrapper", "%s terminated by exit(%d)", tag,
		WEXITSTATUS(status));
		else if (WIFSIGNALED(status))
		ALOG(LOG_INFO, "logwrapper", "%s terminated by signal %d", tag,
		WTERMSIG(status));
		else if (WIFSTOPPED(status))
		ALOG(LOG_INFO, "logwrapper", "%s stopped by signal %d", tag,
		WSTOPSIG(status));
		} else
		ALOG(LOG_INFO, "logwrapper", "%s wait() failed: %s (%d)", tag,
		strerror(errno), errno);
		if (seg_fault_on_exit)
		(int )status = 0; // causes SIGSEGV with fault_address = status
		}

		void child(int argc, char* argv[]) {
		// create null terminated argv_child array
		char* argv_child[argc + 1];
		memcpy(argv_child, argv, argc * sizeof(char *));
		argv_child[argc] = NULL;

		if (execvp(argv_child[0], argv_child)) {
		ALOG(LOG_ERROR, "logwrapper",
		"executing %s failed: %s\n", argv_child[0], strerror(errno));
		exit(-1);
		}
		}

		int main(int argc, char* argv[]) {
		pid_t pid;
		int seg_fault_on_exit = 0;

		int parent_ptty;
		int child_ptty;
		char *child_devname = NULL;
		int status = 0xAAAA;
		int rc;

		if (argc < 2) {
		usage();
		@@ -144,43 +59,17 @@ int main(int argc, char* argv[]) {
		usage();
		}

		/* Use ptty instead of socketpair so that STDOUT is not buffered */
		parent_ptty = open("/dev/ptmx", O_RDWR);
		if (parent_ptty < 0) {
		fatal("Cannot create parent ptty\n");
		rc = logwrap(argc, argv, &status);
		if (!rc) {
		if (WIFEXITED(status))
		rc = WEXITSTATUS(status);
		else
		rc = -ECHILD;
		}

		if (grantpt(parent_ptty) \|\| unlockpt(parent_ptty) \|\|
		((child_devname = (char*)ptsname(parent_ptty)) == 0)) {
		fatal("Problem with /dev/ptmx\n");
		}

		pid = fork();
		if (pid < 0) {
		fatal("Failed to fork\n");
		} else if (pid == 0) {
		child_ptty = open(child_devname, O_RDWR);
		if (child_ptty < 0) {
		fatal("Problem with child ptty\n");
		}

		// redirect stdout and stderr
		close(parent_ptty);
		dup2(child_ptty, 1);
		dup2(child_ptty, 2);
		close(child_ptty);

		child(argc - 1, &argv[1]);

		} else {
		// switch user and group to "log"
		// this may fail if we are not root,
		// but in that case switching user/group is unnecessary
		setgid(AID_LOG);
		setuid(AID_LOG);

		parent(argv[1], seg_fault_on_exit, parent_ptty);
		if (seg_fault_on_exit) {
		(int )status = 0; // causes SIGSEGV with fault_address = status
		}

		return 0;
		return rc;
		}