logwrapper: split into liblogwrap and the executable itself
Abstracting the functionality of logwrapper into a library and making
use of it for the logwrapper executable.
Change-Id: I2bcf722413f3a8454c6f52137dec86c4477fb8b5
diff --git a/logwrapper/Android.mk b/logwrapper/Android.mk
index 5fd6356..b4b6b29 100644
--- a/logwrapper/Android.mk
+++ b/logwrapper/Android.mk
@@ -1,7 +1,34 @@
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)
diff --git a/logwrapper/include/logwrap/logwrap.h b/logwrapper/include/logwrap/logwrap.h
new file mode 100644
index 0000000..a58f238
--- /dev/null
+++ b/logwrapper/include/logwrap/logwrap.h
@@ -0,0 +1,27 @@
+/* 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 */
diff --git a/logwrapper/logwrap.c b/logwrapper/logwrap.c
new file mode 100644
index 0000000..302a739
--- /dev/null
+++ b/logwrapper/logwrap.c
@@ -0,0 +1,161 @@
+/*
+ * 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;
+}
diff --git a/logwrapper/logwrapper.c b/logwrapper/logwrapper.c
index dd777c0..4f1bff9 100644
--- a/logwrapper/logwrapper.c
+++ b/logwrapper/logwrapper.c
@@ -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 "private/android_filesystem_config.h"
+#include <logwrap/logwrap.h>
+
#include "cutils/log.h"
void fatal(const char *msg) {
@@ -45,90 +40,10 @@
" 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 @@
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");
+ if (seg_fault_on_exit) {
+ *(int *)status = 0; // causes SIGSEGV with fault_address = status
}
- 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);
- }
-
- return 0;
+ return rc;
}