Merge "logwrapper: split into liblogwrap and the executable itself"

4 files changed, 230 insertions, 126 deletions

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 <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;
 }