1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <string.h> 18 #include <sys/types.h> 19 #include <sys/wait.h> 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <unistd.h> 23 #include <errno.h> 24 #include <fcntl.h> 25 26 #include "private/android_filesystem_config.h" 27 #include "cutils/log.h" 28 29 int parent(const char *tag, int parent_read) { 30 int status; 31 char buffer[4096]; 32 33 int a = 0; // start index of unprocessed data 34 int b = 0; // end index of unprocessed data 35 int sz; 36 while ((sz = read(parent_read, &buffer[b], sizeof(buffer) - 1 - b)) > 0) { 37 38 sz += b; 39 // Log one line at a time 40 for (b = 0; b < sz; b++) { 41 if (buffer[b] == '\r') { 42 buffer[b] = '\0'; 43 } else if (buffer[b] == '\n') { 44 buffer[b] = '\0'; 45 46 LOG(LOG_INFO, tag, "%s", &buffer[a]); 47 a = b + 1; 48 } 49 } 50 51 if (a == 0 && b == sizeof(buffer) - 1) { 52 // buffer is full, flush 53 buffer[b] = '\0'; 54 LOG(LOG_INFO, tag, "%s", &buffer[a]); 55 b = 0; 56 } else if (a != b) { 57 // Keep left-overs 58 b -= a; 59 memmove(buffer, &buffer[a], b); 60 a = 0; 61 } else { 62 a = 0; 63 b = 0; 64 } 65 66 } 67 // Flush remaining data 68 if (a != b) { 69 buffer[b] = '\0'; 70 LOG(LOG_INFO, tag, "%s", &buffer[a]); 71 } 72 status = 0xAAAA; 73 if (wait(&status) != -1) { // Wait for child 74 if (WIFEXITED(status)) { 75 if (WEXITSTATUS(status) != 0) { 76 LOG(LOG_INFO, "logwrapper", "%s terminated by exit(%d)", tag, 77 WEXITSTATUS(status)); 78 } 79 return WEXITSTATUS(status); 80 } else if (WIFSIGNALED(status)) 81 LOG(LOG_INFO, "logwrapper", "%s terminated by signal %d", tag, 82 WTERMSIG(status)); 83 else if (WIFSTOPPED(status)) 84 LOG(LOG_INFO, "logwrapper", "%s stopped by signal %d", tag, 85 WSTOPSIG(status)); 86 } else 87 LOG(LOG_INFO, "logwrapper", "%s wait() failed: %s (%d)", tag, 88 strerror(errno), errno); 89 return -EAGAIN; 90 } 91 92 void child(int argc, const char**argv) { 93 // create null terminated argv_child array 94 char* argv_child[argc + 1]; 95 memcpy(argv_child, argv, argc * sizeof(char *)); 96 argv_child[argc] = NULL; 97 98 // XXX: PROTECT FROM VIKING KILLER 99 if (execv(argv_child[0], argv_child)) { 100 LOG(LOG_ERROR, "logwrapper", 101 "executing %s failed: %s", argv_child[0], strerror(errno)); 102 } 103 _exit(1); 104 } 105 106 int logwrap(int argc, const char* argv[], int background) 107 { 108 pid_t pid; 109 110 int parent_ptty; 111 int child_ptty; 112 char child_devname[64]; // same size as libc/unistd/ptsname_r.c 113 114 /* Use ptty instead of socketpair so that STDOUT is not buffered */ 115 parent_ptty = open("/dev/ptmx", O_RDWR); 116 if (parent_ptty < 0) { 117 LOG(LOG_ERROR, "logwrapper", "Cannot create parent ptty"); 118 return -errno; 119 } 120 121 if (grantpt(parent_ptty) || unlockpt(parent_ptty) || 122 ptsname_r(parent_ptty, child_devname, sizeof(child_devname))) { 123 close(parent_ptty); 124 LOG(LOG_ERROR, "logwrapper", "Problem with /dev/ptmx"); 125 return -1; 126 } 127 128 pid = fork(); 129 if (pid < 0) { 130 close(parent_ptty); 131 LOG(LOG_ERROR, "logwrapper", "Failed to fork"); 132 return -errno; 133 } else if (pid == 0) { 134 /* 135 * Child 136 */ 137 child_ptty = open(child_devname, O_RDWR); 138 if (child_ptty < 0) { 139 close(parent_ptty); 140 LOG(LOG_ERROR, "logwrapper", "Problem with child ptty"); 141 _exit(errno < 128 ? errno : 1); // XXX lame 142 } 143 144 // redirect stdout and stderr 145 close(parent_ptty); 146 dup2(child_ptty, 1); 147 dup2(child_ptty, 2); 148 close(child_ptty); 149 150 if (background) { 151 int fd = open("/dev/cpuctl/bg_non_interactive/tasks", O_WRONLY); 152 if (fd >= 0) { 153 char text[64]; 154 sprintf(text, "%d", getpid()); 155 if (write(fd, text, strlen(text)) < 0) { 156 LOG(LOG_WARN, "logwrapper", 157 "Unable to background process (%s)", strerror(errno)); 158 } 159 close(fd); 160 } else { 161 LOG(LOG_WARN, "logwrapper", 162 "Unable to background process (%s)", strerror(errno)); 163 } 164 } 165 166 child(argc, argv); 167 } else { 168 /* 169 * Parent 170 */ 171 int rc = parent(argv[0], parent_ptty); 172 close(parent_ptty); 173 return rc; 174 } 175 176 return 0; 177 } 178
