/*
* 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 <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <poll.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <cutils/klog.h>
#include <log/log.h>
#include <logwrap/logwrap.h>
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#define MIN(a,b) (((a)<(b))?(a):(b))
static pthread_mutex_t fd_mutex = PTHREAD_MUTEX_INITIALIZER;
#define ERROR(fmt, args...) \
do { \
fprintf(stderr, fmt, ## args); \
ALOG(LOG_ERROR, "logwrapper", fmt, ## args); \
} while(0)
#define FATAL_CHILD(fmt, args...) \
do { \
ERROR(fmt, ## args); \
_exit(-1); \
} while(0)
#define MAX_KLOG_TAG 16
/* This is a simple buffer that holds up to the first beginning_buf->buf_size
* bytes of output from a command.
*/
#define BEGINNING_BUF_SIZE 0x1000
struct beginning_buf {
char *buf;
size_t alloc_len;
/* buf_size is the usable space, which is one less than the allocated size */
size_t buf_size;
size_t used_len;
};
/* This is a circular buf that holds up to the last ending_buf->buf_size bytes
* of output from a command after the first beginning_buf->buf_size bytes
* (which are held in beginning_buf above).
*/
#define ENDING_BUF_SIZE 0x1000
struct ending_buf {
char *buf;
ssize_t alloc_len;
/* buf_size is the usable space, which is one less than the allocated size */
ssize_t buf_size;
ssize_t used_len;
/* read and write offsets into the circular buffer */
int read;
int write;
};
/* A structure to hold all the abbreviated buf data */
struct abbr_buf {
struct beginning_buf b_buf;
struct ending_buf e_buf;
int beginning_buf_full;
};
/* Collect all the various bits of info needed for logging in one place. */
struct log_info {
int log_target;
char klog_fmt[MAX_KLOG_TAG * 2];
char *btag;
bool abbreviated;
FILE *fp;
struct abbr_buf a_buf;
};
/* Forware declaration */
static void add_line_to_abbr_buf(struct abbr_buf *a_buf, char *linebuf, int linelen);
/* Return 0 on success, and 1 when full */
static int add_line_to_linear_buf(struct beginning_buf *b_buf,
char *line, ssize_t line_len)
{
int full = 0;
if ((line_len + b_buf->used_len) > b_buf->buf_size) {
full = 1;
} else {
/* Add to the end of the buf */
memcpy(b_buf->buf + b_buf->used_len, line, line_len);
b_buf->used_len += line_len;
}
return full;
}
static void add_line_to_circular_buf(struct ending_buf *e_buf,
char *line, ssize_t line_len)
{
ssize_t free_len;
ssize_t needed_space;
int cnt;
if (e_buf->buf == NULL) {
return;
}
if (line_len > e_buf->buf_size) {
return;
}
free_len = e_buf->buf_size - e_buf->used_len;
if (line_len > free_len) {
/* remove oldest entries at read, and move read to make
* room for the new string */
needed_space = line_len - free_len;
e_buf->read = (e_buf->read + needed_space) % e_buf->buf_size;
e_buf->used_len -= needed_space;
}
/* Copy the line into the circular buffer, dealing with possible
* wraparound.
*/
cnt = MIN(line_len, e_buf->buf_size - e_buf->write);
memcpy(e_buf->buf + e_buf->write, line, cnt);
if (cnt < line_len) {
memcpy(e_buf->buf, line + cnt, line_len - cnt);
}
e_buf->used_len += line_len;
e_buf->write = (e_buf->write + line_len) % e_buf->buf_size;
}
/* Log directly to the specified log */
static void do_log_line(struct log_info *log_info, char *line) {
if (log_info->log_target & LOG_KLOG) {
klog_write(6, log_info->klog_fmt, line);
}
if (log_info->log_target & LOG_ALOG) {
ALOG(LOG_INFO, log_info->btag, "%s", line);
}
if (log_info->log_target & LOG_FILE) {
fprintf(log_info->fp, "%s\n", line);
}
}
/* Log to either the abbreviated buf, or directly to the specified log
* via do_log_line() above.
*/
static void log_line(struct log_info *log_info, char *line, int len) {
if (log_info->abbreviated) {
add_line_to_abbr_buf(&log_info->a_buf, line, len);
} else {
do_log_line(log_info, line);
}
}
/*
* The kernel will take a maximum of 1024 bytes in any single write to
* the kernel logging device file, so find and print each line one at
* a time. The allocated size for buf should be at least 1 byte larger
* than buf_size (the usable size of the buffer) to make sure there is
* room to temporarily stuff a null byte to terminate a line for logging.
*/
static void print_buf_lines(struct log_info *log_info, char *buf, int buf_size)
{
char *line_start;
char c;
int i;
line_start = buf;
for (i = 0; i < buf_size; i++) {
if (*(buf + i) == '\n') {
/* Found a line ending, print the line and compute new line_start */
/* Save the next char and replace with \0 */
c = *(buf + i + 1);
*(buf + i + 1) = '\0';
do_log_line(log_info, line_start);
/* Restore the saved char */
*(buf + i + 1) = c;
line_start = buf + i + 1;
} else if (*(buf + i) == '\0') {
/* The end of the buffer, print the last bit */
do_log_line(log_info, line_start);
break;
}
}
/* If the buffer was completely full, and didn't end with a newline, just
* ignore the partial last line.
*/
}
static void init_abbr_buf(struct abbr_buf *a_buf) {
char *new_buf;
memset(a_buf, 0, sizeof(struct abbr_buf));
new_buf = malloc(BEGINNING_BUF_SIZE);
if (new_buf) {
a_buf->b_buf.buf = new_buf;
a_buf->b_buf.alloc_len = BEGINNING_BUF_SIZE;
a_buf->b_buf.buf_size = BEGINNING_BUF_SIZE - 1;
}
new_buf = malloc(ENDING_BUF_SIZE);
if (new_buf) {
a_buf->e_buf.buf = new_buf;
a_buf->e_buf.alloc_len = ENDING_BUF_SIZE;
a_buf->e_buf.buf_size = ENDING_BUF_SIZE - 1;
}
}
static void free_abbr_buf(struct abbr_buf *a_buf) {
free(a_buf->b_buf.buf);
free(a_buf->e_buf.buf);
}
static void add_line_to_abbr_buf(struct abbr_buf *a_buf, char *linebuf, int linelen) {
if (!a_buf->beginning_buf_full) {
a_buf->beginning_buf_full =
add_line_to_linear_buf(&a_buf->b_buf, linebuf, linelen);
}
if (a_buf->beginning_buf_full) {
add_line_to_circular_buf(&a_buf->e_buf, linebuf, linelen);
}
}
static void print_abbr_buf(struct log_info *log_info) {
struct abbr_buf *a_buf = &log_info->a_buf;
/* Add the abbreviated output to the kernel log */
if (a_buf->b_buf.alloc_len) {
print_buf_lines(log_info, a_buf->b_buf.buf, a_buf->b_buf.used_len);
}
/* Print an ellipsis to indicate that the buffer has wrapped or
* is full, and some data was not logged.
*/
if (a_buf->e_buf.used_len == a_buf->e_buf.buf_size) {
do_log_line(log_info, "...\n");
}
if (a_buf->e_buf.used_len == 0) {
return;
}
/* Simplest way to print the circular buffer is allocate a second buf
* of the same size, and memcpy it so it's a simple linear buffer,
* and then cal print_buf_lines on it */
if (a_buf->e_buf.read < a_buf->e_buf.write) {
/* no wrap around, just print it */
print_buf_lines(log_info, a_buf->e_buf.buf + a_buf->e_buf.read,
a_buf->e_buf.used_len);
} else {
/* The circular buffer will always have at least 1 byte unused,
* so by allocating alloc_len here we will have at least
* 1 byte of space available as required by print_buf_lines().
*/
char * nbuf = malloc(a_buf->e_buf.alloc_len);
if (!nbuf) {
return;
}
int first_chunk_len = a_buf->e_buf.buf_size - a_buf->e_buf.read;
memcpy(nbuf, a_buf->e_buf.buf + a_buf->e_buf.read, first_chunk_len);
/* copy second chunk */
memcpy(nbuf + first_chunk_len, a_buf->e_buf.buf, a_buf->e_buf.write);
print_buf_lines(log_info, nbuf, first_chunk_len + a_buf->e_buf.write);
free(nbuf);
}
}
static int parent(const char *tag, int parent_read, pid_t pid,
int *chld_sts, int log_target, bool abbreviated, char *file_path) {
int status = 0;
char buffer[4096];
struct pollfd poll_fds[] = {
[0] = {
.fd = parent_read,
.events = POLLIN,
},
};
int rc = 0;
int fd;
struct log_info log_info;
int a = 0; // start index of unprocessed data
int b = 0; // end index of unprocessed data
int sz;
bool found_child = false;
char tmpbuf[256];
log_info.btag = basename(tag);
if (!log_info.btag) {
log_info.btag = (char*) tag;
}
if (abbreviated && (log_target == LOG_NONE)) {
abbreviated = 0;
}
if (abbreviated) {
init_abbr_buf(&log_info.a_buf);
}
if (log_target & LOG_KLOG) {
snprintf(log_info.klog_fmt, sizeof(log_info.klog_fmt),
"<6>%.*s: %%s\n", MAX_KLOG_TAG, log_info.btag);
}
if ((log_target & LOG_FILE) && !file_path) {
/* No file_path specified, clear the LOG_FILE bit */
log_target &= ~LOG_FILE;
}
if (log_target & LOG_FILE) {
fd = open(file_path, O_WRONLY | O_CREAT, 0664);
if (fd < 0) {
ERROR("Cannot log to file %s\n", file_path);
log_target &= ~LOG_FILE;
} else {
lseek(fd, 0, SEEK_END);
log_info.fp = fdopen(fd, "a");
}
}
log_info.log_target = log_target;
log_info.abbreviated = abbreviated;
while (!found_child) {
if (TEMP_FAILURE_RETRY(poll(poll_fds, ARRAY_SIZE(poll_fds), -1)) < 0) {
ERROR("poll failed\n");
rc = -1;
goto err_poll;
}
if (poll_fds[0].revents & POLLIN) {
sz = TEMP_FAILURE_RETRY(
read(parent_read, &buffer[b], sizeof(buffer) - 1 - b));
sz += b;
// Log one line at a time
for (b = 0; b < sz; b++) {
if (buffer[b] == '\r') {
if (abbreviated) {
/* The abbreviated logging code uses newline as
* the line separator. Lucikly, the pty layer
* helpfully cooks the output of the command
* being run and inserts a CR before NL. So
* I just change it to NL here when doing
* abbreviated logging.
*/
buffer[b] = '\n';
} else {
buffer[b] = '\0';
}
} else if (buffer[b] == '\n') {
buffer[b] = '\0';
log_line(&log_info, &buffer[a], b - a);
a = b + 1;
}
}
if (a == 0 && b == sizeof(buffer) - 1) {
// buffer is full, flush
buffer[b] = '\0';
log_line(&log_info, &buffer[a], b - a);
b = 0;
} else if (a != b) {
// Keep left-overs
b -= a;
memmove(buffer, &buffer[a], b);
a = 0;
} else {
a = 0;
b = 0;
}
}
if (poll_fds[0].revents & POLLHUP) {
int ret;
ret = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
if (ret < 0) {
rc = errno;
ALOG(LOG_ERROR, "logwrap", "waitpid failed with %s\n", strerror(errno));
goto err_waitpid;
}
if (ret > 0) {
found_child = true;
}
}
}
if (chld_sts != NULL) {
*chld_sts = status;
} else {
if (WIFEXITED(status))
rc = WEXITSTATUS(status);
else
rc = -ECHILD;
}
// Flush remaining data
if (a != b) {
buffer[b] = '\0';
log_line(&log_info, &buffer[a], b - a);
}
/* All the output has been processed, time to dump the abbreviated output */
if (abbreviated) {
print_abbr_buf(&log_info);
}
if (WIFEXITED(status)) {
if (WEXITSTATUS(status)) {
snprintf(tmpbuf, sizeof(tmpbuf),
"%s terminated by exit(%d)\n", log_info.btag, WEXITSTATUS(status));
do_log_line(&log_info, tmpbuf);
}
} else {
if (WIFSIGNALED(status)) {
snprintf(tmpbuf, sizeof(tmpbuf),
"%s terminated by signal %d\n", log_info.btag, WTERMSIG(status));
do_log_line(&log_info, tmpbuf);
} else if (WIFSTOPPED(status)) {
snprintf(tmpbuf, sizeof(tmpbuf),
"%s stopped by signal %d\n", log_info.btag, WSTOPSIG(status));
do_log_line(&log_info, tmpbuf);
}
}
err_waitpid:
err_poll:
if (log_target & LOG_FILE) {
fclose(log_info.fp); /* Also closes underlying fd */
}
if (abbreviated) {
free_abbr_buf(&log_info.a_buf);
}
return rc;
}
static 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)) {
FATAL_CHILD("executing %s failed: %s\n", argv_child[0],
strerror(errno));
}
}
int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int_quit,
int log_target, bool abbreviated, char *file_path,
void *unused_opts, int unused_opts_len) {
pid_t pid;
int parent_ptty;
int child_ptty;
struct sigaction intact;
struct sigaction quitact;
sigset_t blockset;
sigset_t oldset;
int rc = 0;
LOG_ALWAYS_FATAL_IF(unused_opts != NULL);
LOG_ALWAYS_FATAL_IF(unused_opts_len != 0);
rc = pthread_mutex_lock(&fd_mutex);
if (rc) {
ERROR("failed to lock signal_fd mutex\n");
goto err_lock;
}
/* Use ptty instead of socketpair so that STDOUT is not buffered */
parent_ptty = TEMP_FAILURE_RETRY(open("/dev/ptmx", O_RDWR));
if (parent_ptty < 0) {
ERROR("Cannot create parent ptty\n");
rc = -1;
goto err_open;
}
char child_devname[64];
if (grantpt(parent_ptty) || unlockpt(parent_ptty) ||
ptsname_r(parent_ptty, child_devname, sizeof(child_devname)) != 0) {
ERROR("Problem with /dev/ptmx\n");
rc = -1;
goto err_ptty;
}
child_ptty = TEMP_FAILURE_RETRY(open(child_devname, O_RDWR));
if (child_ptty < 0) {
ERROR("Cannot open child_ptty\n");
rc = -1;
goto err_child_ptty;
}
sigemptyset(&blockset);
sigaddset(&blockset, SIGINT);
sigaddset(&blockset, SIGQUIT);
pthread_sigmask(SIG_BLOCK, &blockset, &oldset);
pid = fork();
if (pid < 0) {
close(child_ptty);
ERROR("Failed to fork\n");
rc = -1;
goto err_fork;
} else if (pid == 0) {
pthread_mutex_unlock(&fd_mutex);
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
close(parent_ptty);
dup2(child_ptty, 1);
dup2(child_ptty, 2);
close(child_ptty);
child(argc, argv);
} else {
close(child_ptty);
if (ignore_int_quit) {
struct sigaction ignact;
memset(&ignact, 0, sizeof(ignact));
ignact.sa_handler = SIG_IGN;
sigaction(SIGINT, &ignact, &intact);
sigaction(SIGQUIT, &ignact, &quitact);
}
rc = parent(argv[0], parent_ptty, pid, status, log_target,
abbreviated, file_path);
}
if (ignore_int_quit) {
sigaction(SIGINT, &intact, NULL);
sigaction(SIGQUIT, &quitact, NULL);
}
err_fork:
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
err_child_ptty:
err_ptty:
close(parent_ptty);
err_open:
pthread_mutex_unlock(&fd_mutex);
err_lock:
return rc;
}