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/* Copyright (c) 2011 Apple Inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
* HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name(s) of the above
* copyright holders shall not be used in advertising or otherwise to
* promote the sale, use or other dealings in this Software without
* prior written authorization.
*/
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/event.h>
#include <asl.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#define BUF_SIZE 1024
typedef struct {
/* Initialized values */
int fd;
int level;
aslclient aslc;
aslmsg aslm;
/* Buffer for reading */
char buf[BUF_SIZE];
char *w;
int closed;
} asl_redirect;
/* Redirect stdout/stderr to asl */
static void *redirect_thread(void *ctx) {
asl_redirect *fds = ctx;
char *p, *s;
ssize_t nbytes;
struct kevent ev[2];
int kq, n;
/* Setup our kqueue */
kq = kqueue();
EV_SET(&ev[0], fds[0].fd, EVFILT_READ, EV_ADD, 0, 0, 0);
EV_SET(&ev[1], fds[1].fd, EVFILT_READ, EV_ADD, 0, 0, 0);
kevent(kq, ev, 2, NULL, 0, NULL);
/* Set our buffers to empty */
fds[0].w = fds[0].buf;
fds[1].w = fds[1].buf;
/* Start off open */
fds[0].closed = fds[1].closed = 0;
while(!(fds[0].closed && fds[1].closed)) {
n = kevent(kq, NULL, 0, ev, 1, NULL);
if(n < 0) {
asl_log(fds[1].aslc, fds[1].aslm, ASL_LEVEL_ERR, "read failure: %s", strerror(errno));
break;
}
if(n == 1 && ev->filter == EVFILT_READ) {
int fd = ev->ident;
asl_redirect *aslr;
if(fd == fds[0].fd && !fds[0].closed) {
aslr = &fds[0];
} else if(fd == fds[1].fd && !fds[1].closed) {
aslr = &fds[1];
} else {
asl_log(fds[1].aslc, fds[1].aslm, ASL_LEVEL_ERR, "unexpected file descriptor: %d", fd);
break;
}
if(ev->flags & EV_EOF) {
EV_SET(&ev[1], aslr->fd, EVFILT_READ, EV_DELETE, 0, 0, 0);
kevent(kq, &ev[1], 1, NULL, 0, NULL);
aslr->closed = 1;
}
nbytes = read(aslr->fd, aslr->w, BUF_SIZE - (aslr->w - aslr->buf) - 1);
if(nbytes > 0) {
nbytes += (aslr->w - aslr->buf);
aslr->buf[nbytes] = '\0';
/* One line at a time */
for(p=aslr->buf; *p && (p - aslr->buf) < nbytes; p = s + 1) {
// Find null or \n
for(s=p; *s && *s != '\n'; s++);
if(*s == '\n') {
*s='\0';
asl_log(aslr->aslc, aslr->aslm, aslr->level, "%s", p);
} else if(aslr->buf != p) {
memmove(aslr->buf, p, BUF_SIZE);
aslr->w = aslr->buf + (s - p);
break;
} else if(nbytes == BUF_SIZE - 1) {
asl_log(aslr->aslc, aslr->aslm, aslr->level, "%s", p);
aslr->w = aslr->buf;
break;
}
}
}
if(aslr->closed) {
close(aslr->fd);
if(aslr->w > aslr->buf) {
*aslr->w = '\0';
asl_log(aslr->aslc, aslr->aslm, aslr->level, "%s", aslr->buf);
}
}
}
}
return NULL;
}
static pthread_t redirect_pthread;
static void redirect_atexit(void) {
/* stdout is linebuffered, so flush the buffer */
fflush(stdout);
/* close our pipes, causing the redirect thread to terminate */
close(STDOUT_FILENO);
close(STDERR_FILENO);
pthread_join(redirect_pthread, NULL);
}
int console_redirect(aslclient aslc, aslmsg aslm, int stdout_level, int stderr_level) {
int err;
int outpair[2];
int errpair[2];
static asl_redirect readpair[2];
/* Create pipes */
if(pipe(outpair) == -1) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "pipe() failed: %s", strerror(errno));
return errno;
}
if(pipe(errpair) == -1) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "pipe() failed: %s", strerror(errno));
close(outpair[0]);
close(outpair[1]);
return errno;
}
/* Close the read fd but not the write fd on exec */
fcntl(outpair[0], F_SETFD, FD_CLOEXEC);
fcntl(errpair[0], F_SETFD, FD_CLOEXEC);
/* Setup the context to handoff to the read thread */
readpair[0].fd = outpair[0];
readpair[0].level = stdout_level;
readpair[0].aslc = aslc;
readpair[0].aslm = aslm;
readpair[1].fd = errpair[0];
readpair[1].level = stderr_level;
readpair[1].aslc = aslc;
readpair[1].aslm = aslm;
/* Handoff to the read thread */
if((err = pthread_create(&redirect_pthread, NULL, redirect_thread, readpair)) != 0) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "pthread_create() failed: %s", strerror(err));
close(outpair[0]);
close(outpair[1]);
close(errpair[0]);
close(errpair[1]);
return err;
}
/* Replace our stdout fd. force stdout to be line buffered since it defaults to buffered when not a tty */
if(dup2(outpair[1], STDOUT_FILENO) == -1) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "dup2(stdout) failed: %s", strerror(errno));
} else if(setlinebuf(stdout) != 0) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "setlinebuf(stdout) failed, log redirection may be delayed.");
}
/* Replace our stderr fd. stderr is always unbuffered */
if(dup2(errpair[1], STDERR_FILENO) == -1) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "dup2(stderr) failed: %s", strerror(errno));
}
/* Close the duplicate fds since they've been reassigned */
close(outpair[1]);
close(errpair[1]);
/* Register an atexit handler to wait for the logs to flush */
if(atexit(redirect_atexit) != 0) {
asl_log(aslc, aslm, ASL_LEVEL_ERR, "atexit(redirect_atexit) failed: %s", strerror(errno));
}
return 0;
}
#ifdef DEBUG_CONSOLE_REDIRECT
int main(int argc, char **argv) {
console_redirect(NULL, NULL, ASL_LEVEL_NOTICE, ASL_LEVEL_ERR);
fprintf(stderr, "TEST ERR1\n");
fprintf(stdout, "TEST OUT1\n");
fprintf(stderr, "TEST ERR2\n");
fprintf(stdout, "TEST OUT2\n");
system("/bin/echo SYST OUT");
system("/bin/echo SYST ERR >&2");
fprintf(stdout, "TEST OUT3\n");
fprintf(stdout, "TEST OUT4");
fprintf(stderr, "TEST ERR3\n");
fprintf(stderr, "TEST ERR4");
exit(0);
}
#endif
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