Imported Upstream version 1.0.0upstream/1.0.0

1 files changed, 317 insertions, 0 deletions

diff --git a/src/daemon.c b/src/daemon.c
new file mode 100755
index 00000000..26881479
--- /dev/null
+++ b/src/daemon.c
@@ -0,0 +1,317 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <pthread.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <execinfo.h>
+
+#include "common.h"
+#include "appconfig.h"
+#include "log.h"
+#include "web_client.h"
+#include "plugins_d.h"
+#include "rrd.h"
+#include "popen.h"
+#include "main.h"
+#include "daemon.h"
+
+void sig_handler(int signo)
+{
+	switch(signo) {
+		case SIGILL:
+		case SIGABRT:
+		case SIGFPE:
+		case SIGSEGV:
+		case SIGBUS:
+		case SIGSYS:
+		case SIGTRAP:
+		case SIGXCPU:
+		case SIGXFSZ:
+			infoerr("Death signaled exit (signal %d).", signo);
+			signal(signo, SIG_DFL);
+			break;
+
+		case SIGKILL:
+		case SIGTERM:
+		case SIGQUIT:
+		case SIGINT:
+		case SIGHUP:
+		case SIGUSR1:
+		case SIGUSR2:
+			infoerr("Signaled exit (signal %d).", signo);
+			signal(SIGPIPE, SIG_IGN);
+			signal(SIGTERM, SIG_IGN);
+			signal(SIGQUIT, SIG_IGN);
+			signal(SIGHUP,  SIG_IGN);
+			signal(SIGINT,  SIG_IGN);
+			signal(SIGCHLD, SIG_IGN);
+			netdata_cleanup_and_exit(1);
+			break;
+
+		case SIGPIPE:
+			infoerr("Signaled PIPE (signal %d).", signo);
+			// this is received when web clients send a reset
+			// no need to log it.
+			// infoerr("Ignoring signal %d.", signo);
+			break;
+
+		default:
+			info("Signal %d received. Falling back to default action for it.", signo);
+			signal(signo, SIG_DFL);
+			break;
+	}
+}
+
+char rundir[FILENAME_MAX + 1] = "/var/run/netdata";
+char pidfile[FILENAME_MAX + 1] = "";
+void prepare_rundir() {
+	if(getuid() != 0) {
+		mkdir("/run/user", 0775);
+		snprintf(rundir, FILENAME_MAX, "/run/user/%d", getuid());
+		mkdir(rundir, 0775);
+		snprintf(rundir, FILENAME_MAX, "/run/user/%d/netdata", getuid());
+	}
+
+	snprintf(pidfile, FILENAME_MAX, "%s/netdata.pid", rundir);
+
+	if(mkdir(rundir, 0775) != 0) {
+		if(errno != EEXIST) error("Cannot create directory '%s'.", rundir);
+	}
+}
+
+int become_user(const char *username)
+{
+	struct passwd *pw = getpwnam(username);
+	if(!pw) {
+		error("User %s is not present.", username);
+		return -1;
+	}
+
+	if(chown(rundir, pw->pw_uid, pw->pw_gid) != 0) {
+		error("Cannot chown directory '%s' to user %s.", rundir, username);
+		return -1;
+	}
+
+	if(setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
+		error("Cannot switch to user's %s group (gid: %d).", username, pw->pw_gid);
+		return -1;
+	}
+
+	if(setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
+		error("Cannot switch to user %s (uid: %d).", username, pw->pw_uid);
+		return -1;
+	}
+
+	if(setgid(pw->pw_gid) != 0) {
+		error("Cannot switch to user's %s group (gid: %d).", username, pw->pw_gid);
+		return -1;
+	}
+	if(setegid(pw->pw_gid) != 0) {
+		error("Cannot effectively switch to user's %s group (gid: %d).", username, pw->pw_gid);
+		return -1;
+	}
+	if(setuid(pw->pw_uid) != 0) {
+		error("Cannot switch to user %s (uid: %d).", username, pw->pw_uid);
+		return -1;
+	}
+	if(seteuid(pw->pw_uid) != 0) {
+		error("Cannot effectively switch to user %s (uid: %d).", username, pw->pw_uid);
+		return -1;
+	}
+
+	return(0);
+}
+
+int become_daemon(int dont_fork, int close_all_files, const char *user, const char *input, const char *output, const char *error, const char *access, int *access_fd, FILE **access_fp)
+{
+	fflush(NULL);
+
+	// open the files before forking
+	int input_fd = -1, output_fd = -1, error_fd = -1, dev_null;
+
+	if(input && *input) {
+		if((input_fd = open(input, O_RDONLY, 0666)) == -1) {
+			error("Cannot open input file '%s'.", input);
+			return -1;
+		}
+	}
+
+	if(output && *output) {
+		if((output_fd = open(output, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) {
+			error("Cannot open output log file '%s'", output);
+			if(input_fd != -1) close(input_fd);
+			return -1;
+		}
+	}
+
+	if(error && *error) {
+		if((error_fd = open(error, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) {
+			error("Cannot open error log file '%s'.", error);
+			if(input_fd != -1) close(input_fd);
+			if(output_fd != -1) close(output_fd);
+			return -1;
+		}
+	}
+
+	if(access && *access && access_fd) {
+		if((*access_fd = open(access, O_RDWR | O_APPEND | O_CREAT, 0666)) == -1) {
+			error("Cannot open access log file '%s'", access);
+			if(input_fd != -1) close(input_fd);
+			if(output_fd != -1) close(output_fd);
+			if(error_fd != -1) close(error_fd);
+			return -1;
+		}
+
+		if(access_fp) {
+			*access_fp = fdopen(*access_fd, "w");
+			if(!*access_fp) {
+				error("Cannot migrate file's '%s' fd %d.", access, *access_fd);
+				if(input_fd != -1) close(input_fd);
+				if(output_fd != -1) close(output_fd);
+				if(error_fd != -1) close(error_fd);
+				close(*access_fd);
+				*access_fd = -1;
+				return -1;
+			}
+		}
+	}
+
+	if((dev_null = open("/dev/null", O_RDWR, 0666)) == -1) {
+		perror("Cannot open /dev/null");
+		if(input_fd != -1) close(input_fd);
+		if(output_fd != -1) close(output_fd);
+		if(error_fd != -1) close(error_fd);
+		if(access && access_fd && *access_fd != -1) {
+			close(*access_fd);
+			*access_fd = -1;
+			if(access_fp) {
+				fclose(*access_fp);
+				*access_fp = NULL;
+			}
+		}
+		return -1;
+	}
+
+	// all files opened
+	// lets do it
+
+	if(!dont_fork) {
+		int i = fork();
+		if(i == -1) {
+			perror("cannot fork");
+			exit(1);
+		}
+		if(i != 0) {
+			exit(0); // the parent
+		}
+
+		// become session leader
+		if (setsid() < 0) {
+			perror("Cannot become session leader.");
+			exit(2);
+		}
+	}
+
+	signal(SIGCHLD,  SIG_IGN);
+	signal(SIGHUP,   SIG_IGN);
+	signal(SIGWINCH, SIG_IGN);
+
+	// fork() again
+	if(!dont_fork) {
+		int i = fork();
+		if(i == -1) {
+			perror("cannot fork");
+			exit(1);
+		}
+		if(i != 0) {
+			exit(0); // the parent
+		}
+	}
+
+	// Set new file permissions
+	umask(0);
+
+	// close all files
+	if(close_all_files) {
+		int i;
+		for(i = (int) (sysconf(_SC_OPEN_MAX) - 1); i > 0; i--)
+			if(
+				((access_fd && i != *access_fd) || !access_fd)
+				&& i != dev_null
+				&& i != input_fd
+				&& i != output_fd
+				&& i != error_fd
+				&& fd_is_valid(i)
+				) close(i);
+	}
+	else {
+		close(STDIN_FILENO);
+		close(STDOUT_FILENO);
+		close(STDERR_FILENO);
+	}
+
+	// put the opened files
+	// to our standard file descriptors
+	if(input_fd != -1) {
+		if(input_fd != STDIN_FILENO) {
+			dup2(input_fd, STDIN_FILENO);
+			close(input_fd);
+		}
+		input_fd = -1;
+	}
+	else dup2(dev_null, STDIN_FILENO);
+
+	if(output_fd != -1) {
+		if(output_fd != STDOUT_FILENO) {
+			dup2(output_fd, STDOUT_FILENO);
+			close(output_fd);
+		}
+		output_fd = -1;
+	}
+	else dup2(dev_null, STDOUT_FILENO);
+
+	if(error_fd != -1) {
+		if(error_fd != STDERR_FILENO) {
+			dup2(error_fd, STDERR_FILENO);
+			close(error_fd);
+		}
+		error_fd = -1;
+	}
+	else dup2(dev_null, STDERR_FILENO);
+
+	// close /dev/null
+	if(dev_null != STDIN_FILENO && dev_null != STDOUT_FILENO && dev_null != STDERR_FILENO)
+		close(dev_null);
+
+	// generate our pid file
+	{
+		unlink(pidfile);
+		int fd = open(pidfile, O_RDWR | O_CREAT, 0666);
+		if(fd >= 0) {
+			char b[100];
+			sprintf(b, "%d\n", getpid());
+			ssize_t i = write(fd, b, strlen(b));
+			if(i <= 0) perror("Cannot write pid to file.");
+			close(fd);
+		}
+	}
+
+	if(user && *user) {
+		if(become_user(user) != 0) {
+			error("Cannot become user '%s'. Continuing as we are.", user);
+		}
+		else info("Successfully became user '%s'.", user);
+	}
+
+	return(0);
+}