From 9ce153ce7167c11adba8ac225edc7a707e97c6eb Mon Sep 17 00:00:00 2001 From: Federico Ceratto Date: Wed, 30 Mar 2016 22:40:42 +0100 Subject: Imported Upstream version 1.0.0 --- src/daemon.c | 317 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 317 insertions(+) create mode 100755 src/daemon.c (limited to 'src/daemon.c') diff --git a/src/daemon.c b/src/daemon.c new file mode 100755 index 000000000..268814798 --- /dev/null +++ b/src/daemon.c @@ -0,0 +1,317 @@ +#ifdef HAVE_CONFIG_H +#include +#endif +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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); +} -- cgit v1.2.3