X-Git-Url: http://git.code-monkey.de/?a=blobdiff_plain;f=src%2Fmain.c;h=10b9de3dce4bcdd923226dbf2a1816370d3fd10f;hb=4c431fe65269e9b1d452855b9df8cfe80683b691;hp=d1351ddc080f9c76a761023f1f43fb2e288975b6;hpb=a76733ea91c6a1d42dfbb50631fa214cc284c3bf;p=umurmur.git diff --git a/src/main.c b/src/main.c index d1351dd..10b9de3 100644 --- a/src/main.c +++ b/src/main.c @@ -1,5 +1,5 @@ -/* Copyright (C) 2009-2010, Martin Johansson - Copyright (C) 2005-2010, Thorvald Natvig +/* Copyright (C) 2009-2012, Martin Johansson + Copyright (C) 2005-2012, Thorvald Natvig All rights reserved. @@ -29,19 +29,24 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ - #include #include #include #include #include #include +#include +#include #include -#include #include #include #include - +#ifdef _POSIX_PRIORITY_SCHEDULING +#if (_POSIX_PRIORITY_SCHEDULING > 0) +#define POSIX_PRIORITY_SCHEDULING +#include +#endif +#endif #include "server.h" #include "ssl.h" #include "channel.h" @@ -56,25 +61,112 @@ char *bindaddr; void lockfile(const char *pidfile) { - int lfp; + int lfp, flags; char str[16]; - - lfp = open(pidfile, O_RDWR|O_CREAT, 0640); + + /* Don't use O_TRUNC here -- we want to leave the PID file + * unmodified if we cannot lock it. + */ + lfp = open(pidfile, O_WRONLY|O_CREAT, 0640); if (lfp < 0) Log_fatal("Cannot open PID-file %s for writing", pidfile); - sprintf(str,"%d\n", getpid()); + + /* Try to lock the file. */ + if (lockf(lfp, F_TLOCK, 0) < 0) { + close(lfp); + + if (errno == EACCES || errno == EAGAIN) + Log_fatal("PID file is locked -- uMurmur already running?"); + + Log_fatal("Cannot lock PID file: %s", strerror(errno)); + } + + /* Now that we locked the file, erase its contents. */ + if (ftruncate(lfp, 0) < 0) { + close(lfp); + Log_fatal("Cannot truncate PID file: %s", strerror(errno)); + } + + snprintf(str,16,"%d\n", getpid()); write(lfp, str, strlen(str)); /* record pid to lockfile */ Log_info("PID-file: %s", pidfile); + + /* If uMurmur ever starts to fork()+exec(), we don't want it to + * leak the fd to the forked process though. Set the close-on-exec + * flag to prevent leakage. + */ + flags = fcntl(lfp, F_GETFD, 0); + flags |= FD_CLOEXEC; + fcntl(lfp, F_SETFD, (long) flags); + + /* Don't close(lfp) here! + * We want the fd to remain opened so the lock is held until the + * process exits. + */ + lfp = -1; } +/* Drops privileges (if configured to do so). */ +static void switch_user(void) +{ + struct passwd *pwd; + struct group *grp = NULL; + const char *username, *groupname; + gid_t gid; + + username = getStrConf(USERNAME); + groupname = getStrConf(GROUPNAME); + + if (!*username) { + /* It's an error to specify groupname + * but leave username empty. + */ + if (*groupname) + Log_fatal("username missing"); + + /* Nothing to do. */ + return; + } + + pwd = getpwnam(username); + if (!pwd) + Log_fatal("Unknown user '%s'", username); + + if (!*groupname) + gid = pwd->pw_gid; + else { + grp = getgrnam(groupname); + + if (!grp) + Log_fatal("Unknown group '%s'", groupname); + + gid = grp->gr_gid; + } + + if (initgroups(pwd->pw_name, gid)) + Log_fatal("initgroups() failed: %s", strerror(errno)); + + if (setgid(gid)) + Log_fatal("setgid() failed: %s", strerror(errno)); + + if (setuid(pwd->pw_uid)) + Log_fatal("setuid() failed: %s", strerror(errno)); + + if (!grp) + grp = getgrgid(gid); + if (!grp) + Log_fatal("getgrgid() failed: %s", strerror(errno)); + + Log_info("Switch to user '%s' group '%s'", pwd->pw_name, grp->gr_name); +} void signal_handler(int sig) { switch(sig) { case SIGHUP: - /* XXX - do stuff? */ - Log_info("HUP signal"); + Log_info("HUP signal received."); + Log_reset(); break; case SIGTERM: Log_info("TERM signal. Shutting down."); @@ -111,6 +203,7 @@ void daemonize() } +#ifdef POSIX_PRIORITY_SCHEDULING void setscheduler() { int rc; @@ -122,15 +215,19 @@ void setscheduler() if (rc < 0) Log_warn("Failed to set scheduler: %s", strerror(errno)); } +#endif void printhelp() { printf("uMurmur version %s. Mumble protocol %d.%d.%d\n", UMURMUR_VERSION, PROTVER_MAJOR, PROTVER_MINOR, PROTVER_PATCH); - printf("Usage: umurmurd [-d] [-p ] [-c ] [-h]\n"); - printf(" -d - Do not deamonize\n"); - printf(" -p - Write PID to this file\n"); - printf(" -c - Specify configuration file\n"); + printf("Usage: umurmurd [-d] [-r] [-h] [-p ] [-t] [-c ] [-a ] [-b ]\n"); + printf(" -d - Do not daemonize - run in foreground.\n"); +#ifdef POSIX_PRIORITY_SCHEDULING printf(" -r - Run with realtime priority\n"); +#endif + printf(" -p - Write PID to this file\n"); + printf(" -c - Specify configuration file (default %s)\n", DEFAULT_CONFIG); + printf(" -t - Test config. Error message to stderr + non-zero exit code on error\n"); printf(" -a
- Bind to IP address\n"); printf(" -b - Bind to port\n"); printf(" -h - Print this help\n"); @@ -140,13 +237,20 @@ void printhelp() int main(int argc, char **argv) { bool_t nodaemon = false; +#ifdef POSIX_PRIORITY_SCHEDULING bool_t realtime = false; +#endif + bool_t testconfig = false; char *conffile = NULL, *pidfile = NULL; int c; struct utsname utsbuf; /* Arguments */ - while ((c = getopt(argc, argv, "drp:c:a:b:h")) != EOF) { +#ifdef POSIX_PRIORITY_SCHEDULING + while ((c = getopt(argc, argv, "drp:c:a:b:ht")) != EOF) { +#else + while ((c = getopt(argc, argv, "dp:c:a:b:ht")) != EOF) { +#endif switch(c) { case 'c': conffile = optarg; @@ -166,29 +270,49 @@ int main(int argc, char **argv) case 'h': printhelp(); break; + case 't': + testconfig = true; + break; +#ifdef POSIX_PRIORITY_SCHEDULING case 'r': realtime = true; break; +#endif default: fprintf(stderr, "Unrecognized option\n"); printhelp(); break; } } - - if (Conf_init(conffile) != 0) { - fprintf(stderr, "Configuration error\n"); - exit(1); + + if (testconfig) { + if (!Conf_ok(conffile)) + exit(1); + else + exit(0); } + /* Initialize the config subsystem early; + * switch_user() will need to read some config variables as well as logging. + */ + Conf_init(conffile); + + /* Logging to terminal if not daemonizing, otherwise to syslog or log file. + */ if (!nodaemon) { - Log_init(false); daemonize(); + Log_init(false); if (pidfile != NULL) lockfile(pidfile); + + switch_user(); + + /* Reopen log file. If user switch results in access denied, we catch + * it early. + */ + Log_reset(); } - else - Log_init(true); + else Log_init(true); signal(SIGCHLD, SIG_IGN); /* ignore child */ signal(SIGTSTP, SIG_IGN); /* ignore tty signals */ @@ -213,8 +337,10 @@ int main(int argc, char **argv) Chan_init(); Client_init(); +#ifdef POSIX_PRIORITY_SCHEDULING if (realtime) setscheduler(); +#endif Server_run();