diff options
Diffstat (limited to 'vdr.c')
| -rw-r--r-- | vdr.c | 91 |
1 files changed, 86 insertions, 5 deletions
@@ -22,13 +22,17 @@ * * The project's page is at http://www.cadsoft.de/vdr * - * $Id: vdr.c 1.223 2005/12/30 15:07:47 kls Exp $ + * $Id: vdr.c 1.224 2005/12/31 13:30:11 kls Exp $ */ #include <getopt.h> +#include <grp.h> #include <locale.h> +#include <pwd.h> #include <signal.h> #include <stdlib.h> +#include <sys/capability.h> +#include <sys/prctl.h> #include <termios.h> #include <unistd.h> #include "audio.h" @@ -72,6 +76,57 @@ static int Interrupted = 0; +static bool SetUser(const char *UserName) +{ + if (UserName) { + struct passwd *user = getpwnam(UserName); + if (!user) { + fprintf(stderr, "vdr: unknown user: '%s'\n", UserName); + return false; + } + if (setgid(user->pw_gid) < 0) { + fprintf(stderr, "vdr: cannot set group id %u: %s\n", (unsigned int)user->pw_gid, strerror(errno)); + return false; + } + if (initgroups(user->pw_name, user->pw_gid) < 0) { + fprintf(stderr, "vdr: cannot set supplemental group ids for user %s: %s\n", user->pw_name, strerror(errno)); + return false; + } + if (setuid(user->pw_uid) < 0) { + fprintf(stderr, "vdr: cannot set user id %u: %s\n", (unsigned int)user->pw_uid, strerror(errno)); + return false; + } + } + return true; +} + +static bool SetCapSysTime(void) +{ + // drop all capabilities except cap_sys_time + cap_t caps = cap_from_text("= cap_sys_time=ep"); + if (!caps) { + fprintf(stderr, "vdr: cap_from_text failed: %s\n", strerror(errno)); + return false; + } + if (cap_set_proc(caps) == -1) { + fprintf(stderr, "vdr: cap_set_proc failed: %s\n", strerror(errno)); + cap_free(caps); + return false; + } + cap_free(caps); + return true; +} + +static bool SetKeepCaps(bool On) +{ + // set keeping capabilities during setuid() on/off + if (prctl(PR_SET_KEEPCAPS, On ? 1 : 0, 0, 0, 0) != 0) { + fprintf(stderr, "vdr: prctl failed\n"); + return false; + } + return true; +} + static void SignalHandler(int signum) { if (signum != SIGPIPE) { @@ -102,11 +157,14 @@ int main(int argc, char *argv[]) // Command line options: +#define DEFAULTVDRUSER "vdr" #define DEFAULTSVDRPPORT 2001 #define DEFAULTWATCHDOG 0 // seconds #define DEFAULTPLUGINDIR PLUGINDIR #define DEFAULTEPGDATAFILENAME "epg.data" + bool StartedAsRoot = false; + const char *VdrUser = DEFAULTVDRUSER; int SVDRPport = DEFAULTSVDRPPORT; const char *AudioCommand = NULL; const char *ConfigDirectory = NULL; @@ -157,6 +215,7 @@ int main(int argc, char *argv[]) { "record", required_argument, NULL, 'r' }, { "shutdown", required_argument, NULL, 's' }, { "terminal", required_argument, NULL, 't' }, + { "user", required_argument, NULL, 'u' }, { "version", no_argument, NULL, 'V' }, { "vfat", no_argument, NULL, 'v' | 0x100 }, { "video", required_argument, NULL, 'v' }, @@ -165,7 +224,7 @@ int main(int argc, char *argv[]) }; int c; - while ((c = getopt_long(argc, argv, "a:c:dD:E:g:hl:L:mp:P:r:s:t:v:Vw:", long_options, NULL)) != -1) { + while ((c = getopt_long(argc, argv, "a:c:dD:E:g:hl:L:mp:P:r:s:t:u:v:Vw:", long_options, NULL)) != -1) { switch (c) { case 'a': AudioCommand = optarg; break; @@ -251,6 +310,9 @@ int main(int argc, char *argv[]) return 2; } break; + case 'u': if (*optarg) + VdrUser = optarg; + break; case 'V': DisplayVersion = true; break; case 'v' | 0x100: @@ -273,6 +335,20 @@ int main(int argc, char *argv[]) } } + // Set user id in case we were started as root: + + if (getuid() == 0) { + StartedAsRoot = true; + if (!SetKeepCaps(true)) + return 2; + if (!SetUser(VdrUser)) + return 2; + if (!SetKeepCaps(false)) + return 2; + if (!SetCapSysTime()) + return 2; + } + // Help and version info: if (DisplayHelp || DisplayVersion) { @@ -288,12 +364,12 @@ int main(int argc, char *argv[]) " -D NUM, --device=NUM use only the given DVB device (NUM = 0, 1, 2...)\n" " there may be several -D options (default: all DVB\n" " devices will be used)\n" - " -E FILE --epgfile=FILE write the EPG data into the given FILE (default is\n" + " -E FILE, --epgfile=FILE write the EPG data into the given FILE (default is\n" " '%s' in the video directory)\n" " '-E-' disables this\n" " if FILE is a directory, the default EPG file will be\n" " created in that directory\n" - " -g DIR --grab=DIR write images from the SVDRP command GRAB into the\n" + " -g DIR, --grab=DIR write images from the SVDRP command GRAB into the\n" " given DIR; DIR must be the full path name of an\n" " existing directory, without any \"..\", double '/'\n" " or symlinks (default: none, same as -g-)\n" @@ -316,6 +392,8 @@ int main(int argc, char *argv[]) " -r CMD, --record=CMD call CMD before and after a recording\n" " -s CMD, --shutdown=CMD call CMD to shutdown the computer\n" " -t TTY, --terminal=TTY controlling tty\n" + " -u USER, --user=USER run as user USER (default: %s); only applicable\n" + " if started as root\n" " -v DIR, --video=DIR use DIR as video directory (default: %s)\n" " -V, --version print version information and exit\n" " --vfat encode special characters in recording names to\n" @@ -328,6 +406,7 @@ int main(int argc, char *argv[]) LIRC_DEVICE, DEFAULTSVDRPPORT, RCU_DEVICE, + DEFAULTVDRUSER, VideoDirectory, DEFAULTWATCHDOG ); @@ -378,7 +457,7 @@ int main(int argc, char *argv[]) if (DaemonMode) { if (daemon(1, 0) == -1) { - fprintf(stderr, "%m\n"); + fprintf(stderr, "vdr: %m\n"); esyslog("ERROR: %m"); return 2; } @@ -392,6 +471,8 @@ int main(int argc, char *argv[]) } isyslog("VDR version %s started", VDRVERSION); + if (StartedAsRoot) + isyslog("switched to user '%s'", VdrUser); // Main program loop variables - need to be here to have them initialized before any EXIT(): |