faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

util: add function for dropping root privileges

Browse source 
Share the code for dropping supplementary groups and setting effective,
saved, and real user UID/GID between system drivers.
This commit is contained in:
Miroslav Lichvar 2015-12-08 17:16:45 +01:00
parent 334ac06102
commit 3cf6acdf24
6 changed files with 28 additions and 34 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
sys_linux.c
View file

@ -45,7 +45,6 @@
#ifdef FEAT_PRIVDROP
#include <sys/prctl.h>
#include <sys/capability.h>
#include <grp.h>
#endif
#ifdef FEAT_SCFILTER
@ -66,6 +65,7 @@
#include "sys_timex.h"
#include "conf.h"
#include "logging.h"
#include "util.h"
/* Frequency scale to convert from ppm to the timex freq */
#define FREQ_SCALE (double)(1 << 16)
@ -409,17 +409,7 @@ SYS_Linux_DropRoot(uid_t uid, gid_t gid)
LOG_FATAL(LOGF_SysLinux, "prctl() failed");
}
if (setgroups(0, NULL)) {
LOG_FATAL(LOGF_SysLinux, "setgroups() failed");
}
if (setgid(gid)) {
LOG_FATAL(LOGF_SysLinux, "setgid(%d) failed", gid);
}
if (setuid(uid)) {
LOG_FATAL(LOGF_SysLinux, "setuid(%d) failed", uid);
}
UTI_DropRoot(uid, gid);
if ((cap = cap_from_text("cap_net_bind_service,cap_sys_time=ep")) == NULL) {
LOG_FATAL(LOGF_SysLinux, "cap_from_text() failed");
@ -430,8 +420,6 @@ SYS_Linux_DropRoot(uid_t uid, gid_t gid)
}
cap_free(cap);
DEBUG_LOG(LOGF_SysLinux, "Root dropped to uid %d gid %d", uid, gid);
}
#endif

11
sys_macosx.c
View file

@ -419,16 +419,7 @@ void SYS_MacOSX_DropRoot(uid_t uid, gid_t gid)
{
PRV_StartHelper();
if (setgroups(0, NULL))
LOG_FATAL(LOGF_SysMacOSX, "setgroups() failed : %s", strerror(errno));
if (setgid(gid))
LOG_FATAL(LOGF_SysMacOSX, "setgid(%d) failed : %s", gid, strerror(errno));
if (setuid(uid))
LOG_FATAL(LOGF_SysMacOSX, "setuid(%d) failed : %s", uid, strerror(errno));
DEBUG_LOG(LOGF_SysMacOSX, "Root dropped to uid %d gid %d", uid, gid);
UTI_DropRoot(uid, gid);
}
#endif

11
sys_netbsd.c
View file

@ -127,16 +127,7 @@ SYS_NetBSD_DropRoot(uid_t uid, gid_t gid)
PRV_StartHelper();
if (setgroups(0, NULL))
LOG_FATAL(LOGF_SysNetBSD, "setgroups() failed : %s", strerror(errno));
if (setgid(gid))
LOG_FATAL(LOGF_SysNetBSD, "setgid(%d) failed : %s", gid, strerror(errno));
if (setuid(uid))
LOG_FATAL(LOGF_SysNetBSD, "setuid(%d) failed : %s", uid, strerror(errno));
DEBUG_LOG(LOGF_SysNetBSD, "Root dropped to uid %d gid %d", uid, gid);
UTI_DropRoot(uid, gid);
/* Check if we have write access to /dev/clockctl */
fd = open("/dev/clockctl", O_WRONLY);

1
sysincl.h
View file

@ -35,6 +35,7 @@
#include <fcntl.h>
#include <float.h>
#include <glob.h>
#include <grp.h>
#include <math.h>
#include <netdb.h>
#include <netinet/in.h>

20
util.c
View file

@ -1118,6 +1118,26 @@ UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid)
/* ================================================== */
void
UTI_DropRoot(uid_t uid, gid_t gid)
{
/* Drop supplementary groups */
if (setgroups(0, NULL))
LOG_FATAL(LOGF_Util, "setgroups() failed : %s", strerror(errno));
/* Set effective, saved and real group ID */
if (setgid(gid))
LOG_FATAL(LOGF_Util, "setgid(%d) failed : %s", gid, strerror(errno));
/* Set effective, saved and real user ID */
if (setuid(uid))
LOG_FATAL(LOGF_Util, "setuid(%d) failed : %s", uid, strerror(errno));
DEBUG_LOG(LOGF_Util, "Dropped root privileges: UID %d GID %d", uid, gid);
}
/* ================================================== */
#define DEV_URANDOM "/dev/urandom"
void

3
util.h
View file

@ -145,6 +145,9 @@ extern int UTI_CreateDirAndParents(const char *path, mode_t mode, uid_t uid, gid
permissions and its uid/gid must match the specified values. */
extern int UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid);
/* Set process user/group IDs and drop supplementary groups */
extern void UTI_DropRoot(uid_t uid, gid_t gid);
/* Fill buffer with random bytes */
extern void UTI_GetRandomBytes(void *buf, unsigned int len);