[OpenWrt-Devel,procd,2/4] service: allow setting a dedicated group id
diff mbox series

Message ID 20190411190111.11738-2-mhei@heimpold.de
State Accepted
Delegated to: Hans Dedecker
Headers show
Series
  • procd enhancements
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Commit Message

Michael Heimpold April 11, 2019, 7:01 p.m. UTC
Sometimes is desirable to run a process with a specific group id
instead of the default one which is derived from passwd entry.

However, we still want to initialize supplementary group ids
(including the default one), thus we have to store the specific
one in a dedicated structure element.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>
---
 service/instance.c | 25 ++++++++++++++++++++-----
 service/instance.h |  4 +++-
 2 files changed, 23 insertions(+), 6 deletions(-)

Patch
diff mbox series

diff --git a/service/instance.c b/service/instance.c
index d37d872..d8bd52e 100644
--- a/service/instance.c
+++ b/service/instance.c
@@ -50,6 +50,7 @@  enum {
 	INSTANCE_ATTR_WATCH,
 	INSTANCE_ATTR_ERROR,
 	INSTANCE_ATTR_USER,
+	INSTANCE_ATTR_GROUP,
 	INSTANCE_ATTR_STDOUT,
 	INSTANCE_ATTR_STDERR,
 	INSTANCE_ATTR_NO_NEW_PRIVS,
@@ -76,6 +77,7 @@  static const struct blobmsg_policy instance_attr[__INSTANCE_ATTR_MAX] = {
 	[INSTANCE_ATTR_WATCH] = { "watch", BLOBMSG_TYPE_ARRAY },
 	[INSTANCE_ATTR_ERROR] = { "error", BLOBMSG_TYPE_ARRAY },
 	[INSTANCE_ATTR_USER] = { "user", BLOBMSG_TYPE_STRING },
+	[INSTANCE_ATTR_GROUP] = { "group", BLOBMSG_TYPE_STRING },
 	[INSTANCE_ATTR_STDOUT] = { "stdout", BLOBMSG_TYPE_BOOL },
 	[INSTANCE_ATTR_STDERR] = { "stderr", BLOBMSG_TYPE_BOOL },
 	[INSTANCE_ATTR_NO_NEW_PRIVS] = { "no_new_privs", BLOBMSG_TYPE_BOOL },
@@ -364,12 +366,12 @@  instance_run(struct service_instance *in, int _stdout, int _stderr)
 		closefd(_stderr);
 	}
 
-	if (in->user && in->gid && initgroups(in->user, in->gid)) {
+	if (in->user && in->pw_gid && initgroups(in->user, in->pw_gid)) {
 		ERROR("failed to initgroups() for user %s: %m\n", in->user);
 		exit(127);
 	}
-	if (in->gid && setgid(in->gid)) {
-		ERROR("failed to set group id %d: %m\n", in->gid);
+	if (in->gr_gid && setgid(in->gr_gid)) {
+		ERROR("failed to set group id %d: %m\n", in->gr_gid);
 		exit(127);
 	}
 	if (in->uid && setuid(in->uid)) {
@@ -650,10 +652,13 @@  instance_config_changed(struct service_instance *in, struct service_instance *in
 	if (string_changed(in->user, in_new->user))
 		return true;
 
+	if (string_changed(in->group, in_new->group))
+		return true;
+
 	if (in->uid != in_new->uid)
 		return true;
 
-	if (in->gid != in_new->gid)
+	if (in->pw_gid != in_new->pw_gid)
 		return true;
 
 	if (string_changed(in->pidfile, in_new->pidfile))
@@ -909,7 +914,16 @@  instance_config_parse(struct service_instance *in)
 		if (p) {
 			in->user = strdup(user);
 			in->uid = p->pw_uid;
-			in->gid = p->pw_gid;
+			in->gr_gid = in->pw_gid = p->pw_gid;
+		}
+	}
+
+	if (tb[INSTANCE_ATTR_GROUP]) {
+		const char *group = blobmsg_get_string(tb[INSTANCE_ATTR_GROUP]);
+		struct group *p = getgrnam(group);
+		if (p) {
+			in->group = strdup(group);
+			in->gr_gid = p->gr_gid;
 		}
 	}
 
@@ -1038,6 +1052,7 @@  instance_free(struct service_instance *in)
 	instance_config_cleanup(in);
 	free(in->config);
 	free(in->user);
+	free(in->group);
 	free(in);
 }
 
diff --git a/service/instance.h b/service/instance.h
index 9300d32..42cc4be 100644
--- a/service/instance.h
+++ b/service/instance.h
@@ -44,7 +44,9 @@  struct service_instance {
 
 	char *user;
 	uid_t uid;
-	gid_t gid;
+	gid_t pw_gid;
+	char *group;
+	gid_t gr_gid;
 
 	bool halt;
 	bool restart;