Add new SCM type called SCM_CGROUP to send "cgroup_path" in SCM.
This is useful for journald (systemd logging daemon) to get additional context
with each log line received using UNIX socket.
Signed-off-by: Jan Kaluza <jkaluza@xxxxxxxxxx>
---
include/linux/socket.h | 1 +
include/net/af_unix.h | 1 +
include/net/scm.h | 15 +++++++++++++++
net/core/scm.c | 18 ++++++++++++++++++
net/unix/af_unix.c | 20 ++++++++++++++++++++
5 files changed, 55 insertions(+)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 6c7ace0..621fff1 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -133,6 +133,7 @@ static inline struct cmsghdr * cmsg_nxthdr (struct msghdr *__msg, struct cmsghdr
#define SCM_AUDIT 0x04 /* rw: struct uaudit */
#define SCM_PROCINFO 0x05 /* rw: comm + cmdline (NULL terminated
array of char *) */
+#define SCM_CGROUP 0x06 /* rw: cgroup path */
struct ucred {
__u32 pid;
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 05c7678..c49bf35 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -32,6 +32,7 @@ struct unix_skb_parms_scm {
unsigned int sessionid;
char *procinfo;
int procinfo_len;
+ char *cgroup_path;
};
struct unix_skb_parms {
diff --git a/include/net/scm.h b/include/net/scm.h
index 3346030..5398826 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -41,6 +41,7 @@ struct scm_cookie {
struct scm_creds creds; /* Skb credentials */
struct scm_audit audit; /* Skb audit */
struct scm_procinfo procinfo; /* Skb procinfo */
+ char *cgroup_path;
#ifdef CONFIG_SECURITY_NETWORK
u32 secid; /* Passed security ID */
#endif
@@ -52,6 +53,7 @@ extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie
extern void __scm_destroy(struct scm_cookie *scm);
extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
extern int scm_get_current_procinfo(char **procinfo);
+extern int scm_get_current_cgroup_path(char **cgroup_path);
#ifdef CONFIG_SECURITY_NETWORK
static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
@@ -86,6 +88,12 @@ static inline void scm_set_procinfo(struct scm_cookie *scm,
scm->procinfo.len = len;
}
+static inline void scm_set_cgroup_path(struct scm_cookie *scm,
+ char *cgroup_path)
+{
+ scm->cgroup_path = cgroup_path;
+}
+
static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
{
put_pid(scm->pid);
@@ -140,6 +148,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
security_release_secctx(secdata, seclen);
}
}
+
+ kfree(scm->cgroup_path);
+ scm->cgroup_path = NULL;
}
#else
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
@@ -172,6 +183,10 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
put_cmsg(msg, SOL_SOCKET, SCM_AUDIT, sizeof(uaudits), &uaudits);
put_cmsg(msg, SOL_SOCKET, SCM_PROCINFO, scm->procinfo.len,
scm->procinfo.procinfo);
+ if (scm->cgroup_path) {
+ put_cmsg(msg, SOL_SOCKET, SCM_CGROUP,
+ strlen(scm->cgroup_path), scm->cgroup_path);
+ }
}
scm_destroy_cred(scm);
diff --git a/net/core/scm.c b/net/core/scm.c
index 09ec044..2d408b9 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -404,3 +404,21 @@ out:
return res;
}
EXPORT_SYMBOL(scm_get_current_procinfo);
+
+int scm_get_current_cgroup_path(char **cgroup_path)
+{
+ int ret = 0;
+
+ *cgroup_path = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (!(*cgroup_path))
+ return -ENOMEM;
+
+ ret = task_cgroup_path(current, *cgroup_path, PATH_MAX);
+ if (ret < 0) {
+ kfree(*cgroup_path);
+ *cgroup_path = NULL;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(scm_get_current_cgroup_path);
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ab0be13..b638083 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1344,6 +1344,7 @@ static void unix_destruct_scm(struct sk_buff *skb)
if (UNIXCB(skb).scm) {
scm.procinfo.procinfo = UNIXSCM(skb).procinfo;
scm.procinfo.len = UNIXSCM(skb).procinfo_len;
+ scm.cgroup_path = UNIXSCM(skb).cgroup_path;
}
if (UNIXCB(skb).fp)
unix_detach_fds(&scm, skb);
@@ -1420,6 +1421,14 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
return -ENOMEM;
}
+ UNIXSCM(skb).cgroup_path = NULL;
+ if (scm->cgroup_path) {
+ UNIXSCM(skb).cgroup_path = kstrdup(scm->cgroup_path,
+ GFP_KERNEL);
+ if (!UNIXSCM(skb).cgroup_path)
+ return -ENOMEM;
+ }
+
skb->destructor = unix_destruct_scm;
return err;
}
@@ -1443,6 +1452,7 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
UNIXSCM(skb).sessionid = audit_get_sessionid(current);
UNIXSCM(skb).procinfo_len = scm_get_current_procinfo(
&UNIXSCM(skb).procinfo);
+ scm_get_current_cgroup_path(&UNIXSCM(skb).cgroup_path);
}
}
@@ -1849,6 +1859,11 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
GFP_KERNEL),
UNIXSCM(skb).procinfo_len);
}
+ if (UNIXSCM(skb).cgroup_path) {
+ scm_set_cgroup_path(siocb->scm,
+ kstrdup(UNIXSCM(skb).cgroup_path,
+ GFP_KERNEL));
+ }
}
unix_set_secdata(siocb->scm, skb);
@@ -2042,6 +2057,11 @@ again:
GFP_KERNEL),
UNIXSCM(skb).procinfo_len);
}
+ if (UNIXSCM(skb).cgroup_path) {
+ scm_set_cgroup_path(siocb->scm,
+ kstrdup(UNIXSCM(skb).cgroup_path,
+ GFP_KERNEL));
+ }
}
check_creds = 1;
}
--
1.8.3.1
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