Add the public interfaces getpidprevcon(3) and getpidprevcon_raw(3), and
the utility getpidprevcon to gather the previous context before the last
exec of a given process.
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
libselinux/include/selinux/selinux.h | 5 ++++
libselinux/man/man3/getcon.3 | 9 +++++++
libselinux/man/man3/getpidprevcon.3 | 1 +
libselinux/man/man3/getpidprevcon_raw.3 | 1 +
libselinux/src/procattr.c | 18 ++++++++++++++
libselinux/utils/.gitignore | 1 +
libselinux/utils/getpidprevcon.c | 33 +++++++++++++++++++++++++
7 files changed, 68 insertions(+)
create mode 100644 libselinux/man/man3/getpidprevcon.3
create mode 100644 libselinux/man/man3/getpidprevcon_raw.3
create mode 100644 libselinux/utils/getpidprevcon.c
diff --git a/libselinux/include/selinux/selinux.h b/libselinux/include/selinux/selinux.h
index 47af9953..a0948853 100644
--- a/libselinux/include/selinux/selinux.h
+++ b/libselinux/include/selinux/selinux.h
@@ -54,6 +54,11 @@ extern int getpidcon_raw(pid_t pid, char ** con);
extern int getprevcon(char ** con);
extern int getprevcon_raw(char ** con);
+/* Get previous context (prior to last exec) of process identified by pid, and
+ set *con to refer to it. Caller must free via freecon. */
+extern int getpidprevcon(pid_t pid, char ** con);
+extern int getpidprevcon_raw(pid_t pid, char ** con);
+
/* Get exec context, and set *con to refer to it.
Sets *con to NULL if no exec context has been set, i.e. using default.
If non-NULL, caller must free via freecon. */
diff --git a/libselinux/man/man3/getcon.3 b/libselinux/man/man3/getcon.3
index e7e394f3..38da958b 100644
--- a/libselinux/man/man3/getcon.3
+++ b/libselinux/man/man3/getcon.3
@@ -23,6 +23,10 @@ setcon \- set current security context of a process
.sp
.BI "int getpidcon_raw(pid_t " pid ", char **" context );
.sp
+.BI "int getpidprevcon(pid_t " pid ", char **" context );
+.sp
+.BI "int getpidprevcon_raw(pid_t " pid ", char **" context );
+.sp
.BI "int getpeercon(int " fd ", char **" context );
.sp
.BI "int getpeercon_raw(int " fd ", char **" context );
@@ -50,6 +54,11 @@ same as getcon but gets the context before the last exec.
returns the process context for the specified PID, which must be free'd with
.BR freecon ().
+.TP
+.BR getpidprevcon ()
+returns the process context before the last exec for the specified PID, which must be free'd with
+.BR freecon ().
+
.TP
.BR getpeercon ()
retrieves the context of the peer socket, which must be free'd with
diff --git a/libselinux/man/man3/getpidprevcon.3 b/libselinux/man/man3/getpidprevcon.3
new file mode 100644
index 00000000..1210b5a0
--- /dev/null
+++ b/libselinux/man/man3/getpidprevcon.3
@@ -0,0 +1 @@
+.so man3/getcon.3
diff --git a/libselinux/man/man3/getpidprevcon_raw.3 b/libselinux/man/man3/getpidprevcon_raw.3
new file mode 100644
index 00000000..1210b5a0
--- /dev/null
+++ b/libselinux/man/man3/getpidprevcon_raw.3
@@ -0,0 +1 @@
+.so man3/getcon.3
diff --git a/libselinux/src/procattr.c b/libselinux/src/procattr.c
index 6f4cfb82..b7a93a2b 100644
--- a/libselinux/src/procattr.c
+++ b/libselinux/src/procattr.c
@@ -300,3 +300,21 @@ int getpidcon(pid_t pid, char **c)
}
return getprocattrcon(c, pid, "current", NULL);
}
+
+int getpidprevcon_raw(pid_t pid, char **c)
+{
+ if (pid <= 0) {
+ errno = EINVAL;
+ return -1;
+ }
+ return getprocattrcon_raw(c, pid, "prev", NULL);
+}
+
+int getpidprevcon(pid_t pid, char **c)
+{
+ if (pid <= 0) {
+ errno = EINVAL;
+ return -1;
+ }
+ return getprocattrcon(c, pid, "prev", NULL);
+}
diff --git a/libselinux/utils/.gitignore b/libselinux/utils/.gitignore
index 3ef34374..b19b94a8 100644
--- a/libselinux/utils/.gitignore
+++ b/libselinux/utils/.gitignore
@@ -9,6 +9,7 @@ getdefaultcon
getenforce
getfilecon
getpidcon
+getpidprevcon
getsebool
getseuser
matchpathcon
diff --git a/libselinux/utils/getpidprevcon.c b/libselinux/utils/getpidprevcon.c
new file mode 100644
index 00000000..662ad500
--- /dev/null
+++ b/libselinux/utils/getpidprevcon.c
@@ -0,0 +1,33 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <selinux/selinux.h>
+
+int main(int argc, char **argv)
+{
+ pid_t pid;
+ char *buf;
+ int rc;
+
+ if (argc != 2) {
+ fprintf(stderr, "usage: %s pid\n", argv[0]);
+ exit(1);
+ }
+
+ if (sscanf(argv[1], "%d", &pid) != 1) {
+ fprintf(stderr, "%s: invalid pid %s\n", argv[0], argv[1]);
+ exit(2);
+ }
+
+ rc = getpidprevcon(pid, &buf);
+ if (rc < 0) {
+ fprintf(stderr, "%s: getpidprevcon() failed: %s\n", argv[0], strerror(errno));
+ exit(3);
+ }
+
+ printf("%s\n", buf);
+ freecon(buf);
+ exit(EXIT_SUCCESS);
+}
--
2.39.0
