procstat: Allow querying the names of compartments of another process

lib/libprocstat/Symbol.map

@@ -51,4 +51,5 @@ FBSD_1.7 {
 	 procstat_get_revoker_epoch;
 	 procstat_get_revoker_state;
 	 procstat_getc18n;
+	 procstat_getcompartments;
 };

lib/libprocstat/libprocstat.3

@@ -1,6 +1,12 @@
+.\" Copyright (c) 2024 Capabilities Limited
 .\" Copyright (c) 2011 Sergey Kandaurov <[email protected]>
 .\" All rights reserved.
 .\"
+.\" This software was developed by SRI International, the University of
+.\" Cambridge Computer Laboratory (Department of Computer Science and
+.\" Technology), and Capabilities Limited under Defense Advanced Research
+.\" Projects Agency (DARPA) Contract No. FA8750-24-C-B047 ("DEC").
+.\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
@@ -22,7 +28,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 3, 2022
+.Dd December 5, 2024
 .Dt LIBPROCSTAT 3
 .Os
 .Sh NAME
@@ -47,6 +53,8 @@
 .Nm procstat_getargv ,
 .Nm procstat_getauxv ,
 .Nm procstat_getenvv ,
+.Nm procstat_getc18n ,
+.Nm procstat_getcompartments ,
 .Nm procstat_getfiles ,
 .Nm procstat_getgroups ,
 .Nm procstat_getkstack ,
@@ -67,6 +75,7 @@
 .In sys/param.h
 .In sys/queue.h
 .In sys/socket.h
+.In cheri/c18n.h
 .In libprocstat.h
 .Ft void
 .Fn procstat_close "struct procstat *procstat"
@@ -170,6 +179,19 @@
 .Fa "struct kinfo_proc *kp"
 .Fa "unsigned int *count"
 .Fc
+.Ft "int"
+.Fo procstat_getc18n
+.Fa "struct procstat *procstat"
+.Fa "struct kinfo_proc *kp"
+.Fa "struct rtld_c18n_stats *stats"
+.Fc
+.Ft "int"
+.Fo procstat_getcompartments
+.Fa "struct procstat *procstat"
+.Fa "struct kinfo_proc *kp"
+.Fa "struct cheri_c18n_compart *comparts"
+.Fa "u_int *ncompartsp"
+.Fc
 .Ft "char **"
 .Fo procstat_getenvv
 .Fa "struct procstat *procstat"
@@ -570,6 +592,28 @@ argument indicates an actual error message in case of failure.
 .It Li PS_FST_TYPE_SHM
 .Nm procstat_get_shm_info
 .El
+.Pp
+The
+.Fn procstat_getc18n
+function retrieves
+compartmentalization (\c
+.Xr c18n )
+statistics for a target process, including its number of intra-process
+compartments, instantiated trampolines, and other values.
+The
+.Fn procstat_getcompartments
+function retrieves a compartment list for target process.
+The
+.Fa comparts
+argument is a pointer to a caller-allocated array of
+.Ft struct cheri_c18n_compart
+entries of size
+.Fa *ncompartsp
+passed by reference.
+On return, the compartment list is terminated with a compartment ID of
+.Dv CHERI_C18N_COMPART_LAST .
+If a terminating entry is not found in the returned array, then there was
+insufficient space, and the caller should allocate a larger array and retry.
 .Sh SEE ALSO
 .Xr fstat 1 ,
 .Xr fuser 1 ,
@@ -583,6 +627,7 @@ argument indicates an actual error message in case of failure.
 .Xr sysctl 3 ,
 .Xr pts 4 ,
 .Xr core 5 ,
+.Xr c18n 7 ,
 .Xr vnode 9
 .Sh HISTORY
 The
@@ -595,6 +640,9 @@ The
 .Nm libprocstat
 library was written by
 .An Stanislav Sedov Aq Mt [email protected] .
+.Xr c18n 3 -related
+monitoring APIs were added by
+.An Robert N. M. Watson Aq Mt [email protected] .
 .Pp
 This manual page was written by
 .An Sergey Kandaurov Aq Mt [email protected] .

lib/libprocstat/libprocstat.c

@@ -1,11 +1,17 @@
 /*-
  * SPDX-License-Identifier: BSD-4-Clause
  *
+ * Copyright (c) 2024 Capabilities Limited
  * Copyright (c) 2017 Dell EMC
  * Copyright (c) 2009 Stanislav Sedov <[email protected]>
  * Copyright (c) 1988, 1993
  *      The Regents of the University of California.  All rights reserved.
  *
+ * This software was developed by SRI International, the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology), and Capabilities Limited under Defense Advanced Research
+ * Projects Agency (DARPA) Contract No. FA8750-24-C-B047 ("DEC").
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -399,6 +405,53 @@ procstat_getc18n(struct procstat *procstat, struct kinfo_proc *kp,
 	return (-1);
 }
 
+int
+procstat_getcompartments(struct procstat *procstat, struct kinfo_proc *kp,
+    struct cheri_c18n_compart *comparts, u_int *ncompartsp)
+{
+	int name[4];
+	size_t size;
+
+	if (comparts == NULL || ncompartsp == NULL)
+		goto out;
+
+	switch (procstat->type) {
+	case PROCSTAT_KVM:
+		warnx("kvm method is not supported");
+		goto out;
+
+	case PROCSTAT_SYSCTL:
+		break;
+
+	case PROCSTAT_CORE:
+		warnx("core method is not supported");
+		goto out;
+
+	default:
+		warnx("unknown access method: %d", procstat->type);
+		goto out;
+	}
+
+	name[0] = CTL_KERN;
+	name[1] = KERN_PROC;
+	name[2] = KERN_PROC_C18N_COMPARTS;
+	name[3] = kp->ki_pid;
+	size = *ncompartsp * sizeof(*comparts);
+	if (sysctl(name, nitems(name), comparts, &size, NULL, 0) != 0) {
+		if (errno != ESRCH && errno != EPERM && errno != ENOEXEC)
+			warn("sysctl(kern.proc.c18n_compartments)");
+		goto out;
+	}
+	if (size % sizeof(*comparts) != 0)
+		goto out;
+	*ncompartsp = size / sizeof(*comparts);
+	return (0);
+
+out:
+	*ncompartsp = 0;
+	return (-1);
+}
+
 struct filestat_list *
 procstat_getfiles(struct procstat *procstat, struct kinfo_proc *kp, int mmapped)
 {

lib/libprocstat/libprocstat.h

@@ -217,6 +217,9 @@ void	procstat_freevmmap(struct procstat *procstat,
 struct advlock_list	*procstat_getadvlock(struct procstat *procstat);
 int	procstat_getc18n(struct procstat *procstat, struct kinfo_proc *kp,
     struct rtld_c18n_stats *stats);
+int	procstat_getcompartments(struct procstat *procstat,
+    struct kinfo_proc *kp, struct cheri_c18n_compart *comparts,
+    u_int *ncomparts);
 struct filestat_list	*procstat_getfiles(struct procstat *procstat,
     struct kinfo_proc *kp, int mmapped);
 struct kinfo_proc	*procstat_getprocs(struct procstat *procstat,

usr.bin/procstat/Makefile

@@ -10,6 +10,7 @@ SRCS=	procstat.c		\
 	procstat_bin.c		\
 	procstat_c18n.c		\
 	procstat_cheri.c	\
+	procstat_compartments.c	\
 	procstat_cred.c		\
 	procstat_cs.c		\
 	procstat_files.c	\

usr.bin/procstat/procstat.1

@@ -176,6 +176,10 @@ Display CHERI-specific information about the process.
 If the
 .Fl v
 flag is passed then extra information is shown.
+.It Ar compartments
+Display information on
+.Xr c18n 7
+compartments within the process.
 .It Ar environment | Fl e
 Display environment variables for the process.
 .Pp
@@ -380,6 +384,21 @@ revoker initialized, epoch open
 .It closing
 revoker finishing an epoch
 .El
+.Ss Compartment List
+Display the list of
+.Xr c18n 7
+compartments within a process:
+.Pp
+.Bl -tag -width CNAME -compact
+.It PID
+process ID
+.It COMM
+command
+.It CID
+compartment ID
+.It CNAME
+compartment name
+.El
 .Ss Environment Variables
 Display the process ID, command, and environment variables:
 .Pp

usr.bin/procstat/procstat.c

@@ -97,6 +97,8 @@ static const struct procstat_cmd cmd_table[] = {
 	    PS_CMP_NORMAL },
 	{ "cheri", "cheri", "[-v]", &procstat_cheri, &cmdopt_verbose,
 	    PS_CMP_NORMAL },
+	{ "compartments", "compartments", NULL, &procstat_compartments,
+	    cmdopt_none, PS_CMP_NORMAL },
 	{ "cpuset", "cs", NULL, &procstat_cs, &cmdopt_cpuset, PS_CMP_NORMAL },
 	{ "cs", "cs", NULL, &procstat_cs, &cmdopt_cpuset, PS_CMP_NORMAL },
 	{ "credential", "credentials", NULL, &procstat_cred, &cmdopt_none,

usr.bin/procstat/procstat.h

@@ -62,6 +62,8 @@ void	procstat_basic(struct procstat *prstat, struct kinfo_proc *kipp);
 void	procstat_bin(struct procstat *prstat, struct kinfo_proc *kipp);
 void	procstat_c18n(struct procstat *prstat, struct kinfo_proc *kipp);
 void	procstat_cheri(struct procstat *prstat, struct kinfo_proc *kipp);
+void	procstat_compartments(struct procstat *procstat,
+	    struct kinfo_proc *kipp);
 void	procstat_cred(struct procstat *prstat, struct kinfo_proc *kipp);
 void	procstat_cs(struct procstat *prstat, struct kinfo_proc *kipp);
 void	procstat_env(struct procstat *prstat, struct kinfo_proc *kipp);