[apparmor] [PATCH 2/6] utils: Initial implementation of aa-exec in C
Tyler Hicks
tyhicks at canonical.com
Tue Dec 15 20:55:57 UTC 2015
Create a simple aa-exec implementation, written in C, matching the
--help, --debug, --verbose, and --profile options present in the current
Perl implementation.
The build system is updated to honor the USE_SYSTEM make variable which
allows aa-exec to be linked against the system libapparmor rather than
the libapparmor built in-tree.
For now, the C based implementation is built as the aa-exec-c binary
until it is feature equivalent with the Perl version.
Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
---
utils/Makefile | 42 ++++++++++++++-
utils/aa_exec.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 206 insertions(+), 1 deletion(-)
create mode 100644 utils/aa_exec.c
diff --git a/utils/Makefile b/utils/Makefile
index 4762262..711626b 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -43,7 +43,46 @@ PYPREFIX=/usr
PYFLAKES=pyflakes
po/${NAME}.pot: ${TOOLS} ${PYMODULES}
- $(MAKE) -C po ${NAME}.pot NAME=${NAME} SOURCES="${TOOLS} ${PYMODULES}"
+ $(MAKE) -C po ${NAME}.pot NAME=${NAME} SOURCES="${TOOLS} ${PYMODULES} aa-exec.c"
+
+ifdef USE_SYSTEM
+ LIBAPPARMOR = $(shell if pkg-config --exists libapparmor ; then \
+ pkg-config --silence-errors --libs libapparmor ; \
+ elif ldconfig -p | grep -q libapparmor\.so$$ ; then \
+ echo -lapparmor ; \
+ fi )
+ ifeq ($(strip $(LIBAPPARMOR)),)
+ ERROR_MESSAGE = $(error ${nl}\
+************************************************************************${nl}\
+Unable to find libapparmor installed on this system; either${nl}\
+install libapparmor devel packages, set the LIBAPPARMOR variable${nl}\
+manually, or build against in-tree libapparmor.${nl}\
+************************************************************************${nl})
+ endif # LIBAPPARMOR not set
+ LDLIBS += $(LIBAPPARMOR)
+else # !USE_SYSTEM
+ # use in-tree versions
+ LIBAPPARMOR_SRC := ../libraries/libapparmor/
+ LIBAPPARMOR_INCLUDE = $(LIBAPPARMOR_SRC)/include
+ LIBAPPARMOR_PATH := $(LIBAPPARMOR_SRC)/src/.libs/
+ ifeq ($(realpath $(LIBAPPARMOR_PATH)/libapparmor.a),)
+ ERROR_MESSAGE = $(error ${nl}\
+************************************************************************${nl}\
+$(LIBAPPARMOR_PATH)/libapparmor.a is missing; either build against${nl}\
+the in-tree libapparmor by building it first and then trying again${nl}\
+(see the top-level README for help) or build against the system${nl}\
+libapparmor by adding USE_SYSTEM=1 to your make command.${nl}\
+************************************************************************${nl})
+ endif
+
+ CFLAGS += -L$(LIBAPPARMOR_PATH) -I$(LIBAPPARMOR_INCLUDE)
+ LDLIBS += -Wl,-Bstatic -lapparmor -Wl,-Bdynamic -lpthread
+endif # USE_SYSTEM
+
+CFLAGS += -g -O0 -Wall -Wstrict-prototypes
+
+aa-exec-c: aa_exec.c
+ ${CC} ${CFLAGS} ${LDFLAGS} $^ -o $@ ${LDLIBS}
.PHONY: install
install: ${MANPAGES} ${HTMLMANPAGES}
@@ -71,6 +110,7 @@ clean: pod_clean
rm -rf staging/ build/
rm -f apparmor/*.pyc apparmor/rule/*.pyc
rm -rf apparmor/__pycache__/ apparmor/rule/__pycache__/
+ rm -f aa-exec-c
# ${CAPABILITIES} is defined in common/Make.rules
.PHONY: check_severity_db
diff --git a/utils/aa_exec.c b/utils/aa_exec.c
new file mode 100644
index 0000000..12f54d1
--- /dev/null
+++ b/utils/aa_exec.c
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2015
+ * Canonical, Ltd. (All rights reserved)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, contact Novell, Inc. or Canonical
+ * Ltd.
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/apparmor.h>
+#include <unistd.h>
+
+static const char *opt_profile = NULL;
+static bool opt_debug = false;
+static bool opt_verbose = false;
+
+static void usage(const char *name, bool error)
+{
+ FILE *stream = stdout;
+ int status = EXIT_SUCCESS;
+
+ if (error) {
+ stream = stderr;
+ status = EXIT_FAILURE;
+ }
+
+ fprintf(stream,
+ "USAGE: %s [OPTIONS] <prog> <args>\n"
+ "\n"
+ "Confine <prog> with the specified PROFILE.\n"
+ "\n"
+ "OPTIONS:\n"
+ " -p PROFILE, --profile=PROFILE PROFILE to confine <prog> with\n"
+ " -d, --debug show messages with debugging information\n"
+ " -v, --verbose show messages with stats\n"
+ " -h, --help display this help\n"
+ "\n", name);
+ exit(status);
+}
+
+#define error(fmt, args...) _error("aa-exec: ERROR: " fmt "\n", ## args)
+static void _error(const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+ exit(EXIT_FAILURE);
+}
+
+#define debug(fmt, args...) _debug("aa-exec: DEBUG: " fmt "\n", ## args)
+static void _debug(const char *fmt, ...)
+{
+ va_list args;
+
+ if (!opt_debug)
+ return;
+
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+}
+
+#define verbose(fmt, args...) _verbose(fmt "\n", ## args)
+static void _verbose(const char *fmt, ...)
+{
+ va_list args;
+
+ if (!opt_verbose)
+ return;
+
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+}
+
+static void verbose_print_argv(char **argv)
+{
+ if (!opt_verbose)
+ return;
+
+ fprintf(stderr, "exec");
+ for (; *argv; argv++)
+ fprintf(stderr, " %s", *argv);
+ fprintf(stderr, "\n");
+}
+
+static char **parse_args(int argc, char **argv)
+{
+ int opt;
+ struct option long_opts[] = {
+ {"debug", no_argument, 0, 'd'},
+ {"help", no_argument, 0, 'h'},
+ {"profile", required_argument, 0, 'p'},
+ {"verbose", no_argument, 0, 'v'},
+ };
+
+ while ((opt = getopt_long(argc, argv, "+dhp:v", long_opts, NULL)) != -1) {
+ switch (opt) {
+ case 'd':
+ opt_debug = true;
+ break;
+ case 'h':
+ usage(argv[0], false);
+ break;
+ case 'p':
+ opt_profile = optarg;
+ break;
+ case 'v':
+ opt_verbose = true;
+ break;
+ default:
+ usage(argv[0], true);
+ break;
+ }
+ }
+
+ if (optind >= argc)
+ usage(argv[0], true);
+
+ return argv + optind;
+}
+
+int main(int argc, char **argv)
+{
+ int rc = 0;
+
+ argv = parse_args(argc, argv);
+
+ if (opt_profile) {
+ verbose("aa_change_onexec(\"%s\")", opt_profile);
+ rc = aa_change_onexec(opt_profile);
+ debug("%d = aa_change_onexec(\"%s\")", rc, opt_profile);
+ }
+
+ if (rc) {
+ if (errno == ENOENT || errno == EACCES) {
+ error("profile '%s' does not exist", opt_profile);
+ } else if (errno == EINVAL) {
+ error("AppArmor interface not available");
+ } else {
+ error("%m");
+ }
+ }
+
+ verbose_print_argv(argv);
+ execvp(argv[0], argv);
+ error("Failed to execute \"%s\": %m", argv[0]);
+}
--
2.5.0
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