[apparmor] [PATCH v2 09/42] split routines for loading binary policy into its own file

Tyler Hicks tyhicks at canonical.com
Tue Mar 24 19:52:10 UTC 2015


On 2015-03-06 15:48:25, Tyler Hicks wrote:
> From: John Johansen <john.johansen at canonical.com>
> 
> Signed-off-by: John Johansen <john.johansen at canonical.com>
> [tyhicks: Handle inverted return from find_subdomainfs_mountpoint()]
> [tyhicks: Link test progs to libapparmor to fix make check build fail]
> [tyhicks: Migrate from opendir() to open() for opening apparmorfs]
> [tyhicks: Make some of the split out functions static]
> Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
> ---

Re-reviewed this one and it still looks good.

Tyler

>  parser/Makefile           |  12 ++-
>  parser/kernel_interface.c | 206 ++++++++++++++++++++++++++++++++++++++++++++++
>  parser/kernel_interface.h |  25 ++++++
>  parser/lib.c              |   2 +-
>  parser/lib.h              |   2 +-
>  parser/parser_interface.c |  83 -------------------
>  parser/parser_main.c      |  24 +++---
>  7 files changed, 252 insertions(+), 102 deletions(-)
>  create mode 100644 parser/kernel_interface.c
>  create mode 100644 parser/kernel_interface.h
> 
> diff --git a/parser/Makefile b/parser/Makefile
> index 9175a30..9735ea4 100644
> --- a/parser/Makefile
> +++ b/parser/Makefile
> @@ -75,10 +75,10 @@ SRCS = parser_common.c parser_include.c parser_interface.c parser_lex.c \
>         parser_yacc.c parser_regex.c parser_variable.c parser_policy.c \
>         parser_alias.c common_optarg.c lib.c network.c \
>         mount.cc dbus.cc profile.cc rule.cc signal.cc ptrace.cc \
> -       af_rule.cc af_unix.cc features.c policy_cache.c
> +       af_rule.cc af_unix.cc features.c policy_cache.c kernel_interface.c
>  HDRS = parser.h parser_include.h immunix.h mount.h dbus.h lib.h profile.h \
>         rule.h common_optarg.h signal.h ptrace.h network.h af_rule.h af_unix.h \
> -       features.h policy_cache.h
> +       features.h policy_cache.h kernel_interface.h
>  TOOLS = apparmor_parser
>  
>  OBJECTS = $(patsubst %.cc, %.o, $(SRCS:.c=.o))
> @@ -119,6 +119,7 @@ TEST_OBJECTS = $(filter-out \
>  			policy_cache.o, ${OBJECTS}) \
>                 $(AAREOBJECTS)
>  TEST_LDFLAGS = $(AARE_LDFLAGS)
> +TEST_LDLIBS = $(AALIB)
>  
>  ifdef V
>    VERBOSE = 1
> @@ -242,6 +243,9 @@ features.o: features.c features.h parser.h libapparmor_re/apparmor_re.h
>  policy_cache.o: policy_cache.c policy_cache.h parser.h
>  	$(CXX) $(EXTRA_CFLAGS) -c -o $@ $<
>  
> +kernel_interface.o: kernel_interface.c kernel_interface.h
> +	$(CXX) $(EXTRA_CFLAGS) -c -o $@ $<
> +
>  lib.o: lib.c lib.h parser.h
>  	$(CXX) $(EXTRA_CFLAGS) -c -o $@ $<
>  
> @@ -287,9 +291,9 @@ cap_names.h: /usr/include/linux/capability.h
>  	echo "$(CAPABILITIES)" | LC_ALL=C sed -n -e "s/[ \\t]\\?CAP_\\([A-Z0-9_]\\+\\)/\{\"\\L\\1\", \\UCAP_\\1\},\\n/pg" > $@
>  
>  tst_lib: lib.c parser.h $(filter-out lib.o, ${TEST_OBJECTS})
> -	$(CXX) $(TEST_CFLAGS) -o $@ $< $(filter-out $(<:.c=.o), ${TEST_OBJECTS}) $(TEST_LDFLAGS)
> +	$(CXX) $(TEST_CFLAGS) -o $@ $< $(filter-out $(<:.c=.o), ${TEST_OBJECTS}) $(TEST_LDFLAGS) $(TEST_LDLIBS)
>  tst_%: parser_%.c parser.h $(filter-out parser_%.o, ${TEST_OBJECTS})
> -	$(CXX) $(TEST_CFLAGS) -o $@ $< $(filter-out $(<:.c=.o), ${TEST_OBJECTS}) $(TEST_LDFLAGS)
> +	$(CXX) $(TEST_CFLAGS) -o $@ $< $(filter-out $(<:.c=.o), ${TEST_OBJECTS}) $(TEST_LDFLAGS) $(TEST_LDLIBS)
>  
>  .SILENT: check
>  .PHONY: check
> diff --git a/parser/kernel_interface.c b/parser/kernel_interface.c
> new file mode 100644
> index 0000000..5585249
> --- /dev/null
> +++ b/parser/kernel_interface.c
> @@ -0,0 +1,206 @@
> +/*
> + *   Copyright (c) 2014
> + *   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 <fcntl.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <sys/apparmor.h>
> +#include <unistd.h>
> +
> +#include "kernel_interface.h"
> +#include "lib.h"
> +#include "parser.h"
> +
> +#define DEFAULT_APPARMORFS "/sys/kernel/security/apparmor"
> +
> +/**
> + * aa_find_iface_dir - find where the apparmor interface is located
> + * @dir - RETURNs: stored location of interface director
> + *
> + * Returns: 0 on success, -1 with errno set if there is an error
> + */
> +int aa_find_iface_dir(char **dir)
> +{
> +	if (aa_find_mountpoint(dir) == -1) {
> +		struct stat buf;
> +		if (stat(DEFAULT_APPARMORFS, &buf) == -1) {
> +			return -1;
> +		} else {
> +			*dir = strdup(DEFAULT_APPARMORFS);
> +			if (*dir == NULL)
> +				return -1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * open_iface_dir - open the apparmor interface dir
> + *
> + * Returns: opened file descriptor, or -1 with errno on error
> + */
> +static int open_iface_dir(void)
> +{
> +	autofree char *dir = NULL;
> +
> +	if (aa_find_iface_dir(&dir) == -1)
> +		return -1;
> +
> +	return open(dir, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
> +}
> +
> +
> +/* bleah the kernel should just loop and do multiple load, but to support
> + * older systems we need to do this
> + */
> +#define PROFILE_HEADER_SIZE
> +static char header_version[] = "\x04\x08\x00version";
> +
> +static const char *next_profile_buffer(const char *buffer, int size)
> +{
> +	const char *b = buffer;
> +
> +	for (; size - sizeof(header_version); b++, size--) {
> +		if (memcmp(b, header_version, sizeof(header_version)) == 0) {
> +			return b;
> +		}
> +	}
> +	return NULL;
> +}
> +
> +static int write_buffer(int fd, const char *buffer, int size, int set)
> +{
> +	const char *err_str = set ? "profile set" : "profile";
> +	int wsize = write(fd, buffer, size);
> +	if (wsize < 0) {
> +		PERROR(_("%s: Unable to write %s\n"), progname, err_str);
> +		return -1;
> +	} else if (wsize < size) {
> +		PERROR(_("%s: Unable to write %s\n"), progname, err_str);
> +		errno = EPROTO;
> +		return -1;
> +	}
> +	return 0;
> +}
> +
> +/**
> + * write_policy_buffer - load compiled policy into the kernel
> + * @fd: kernel iterface to write to
> + * @atomic: whether to load all policy in buffer atomically (true)
> + * @buffer: buffer of policy to load
> + * @size: the size of the data in the buffer
> + *
> + * Returns: 0 if the buffer loaded correctly
> + *         -1 if the load failed with errno set to the error
> + *
> + * @atomic should only be set to true if the kernel supports atomic profile
> + * set loads, otherwise only the 1st profile in the buffer will be loaded
> + * (older kernels only support loading one profile at a time).
> + */
> +static int write_policy_buffer(int fd, int atomic,
> +			       const char *buffer, size_t size)
> +{
> +	size_t bsize;
> +	int rc;
> +
> +	if (atomic) {
> +		rc = write_buffer(fd, buffer, size, true);
> +	} else {
> +		const char *b, *next;
> +
> +		rc = 0;	/* in case there are no profiles */
> +		for (b = buffer; b; b = next, size -= bsize) {
> +			next = next_profile_buffer(b + sizeof(header_version),
> +						   size);
> +			if (next)
> +				bsize = next - b;
> +			else
> +				bsize = size;
> +			if (write_buffer(fd, b, bsize, false) == -1)
> +				return -1;
> +		}
> +	}
> +
> +	if (rc)
> +		return -1;
> +
> +	return 0;
> +}
> +
> +/**
> + * open_option_iface - open the interface file for @option
> + * @aadir: apparmorfs dir
> + * @option: load command option
> + *
> + * Returns: fd to interface or -1 on error, with errno set.
> + */
> +static int open_option_iface(int aadir, int option)
> +{
> +	const char *name;
> +
> +	switch (option) {
> +	case OPTION_ADD:
> +		name = ".load";
> +		break;
> +	case OPTION_REPLACE:
> +		name = ".replace";
> +		break;
> +	case OPTION_REMOVE:
> +		name = ".remove";
> +		break;
> +	default:
> +		errno = EINVAL;
> +		return -1;
> +	}
> +
> +	return openat(aadir, name, O_WRONLY);
> +
> +	/* TODO: push up */
> +	/*
> +	if (fd < 0) {
> +		PERROR(_("Unable to open %s - %s\n"), filename,
> +		       strerror(errno));
> +		return -errno;
> +	}
> +	*/
> +}
> +
> +int aa_load_buffer(int option, char *buffer, int size)
> +{
> +	autoclose int dirfd = -1;
> +	autoclose int fd = -1;
> +
> +	/* TODO: push backup into caller */
> +	if (!kernel_load)
> +		return 0;
> +
> +	dirfd = open_iface_dir();
> +	if (dirfd == -1)
> +		return -1;
> +
> +	fd = open_option_iface(dirfd, option);
> +	if (fd == -1)
> +		return -1;
> +
> +	return write_policy_buffer(fd, kernel_supports_setload, buffer, size);
> +}
> diff --git a/parser/kernel_interface.h b/parser/kernel_interface.h
> new file mode 100644
> index 0000000..13e5996
> --- /dev/null
> +++ b/parser/kernel_interface.h
> @@ -0,0 +1,25 @@
> +/*
> + *   Copyright (c) 2014
> + *   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.
> + */
> +
> +#ifndef __AA_KERNEL_INTERFACE_H
> +#define __AA_KERNEL_INTERFACE_H
> +
> +int aa_find_iface_dir(char **dir);
> +int aa_load_buffer(int option, char *buffer, int size);
> +
> +#endif /* __AA_KERNEL_INTERFACE_H */
> diff --git a/parser/lib.c b/parser/lib.c
> index 5340971..9dbc154 100644
> --- a/parser/lib.c
> +++ b/parser/lib.c
> @@ -174,7 +174,7 @@ fail:
>   *
>   * Returns: true if an octal digit, else false
>   */
> -bool isodigit(char c)
> +int isodigit(char c)
>  {
>  	return (c >= '0' && c <= '7') ? true : false;
>  }
> diff --git a/parser/lib.h b/parser/lib.h
> index f047fd8..4cdf428 100644
> --- a/parser/lib.h
> +++ b/parser/lib.h
> @@ -13,7 +13,7 @@ void __autofclose(FILE **f);
>  int dirat_for_each(DIR *dir, const char *name, void *data,
>  		   int (* cb)(DIR *, const char *, struct stat *, void *));
>  
> -bool isodigit(char c);
> +int isodigit(char c);
>  long strntol(const char *str, const char **endptr, int base, long maxval,
>  	     size_t n);
>  int strn_escseq(const char **pos, const char *chrs, size_t n);
> diff --git a/parser/parser_interface.c b/parser/parser_interface.c
> index 7829b22..895b2bc 100644
> --- a/parser/parser_interface.c
> +++ b/parser/parser_interface.c
> @@ -604,86 +604,3 @@ exit:
>  	return error;
>  }
>  
> -/* bleah the kernel should just loop and do multiple load, but to support
> - * older systems we need to do this
> - */
> -#define PROFILE_HEADER_SIZE
> -static char header_version[] = "\x04\x08\x00version";
> -
> -static char *next_profile_buffer(char *buffer, int size)
> -{
> -	char *b = buffer;
> -
> -	for (; size - sizeof(header_version); b++, size--) {
> -		if (memcmp(b, header_version, sizeof(header_version)) == 0) {
> -			return b;
> -		}
> -	}
> -	return NULL;
> -}
> -
> -static int write_buffer(int fd, char *buffer, int size, bool set)
> -{
> -	const char *err_str = set ? "profile set" : "profile";
> -	int wsize = write(fd, buffer, size);
> -	if (wsize < 0) {
> -		PERROR(_("%s: Unable to write %s\n"), progname, err_str);
> -		return -errno;
> -	} else if (wsize < size) {
> -		PERROR(_("%s: Unable to write %s\n"), progname, err_str);
> -		return -EPROTO;
> -	}
> -	return 0;
> -}
> -
> -int sd_load_buffer(int option, char *buffer, int size)
> -{
> -	autoclose int fd = -1;
> -	int error, bsize;
> -	autofree char *filename = NULL;
> -
> -	/* TODO: push backup into caller */
> -	if (!kernel_load)
> -		return 0;
> -
> -	switch (option) {
> -	case OPTION_ADD:
> -		if (asprintf(&filename, "%s/.load", subdomainbase) == -1)
> -			return -ENOMEM;
> -		break;
> -	case OPTION_REPLACE:
> -		if (asprintf(&filename, "%s/.replace", subdomainbase) == -1)
> -			return -ENOMEM;
> -		break;
> -	default:
> -		return -EINVAL;
> -	}
> -
> -	fd = open(filename, O_WRONLY);
> -	if (fd < 0) {
> -		PERROR(_("Unable to open %s - %s\n"), filename,
> -		       strerror(errno));
> -		return -errno;
> -	}
> -
> -	if (kernel_supports_setload) {
> -		error = write_buffer(fd, buffer, size, true);
> -	} else {
> -		char *b, *next;
> -
> -		error = 0;	/* in case there are no profiles */
> -		for (b = buffer; b; b = next, size -= bsize) {
> -			next = next_profile_buffer(b + sizeof(header_version),
> -						   size);
> -			if (next)
> -				bsize = next - b;
> -			else
> -				bsize = size;
> -			error = write_buffer(fd, b, bsize, false);
> -			if (error)
> -				break;
> -		}
> -	}
> -
> -	return error;
> -}
> diff --git a/parser/parser_main.c b/parser/parser_main.c
> index 6850086..3358373 100644
> --- a/parser/parser_main.c
> +++ b/parser/parser_main.c
> @@ -41,6 +41,7 @@
>  
>  #include "lib.h"
>  #include "features.h"
> +#include "kernel_interface.h"
>  #include "parser.h"
>  #include "parser_version.h"
>  #include "parser_include.h"
> @@ -50,7 +51,6 @@
>  
>  #define OLD_MODULE_NAME "subdomain"
>  #define PROC_MODULES "/proc/modules"
> -#define DEFAULT_APPARMORFS "/sys/kernel/security/" MODULE_NAME
>  #define MATCH_FILE "/sys/kernel/security/" MODULE_NAME "/matching"
>  #define MOUNTED_FS "/proc/mounts"
>  #define AADFA "pattern=aadfa"
> @@ -513,18 +513,14 @@ static int process_config_file(const char *name)
>  
>  int find_subdomainfs_mountpoint(void)
>  {
> -	if (aa_find_mountpoint(&subdomainbase) == -1) {
> -		struct stat buf;
> -		if (stat(DEFAULT_APPARMORFS, &buf) == -1) {
> +	if (aa_find_iface_dir(&subdomainbase) == -1) {
>  		PERROR(_("Warning: unable to find a suitable fs in %s, is it "
>  			 "mounted?\nUse --subdomainfs to override.\n"),
>  		       MOUNTED_FS);
> -		} else {
> -			subdomainbase = strdup(DEFAULT_APPARMORFS);
> -		}
> +		return false;
>  	}
>  
> -	return (subdomainbase == NULL);
> +	return true;
>  }
>  
>  int have_enough_privilege(void)
> @@ -643,9 +639,11 @@ int process_binary(int option, const char *profilename)
>  			size += rsize;
>  	} while (rsize > 0);
>  
> -	if (rsize == 0)
> -		retval = sd_load_buffer(option, buffer, size);
> -	else
> +	if (rsize == 0) {
> +		retval = aa_load_buffer(option, buffer, size);
> +		if (retval == -1)
> +			retval = -errno;
> +	} else
>  		retval = rsize;
>  
>  	if (conf_verbose) {
> @@ -988,8 +986,8 @@ int main(int argc, char *argv[])
>  
>  	/* Check to make sure there is an interface to load policy */
>  	if (!(UNPRIVILEGED_OPS) && (subdomainbase == NULL) &&
> -	    (retval = find_subdomainfs_mountpoint())) {
> -		return retval;
> +	    !find_subdomainfs_mountpoint()) {
> +		return 1;
>  	}
>  
>  	if (!binary_input) parse_default_paths();
> -- 
> 2.1.4
> 
> 
> -- 
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> AppArmor at lists.ubuntu.com
> Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/apparmor
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