Allows other modules to use the same logic for uploading files. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- daemon/daemon.h | 3 +++ daemon/upload.c | 66 ++++++++++++++++++++++++++++++++------------------------- 2 files changed, 40 insertions(+), 29 deletions(-) diff --git a/daemon/daemon.h b/daemon/daemon.h index 5137e2c2a..75af5246e 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -261,6 +261,9 @@ extern int64_t ntfs_minimum_size (const char *device); extern int swap_set_uuid (const char *device, const char *uuid); extern int swap_set_label (const char *device, const char *label); +/*-- in upload.c --*/ +extern int upload_to_fd (int fd, const char *filename); + /* ordinary daemon functions use these to indicate errors * NB: you don't need to prefix the string with the current command, * it is added automatically by the client-side RPC stubs. diff --git a/daemon/upload.c b/daemon/upload.c index dc467d62b..c59fde295 100644 --- a/daemon/upload.c +++ b/daemon/upload.c @@ -56,19 +56,50 @@ write_cb (void *data_vp, const void *buf, size_t len) return 0; } +int +upload_to_fd (int fd, const char *filename) +{ + int r = 0, err = 0; + struct write_cb_data data = { .fd = fd, .written = 0 }; + + r = receive_file (write_cb, &data); + if (r == -1) { /* write error */ + err = errno; + ignore_value (cancel_receive ()); + errno = err; + reply_with_error ("write error: %s", filename); + close (fd); + return -1; + } + if (r == -2) { /* cancellation from library */ + /* This error is ignored by the library since it initiated the + * cancel. Nevertheless we must send an error reply here. + */ + reply_with_error ("file upload cancelled"); + close (fd); + return -1; + } + + if (close (fd) == -1) { + reply_with_perror ("close"); + return -1; + } + + return 0; +} + /* Has one FileIn parameter. */ static int upload (const char *filename, int flags, int64_t offset) { - struct write_cb_data data = { .written = 0 }; - int err, r, is_dev; + int err, is_dev, fd; is_dev = STRPREFIX (filename, "/dev/"); if (!is_dev) CHROOT_IN; - data.fd = open (filename, flags, 0666); + fd = open (filename, flags, 0666); if (!is_dev) CHROOT_OUT; - if (data.fd == -1) { + if (fd == -1) { err = errno; ignore_value (cancel_receive ()); errno = err; @@ -77,7 +108,7 @@ upload (const char *filename, int flags, int64_t offset) } if (offset) { - if (lseek (data.fd, offset, SEEK_SET) == -1) { + if (lseek (fd, offset, SEEK_SET) == -1) { err = errno; ignore_value (cancel_receive ()); errno = err; @@ -86,30 +117,7 @@ upload (const char *filename, int flags, int64_t offset) } } - r = receive_file (write_cb, &data); - if (r == -1) { /* write error */ - err = errno; - ignore_value (cancel_receive ()); - errno = err; - reply_with_error ("write error: %s", filename); - close (data.fd); - return -1; - } - if (r == -2) { /* cancellation from library */ - /* This error is ignored by the library since it initiated the - * cancel. Nevertheless we must send an error reply here. - */ - reply_with_error ("file upload cancelled"); - close (data.fd); - return -1; - } - - if (close (data.fd) == -1) { - reply_with_perror ("close: %s", filename); - return -1; - } - - return 0; + return upload_to_fd (fd, filename); } /* Has one FileIn parameter. */ -- 2.11.0

The yara_load API allows to load a set of Yara rules contained within a file on the host. Rules can be in binary format, as when compiled with yarac command, or in source code format. In the latter case, the rules will be first compiled and then loaded. Subsequent calls of the yara_load API will result in the discard of the previously loaded rules. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- daemon/Makefile.am | 1 + daemon/cleanups.c | 9 ++ daemon/cleanups.h | 2 + daemon/yara.c | 213 +++++++++++++++++++++++++++++++++++++++++++++ generator/Makefile.am | 3 + generator/actions.ml | 3 +- generator/actions_yara.ml | 48 ++++++++++ generator/actions_yara.mli | 21 +++++ generator/proc_nr.ml | 1 + lib/MAX_PROC_NR | 2 +- 10 files changed, 301 insertions(+), 2 deletions(-) create mode 100644 daemon/yara.c create mode 100644 generator/actions_yara.ml create mode 100644 generator/actions_yara.mli diff --git a/daemon/Makefile.am b/daemon/Makefile.am index ca01aeb4e..68f863bcd 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -170,6 +170,7 @@ guestfsd_SOURCES = \ wc.c \ xattr.c \ xfs.c \ + yara.c \ zero.c \ zerofree.c diff --git a/daemon/cleanups.c b/daemon/cleanups.c index 092e493d7..3102cf94b 100644 --- a/daemon/cleanups.c +++ b/daemon/cleanups.c @@ -62,6 +62,15 @@ cleanup_close (void *ptr) } void +cleanup_fclose (void *ptr) +{ + FILE *f = * (FILE **) ptr; + + if (f) + fclose (f); +} + +void cleanup_aug_close (void *ptr) { augeas *aug = * (augeas **) ptr; diff --git a/daemon/cleanups.h b/daemon/cleanups.h index 6746e2744..a791244cb 100644 --- a/daemon/cleanups.h +++ b/daemon/cleanups.h @@ -26,6 +26,7 @@ extern void cleanup_free (void *ptr); extern void cleanup_free_string_list (void *ptr); extern void cleanup_unlink_free (void *ptr); extern void cleanup_close (void *ptr); +extern void cleanup_fclose (void *ptr); extern void cleanup_aug_close (void *ptr); extern void cleanup_free_stringsbuf (void *ptr); @@ -35,6 +36,7 @@ extern void cleanup_free_stringsbuf (void *ptr); __attribute__((cleanup(cleanup_free_string_list))) #define CLEANUP_UNLINK_FREE __attribute__((cleanup(cleanup_unlink_free))) #define CLEANUP_CLOSE __attribute__((cleanup(cleanup_close))) +#define CLEANUP_FCLOSE __attribute__((cleanup(cleanup_fclose))) #define CLEANUP_AUG_CLOSE __attribute__((cleanup(cleanup_aug_close))) #define CLEANUP_FREE_STRINGSBUF __attribute__((cleanup(cleanup_free_stringsbuf))) #else diff --git a/daemon/yara.c b/daemon/yara.c new file mode 100644 index 000000000..3c80b1123 --- /dev/null +++ b/daemon/yara.c @@ -0,0 +1,213 @@ +/* libguestfs - the guestfsd daemon + * Copyright (C) 2016 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <config.h> + +#include <stdio.h> +#include <fcntl.h> +#include <stdlib.h> +#include <inttypes.h> +#include <string.h> +#include <unistd.h> +#include <stdbool.h> +#include <rpc/xdr.h> +#include <rpc/types.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include "daemon.h" +#include "actions.h" +#include "optgroups.h" +#include "guestfs_protocol.h" + +#ifdef HAVE_YARA + +#include <yara.h> + +#ifdef HAVE_ATTRIBUTE_CLEANUP +#define CLEANUP_DESTROY_YARA_COMPILER \ + __attribute__((cleanup(cleanup_destroy_yara_compiler))) +#else +#define CLEANUP_DESTROY_YARA_COMPILER +#endif + +struct write_callback_data { + int fd; + uint64_t written; +}; + +/* Yara compiled rules. */ +static YR_RULES *rules = NULL; +static bool initialized = false; + +static int compile_rules_file (const char *); +static void compile_error_callback (int, const char *, int, const char *, void *); +static void cleanup_destroy_yara_compiler (void *ptr); + +/* Has one FileIn parameter. + * Takes optional arguments, consult optargs_bitmask. + */ +int +do_yara_load (void) +{ + int r = 0; + CLEANUP_CLOSE int fd = -1; + char tmpfile[] = "/tmp/yaraXXXXXX"; + + fd = mkstemp (tmpfile); + if (fd == -1) { + reply_with_perror ("mkstemp"); + return -1; + } + + r = upload_to_fd (fd, tmpfile); + if (r == -1) { + unlink (tmpfile); + return -1; + } + + /* Initialize yara only once. */ + if (!initialized) { + r = yr_initialize (); + if (r != ERROR_SUCCESS) { + reply_with_error ("failed initializing yara"); + unlink (tmpfile); + return -1; + } + + initialized = true; + } + + /* Destroy previously loaded rules. */ + if (rules != NULL) { + yr_rules_destroy (rules); + rules = NULL; + } + + /* Try to load the rules as compiled. + * If their are in source code format, compile them first. + */ + r = yr_rules_load (tmpfile, &rules); + if (r == ERROR_INVALID_FILE) + r = compile_rules_file (tmpfile); + + unlink (tmpfile); + + return (r == ERROR_SUCCESS) ? 0 : -1; +} + +/* Compile source code rules and load them. + * Return ERROR_SUCCESS on success, Yara error code type on error. + */ +static int +compile_rules_file (const char *rules_path) +{ + int ret = 0; + CLEANUP_FCLOSE FILE *rule_file = NULL; + CLEANUP_DESTROY_YARA_COMPILER YR_COMPILER *compiler = NULL; + + ret = yr_compiler_create (&compiler); + if (ret != ERROR_SUCCESS) { + reply_with_error ("yr_compiler_create"); + return ret; + } + + yr_compiler_set_callback (compiler, compile_error_callback, NULL); + + rule_file = fopen (rules_path, "r"); + if (rule_file == NULL) { + reply_with_error ("unable to open rules file"); + ret = ERROR_COULD_NOT_OPEN_FILE; + goto err; + } + + ret = yr_compiler_add_file (compiler, rule_file, NULL, NULL); + if (ret > 0) + goto err; + + ret = yr_compiler_get_rules (compiler, &rules); + if (ret == ERROR_INSUFICIENT_MEMORY) { + errno = ENOMEM; + reply_with_perror ("yr_compiler_get_rules"); + } + + err: +#ifndef HAVE_ATTRIBUTE_CLEANUP + yr_compiler_destroy (compiler); +#endif + + return ret; +} + +/* Yara compilation error callback. + * Reports back the compilation error message. + * Prints compilation warnings if verbose. + */ +static void +compile_error_callback (int level, const char *name, int line, + const char *message, void *data) +{ + if (level == YARA_ERROR_LEVEL_ERROR) + reply_with_error ("Yara error (line %d): %s", line, message); + else if (verbose) + fprintf (stderr, "Yara warning (line %d): %s\n", line, message); +} + +/* Clean up yara handle on daemon exit. */ +void yara_finalize (void) __attribute__((destructor)); + +void +yara_finalize (void) +{ + int r = 0; + + if (!initialized) + return; + + if (rules != NULL) { + yr_rules_destroy (rules); + rules = NULL; + } + + r = yr_finalize (); + if (r != ERROR_SUCCESS) + perror ("yr_finalize"); + + initialized = false; +} + +static void +cleanup_destroy_yara_compiler (void *ptr) +{ + YR_COMPILER *compiler = * (YR_COMPILER **) ptr; + + if (compiler != NULL) + yr_compiler_destroy (compiler); +} + +int +optgroup_libyara_available (void) +{ + return 1; +} + +#else /* !HAVE_YARA */ + +OPTGROUP_LIBYARA_NOT_AVAILABLE + +#endif /* !HAVE_YARA */ diff --git a/generator/Makefile.am b/generator/Makefile.am index 31989cd4a..81b49cab1 100644 --- a/generator/Makefile.am +++ b/generator/Makefile.am @@ -45,6 +45,8 @@ sources = \ actions_tsk.mli \ authors.ml \ authors.mli \ + actions_yara.ml \ + actions_yara.mli \ bindtests.ml \ bindtests.mli \ c.ml \ @@ -132,6 +134,7 @@ objects = \ actions_properties.cmo \ actions_properties_deprecated.cmo \ actions_tsk.cmo \ + actions_yara.cmo \ actions.cmo \ structs.cmo \ fish_commands.cmo \ diff --git a/generator/actions.ml b/generator/actions.ml index a04fdc0f9..6e11d99c3 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -50,7 +50,8 @@ let daemon_functions = Actions_core_deprecated.daemon_functions @ Actions_debug.daemon_functions @ Actions_hivex.daemon_functions @ - Actions_tsk.daemon_functions + Actions_tsk.daemon_functions @ + Actions_yara.daemon_functions (* Some post-processing of the basic lists of actions. *) diff --git a/generator/actions_yara.ml b/generator/actions_yara.ml new file mode 100644 index 000000000..c38f68eb0 --- /dev/null +++ b/generator/actions_yara.ml @@ -0,0 +1,48 @@ +(* libguestfs + * Copyright (C) 2009-2017 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + *) + +(* Please read generator/README first. *) + +open Types + +(* Yara APIs. *) + +let daemon_functions = [ + { defaults with + name = "yara_load"; added = (1, 37, 12); + style = RErr, [FileIn "filename"], []; + progress = true; cancellable = true; + optional = Some "libyara"; + shortdesc = "load yara rules within libguestfs"; + longdesc = "\ +Upload a set of Yara rules from local file F<filename>. + +Yara rules allow to categorize files based on textual or binary patterns +within their content. +See C<guestfs_yara_scan> to see how to scan files with the loaded rules. + +Rules can be in binary format, as when compiled with yarac command, or +in source code format. In the latter case, the rules will be first +compiled and then loaded. + +Rules in source code format cannot include external files. In such cases, +it is recommended to compile them first. + +Previously loaded rules will be destroyed." }; + +] diff --git a/generator/actions_yara.mli b/generator/actions_yara.mli new file mode 100644 index 000000000..23eefe068 --- /dev/null +++ b/generator/actions_yara.mli @@ -0,0 +1,21 @@ +(* libguestfs + * Copyright (C) 2009-2017 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + *) + +(* Please read generator/README first. *) + +val daemon_functions : Types.action list diff --git a/generator/proc_nr.ml b/generator/proc_nr.ml index b3be31996..d50cc9efa 100644 --- a/generator/proc_nr.ml +++ b/generator/proc_nr.ml @@ -479,6 +479,7 @@ let proc_nr = [ 469, "aug_transform"; 470, "internal_find_inode"; 471, "mksquashfs"; +472, "yara_load"; ] (* End of list. If adding a new entry, add it at the end of the list diff --git a/lib/MAX_PROC_NR b/lib/MAX_PROC_NR index c305aa5ae..68cfb10d1 100644 --- a/lib/MAX_PROC_NR +++ b/lib/MAX_PROC_NR @@ -1 +1 @@ -471 +472 -- 2.11.0

The internal_yara_scan runs the Yara engine with the previously loaded rules against the given file. For each rule matching against the scanned file, a struct containing the file name and the rule identifier is returned. The gathered list of yara_detection structs is serialised into XDR format and written to a file. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- daemon/yara.c | 86 ++++++++++++++++++++++++++++++++ generator/actions_yara.ml | 8 +++ generator/proc_nr.ml | 1 + generator/structs.ml | 9 ++++ gobject/Makefile.inc | 2 + java/Makefile.inc | 1 + java/com/redhat/et/libguestfs/.gitignore | 1 + lib/MAX_PROC_NR | 2 +- 8 files changed, 109 insertions(+), 1 deletion(-) diff --git a/daemon/yara.c b/daemon/yara.c index 78e367f23..cab008a03 100644 --- a/daemon/yara.c +++ b/daemon/yara.c @@ -58,6 +58,8 @@ static bool initialized = false; static int compile_rules_file (const char *); static void compile_error_callback (int, const char *, int, const char *, void *); static void cleanup_destroy_yara_compiler (void *ptr); +static int yara_rules_callback (int , void *, void *); +static int send_detection_info (const char *, YR_RULE *); /* Has one FileIn parameter. * Takes optional arguments, consult optargs_bitmask. @@ -125,6 +127,38 @@ do_yara_destroy (void) return 0; } +/* Has one FileOut parameter. */ +int +do_internal_yara_scan (const char *path) +{ + int r = 0; + CLEANUP_CLOSE int fd = -1; + + if (rules == NULL) { + reply_with_error ("no yara rules loaded"); + return -1; + } + + CHROOT_IN; + fd = open (path, O_RDONLY|O_CLOEXEC); + CHROOT_OUT; + + if (fd < 0) { + reply_with_perror ("%s", path); + return -1; + } + + reply (NULL, NULL); /* Reply message. */ + + r = yr_rules_scan_fd (rules, fd, 0, yara_rules_callback, (void *) path, 0); + if (r == ERROR_SUCCESS) + r = send_file_end (0); /* File transfer end. */ + else + send_file_end (1); /* Cancel file transfer. */ + + return 0; +} + /* Compile source code rules and load them. * Return ERROR_SUCCESS on success, Yara error code type on error. */ @@ -182,6 +216,58 @@ compile_error_callback (int level, const char *name, int line, fprintf (stderr, "Yara warning (line %d): %s\n", line, message); } +/* Yara scan callback, called by yr_rules_scan_file. + * Return 0 on success, -1 on error. + */ +static int +yara_rules_callback (int code, void *message, void *data) +{ + int ret = 0; + + if (code == CALLBACK_MSG_RULE_MATCHING) + ret = send_detection_info ((const char *)data, (YR_RULE *) message); + + return (ret == 0) ? CALLBACK_CONTINUE : CALLBACK_ERROR; +} + +/* Serialize file path and rule name and send it out. + * Return 0 on success, -1 on error. + */ +static int +send_detection_info (const char *name, YR_RULE *rule) +{ + XDR xdr; + int r = 0; + size_t len = 0; + CLEANUP_FREE char *buf = NULL; + struct guestfs_int_yara_detection detection; + + detection.yara_name = (char *) name; + detection.yara_rule = (char *) rule->identifier; + + /* Serialize detection struct. */ + buf = malloc (GUESTFS_MAX_CHUNK_SIZE); + if (buf == NULL) { + perror ("malloc"); + return -1; + } + + xdrmem_create (&xdr, buf, GUESTFS_MAX_CHUNK_SIZE, XDR_ENCODE); + + r = xdr_guestfs_int_yara_detection (&xdr, &detection); + if (r == 0) { + perror ("xdr_guestfs_int_yara_detection"); + return -1; + } + + len = xdr_getpos (&xdr); + + xdr_destroy (&xdr); + + /* Send serialised yara_detection out. */ + return send_file_write (buf, len); +} + /* Clean up yara handle on daemon exit. */ void yara_finalize (void) __attribute__((destructor)); diff --git a/generator/actions_yara.ml b/generator/actions_yara.ml index 59c571b9e..1f7decdd4 100644 --- a/generator/actions_yara.ml +++ b/generator/actions_yara.ml @@ -53,4 +53,12 @@ Previously loaded rules will be destroyed." }; longdesc = "\ Destroy previously loaded Yara rules in order to free libguestfs resources." }; + { defaults with + name = "internal_yara_scan"; added = (1, 37, 12); + style = RErr, [Pathname "path"; FileOut "filename"], []; + visibility = VInternal; + optional = Some "libyara"; + shortdesc = "scan a file with the loaded yara rules"; + longdesc = "Internal function for yara_scan." }; + ] diff --git a/generator/proc_nr.ml b/generator/proc_nr.ml index d471b1a83..c7619638a 100644 --- a/generator/proc_nr.ml +++ b/generator/proc_nr.ml @@ -481,6 +481,7 @@ let proc_nr = [ 471, "mksquashfs"; 472, "yara_load"; 473, "yara_destroy"; +474, "internal_yara_scan"; ] (* End of list. If adding a new entry, add it at the end of the list diff --git a/generator/structs.ml b/generator/structs.ml index c1c9b668e..834fa9c54 100644 --- a/generator/structs.ml +++ b/generator/structs.ml @@ -469,6 +469,15 @@ let structs = [ ]; s_camel_name = "TSKDirent" }; + (* Yara detection information. *) + { defaults with + s_name = "yara_detection"; + s_cols = [ + "yara_name", FString; + "yara_rule", FString; + ]; + s_camel_name = "YaraDetection" }; + ] (* end of structs *) let lookup_struct name = diff --git a/gobject/Makefile.inc b/gobject/Makefile.inc index 8fa8599d3..a6dcba022 100644 --- a/gobject/Makefile.inc +++ b/gobject/Makefile.inc @@ -49,6 +49,7 @@ guestfs_gobject_headers= \ include/guestfs-gobject/struct-version.h \ include/guestfs-gobject/struct-xattr.h \ include/guestfs-gobject/struct-xfsinfo.h \ + include/guestfs-gobject/struct-yara_detection.h \ include/guestfs-gobject/optargs-add_domain.h \ include/guestfs-gobject/optargs-add_drive.h \ include/guestfs-gobject/optargs-add_drive_scratch.h \ @@ -141,6 +142,7 @@ guestfs_gobject_sources= \ src/struct-version.c \ src/struct-xattr.c \ src/struct-xfsinfo.c \ + src/struct-yara_detection.c \ src/optargs-add_domain.c \ src/optargs-add_drive.c \ src/optargs-add_drive_scratch.c \ diff --git a/java/Makefile.inc b/java/Makefile.inc index b0ddb5c3d..3a202cee0 100644 --- a/java/Makefile.inc +++ b/java/Makefile.inc @@ -46,4 +46,5 @@ java_built_sources = \ com/redhat/et/libguestfs/Version.java \ com/redhat/et/libguestfs/XAttr.java \ com/redhat/et/libguestfs/XFSInfo.java \ + com/redhat/et/libguestfs/YaraDetection.java \ com/redhat/et/libguestfs/GuestFS.java diff --git a/java/com/redhat/et/libguestfs/.gitignore b/java/com/redhat/et/libguestfs/.gitignore index 89d923949..bc03cb965 100644 --- a/java/com/redhat/et/libguestfs/.gitignore +++ b/java/com/redhat/et/libguestfs/.gitignore @@ -23,3 +23,4 @@ VG.java Version.java XAttr.java XFSInfo.java +YaraDetection.java diff --git a/lib/MAX_PROC_NR b/lib/MAX_PROC_NR index 8410b8b89..5f3bb9813 100644 --- a/lib/MAX_PROC_NR +++ b/lib/MAX_PROC_NR @@ -1 +1 @@ -473 +474 -- 2.11.0

The yara_scan API parses the file generated by the daemon counterpart function and returns the list of yara_detection structs to the user. It writes the daemon's command output on a temporary file and parses it, deserialising the XDR formatted yara_detection structs. It returns to the caller the list of yara_detection structs generated by the internal_yara_scan command. Signed-off-by: Matteo Cafasso <noxdafox(a)gmail.com&gt; --- generator/actions.ml | 3 +- generator/actions_yara.ml | 28 ++++++++++ generator/actions_yara.mli | 1 + lib/Makefile.am | 1 + lib/yara.c | 132 +++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 164 insertions(+), 1 deletion(-) create mode 100644 lib/yara.c diff --git a/generator/actions.ml b/generator/actions.ml index 6e11d99c3..2722f3dcd 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -38,7 +38,8 @@ let non_daemon_functions = Actions_inspection_deprecated.non_daemon_functions @ Actions_properties.non_daemon_functions @ Actions_properties_deprecated.non_daemon_functions @ - Actions_tsk.non_daemon_functions + Actions_tsk.non_daemon_functions @ + Actions_yara.non_daemon_functions (* daemon_functions are any functions which cause some action * to take place in the daemon. diff --git a/generator/actions_yara.ml b/generator/actions_yara.ml index 1f7decdd4..5afbd47e9 100644 --- a/generator/actions_yara.ml +++ b/generator/actions_yara.ml @@ -22,6 +22,34 @@ open Types (* Yara APIs. *) +let non_daemon_functions = [ + { defaults with + name = "yara_scan"; added = (1, 37, 12); + style = RStructList ("detections", "yara_detection"), [Pathname "path"], []; + optional = Some "libyara"; + progress = true; cancellable = true; + shortdesc = "scan a file with the loaded yara rules"; + longdesc = "\ +Scan a file with the previously loaded Yara rules. + +For each matching rule, a C<yara_detection> structure is returned. + +The C<yara_detection> structure contains the following fields. + +=over 4 + +=item C<yara_name> + +Path of the file matching a Yara rule. + +=item C<yara_rule> + +Identifier of the Yara rule which matched against the given file. + +=back" }; + +] + let daemon_functions = [ { defaults with name = "yara_load"; added = (1, 37, 12); diff --git a/generator/actions_yara.mli b/generator/actions_yara.mli index 23eefe068..06b8116c4 100644 --- a/generator/actions_yara.mli +++ b/generator/actions_yara.mli @@ -18,4 +18,5 @@ (* Please read generator/README first. *) +val non_daemon_functions : Types.action list val daemon_functions : Types.action list diff --git a/lib/Makefile.am b/lib/Makefile.am index 063706f8f..fc55c2dcf 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -127,6 +127,7 @@ libguestfs_la_SOURCES = \ wait.c \ whole-file.c \ version.c \ + yara.c \ libguestfs.syms libguestfs_la_CPPFLAGS = \ diff --git a/lib/yara.c b/lib/yara.c new file mode 100644 index 000000000..f4a6f5833 --- /dev/null +++ b/lib/yara.c @@ -0,0 +1,132 @@ +/* libguestfs + * Copyright (C) 2016 Red Hat Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <string.h> +#include <rpc/xdr.h> +#include <rpc/types.h> + +#include "guestfs.h" +#include "guestfs_protocol.h" +#include "guestfs-internal.h" +#include "guestfs-internal-all.h" +#include "guestfs-internal-actions.h" + +static struct guestfs_yara_detection_list *parse_yara_detection_file (guestfs_h *, const char *); +static int deserialise_yara_detection_list (guestfs_h *, FILE *, struct guestfs_yara_detection_list *); + +struct guestfs_yara_detection_list * +guestfs_impl_yara_scan (guestfs_h *g, const char *path) +{ + int r = 0; + CLEANUP_UNLINK_FREE char *tmpfile = NULL; + + tmpfile = guestfs_int_make_temp_path (g, "yara_scan"); + if (tmpfile == NULL) + return NULL; + + r = guestfs_internal_yara_scan (g, path, tmpfile); + if (r == -1) + return NULL; + + return parse_yara_detection_file (g, tmpfile); /* caller frees */ +} + +/* Parse the file content and return detections list. + * Return a list of yara_detection on success, NULL on error. + */ +static struct guestfs_yara_detection_list * +parse_yara_detection_file (guestfs_h *g, const char *tmpfile) +{ + int r = 0; + CLEANUP_FCLOSE FILE *fp = NULL; + struct guestfs_yara_detection_list *detections = NULL; + + fp = fopen (tmpfile, "r"); + if (fp == NULL) { + perrorf (g, "fopen: %s", tmpfile); + return NULL; + } + + /* Initialise results array. */ + detections = safe_malloc (g, sizeof (*detections)); + detections->len = 8; + detections->val = safe_malloc (g, detections->len * + sizeof (*detections->val)); + + /* Deserialise buffer into detection list. */ + r = deserialise_yara_detection_list (g, fp, detections); + if (r == -1) { + guestfs_free_yara_detection_list (detections); + perrorf (g, "deserialise_yara_detection_list"); + return NULL; + } + + return detections; +} + +/* Deserialise the file content and populate the detection list. + * Return the number of deserialised detections, -1 on error. + */ +static int +deserialise_yara_detection_list (guestfs_h *g, FILE *fp, + struct guestfs_yara_detection_list *detections) +{ + XDR xdr; + int r = 0; + uint32_t index = 0; + struct stat statbuf; + + r = fstat (fileno(fp), &statbuf); + if (r == -1) { + perrorf (g, "fstat"); + return -1; + } + + xdrstdio_create (&xdr, fp, XDR_DECODE); + + for (index = 0; xdr_getpos (&xdr) < statbuf.st_size; index++) { + if (index == detections->len) { + detections->len = 2 * detections->len; + detections->val = safe_realloc (g, detections->val, + detections->len * + sizeof (*detections->val)); + } + + /* Clear the entry so xdr logic will allocate necessary memory. */ + memset (&detections->val[index], 0, sizeof (*detections->val)); + r = xdr_guestfs_int_yara_detection (&xdr, (guestfs_int_yara_detection *) + &detections->val[index]); + if (r == 0) { + perrorf (g, "xdr_guestfs_int_yara_detection"); + break; + } + } + + xdr_destroy (&xdr); + detections->len = index; + + return r ? 0 : -1; +} -- 2.11.0