diff --git a/.gitignore b/.gitignore index 405b07ef4d..baa975d813 100644 --- a/.gitignore +++ b/.gitignore @@ -67,6 +67,7 @@ /systemd-debug-generator /systemd-delta /systemd-detect-virt +/systemd-dissect /systemd-escape /systemd-export /systemd-firstboot diff --git a/Makefile.am b/Makefile.am index c47a07a1f0..c6adf3a65c 100644 --- a/Makefile.am +++ b/Makefile.am @@ -404,6 +404,11 @@ rootlibexec_PROGRAMS = \ systemd-socket-proxyd \ systemd-update-done +if HAVE_BLKID +rootlibexec_PROGRAMS += \ + systemd-dissect +endif + if HAVE_UTMP rootlibexec_PROGRAMS += \ systemd-update-utmp @@ -3073,6 +3078,13 @@ systemd_notify_SOURCES = \ systemd_notify_LDADD = \ libsystemd-shared.la +# ------------------------------------------------------------------------------ +systemd_dissect_SOURCES = \ + src/dissect/dissect.c + +systemd_dissect_LDADD = \ + libsystemd-shared.la + # ------------------------------------------------------------------------------ systemd_path_SOURCES = \ src/path/path.c diff --git a/src/dissect/Makefile b/src/dissect/Makefile new file mode 120000 index 0000000000..d0b0e8e008 --- /dev/null +++ b/src/dissect/Makefile @@ -0,0 +1 @@ +../Makefile \ No newline at end of file diff --git a/src/dissect/dissect.c b/src/dissect/dissect.c new file mode 100644 index 0000000000..93ece05948 --- /dev/null +++ b/src/dissect/dissect.c @@ -0,0 +1,206 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd 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 2.1 of the License, or + (at your option) any later version. + + systemd 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 systemd; If not, see . +***/ + +#include +#include +#include + +#include "architecture.h" +#include "dissect-image.h" +#include "log.h" +#include "loop-util.h" +#include "string-util.h" +#include "util.h" + +static enum { + ACTION_DISSECT, + ACTION_MOUNT, +} arg_action = ACTION_DISSECT; +static const char *arg_image = NULL; +static const char *arg_path = NULL; +static bool arg_read_only = false; + +static void help(void) { + printf("%s [OPTIONS...] IMAGE\n" + "%s [OPTIONS...] --mount IMAGE PATH\n" + "Dissect a file system OS image.\n\n" + " -h --help Show this help\n" + " --version Show package version\n" + " -m --mount Mount the image to the specified directory\n" + " -r --read-only Mount read-only\n", + program_invocation_short_name, + program_invocation_short_name); +} + +static int parse_argv(int argc, char *argv[]) { + + enum { + ARG_VERSION = 0x100, + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "mount", no_argument, NULL, 'm' }, + { "read-only", no_argument, NULL, 'r' }, + {} + }; + + int c; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "hmr", options, NULL)) >= 0) { + + switch (c) { + + case 'h': + help(); + return 0; + + case ARG_VERSION: + return version(); + + case 'm': + arg_action = ACTION_MOUNT; + break; + + case 'r': + arg_read_only = true; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached("Unhandled option"); + } + + } + + switch (arg_action) { + + case ACTION_DISSECT: + if (optind + 1 != argc) { + log_error("Expected a file path as only argument."); + return -EINVAL; + } + + arg_image = argv[optind]; + arg_read_only = true; + break; + + case ACTION_MOUNT: + if (optind + 2 != argc) { + log_error("Expected a file path and mount point path as only arguments."); + return -EINVAL; + } + + arg_image = argv[optind]; + arg_path = argv[optind + 1]; + break; + + default: + assert_not_reached("Unknown action."); + } + + return 1; +} + +int main(int argc, char *argv[]) { + _cleanup_(loop_device_unrefp) LoopDevice *d = NULL; + _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL; + int r; + + log_parse_environment(); + log_open(); + + r = parse_argv(argc, argv); + if (r <= 0) + goto finish; + + r = loop_device_make_by_path(arg_image, arg_read_only ? O_RDONLY : O_RDWR, &d); + if (r < 0) { + log_error_errno(r, "Failed to set up loopback device: %m"); + goto finish; + } + + r = dissect_image(d->fd, &m); + if (r == -ENOPKG) { + log_error_errno(r, "Couldn't identify a suitable partition table or file system in %s.", arg_image); + goto finish; + } + if (r < 0) { + log_error_errno(r, "Failed to dissect image: %m"); + goto finish; + } + + switch (arg_action) { + + case ACTION_DISSECT: { + unsigned i; + + for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) { + DissectedPartition *p = m->partitions + i; + + if (!p->found) + continue; + + printf("Found %s '%s' partition", + p->rw ? "writable" : "read-only", + partition_designator_to_string(i)); + + if (p->fstype) + printf(" of type %s", p->fstype); + + if (p->architecture != _ARCHITECTURE_INVALID) + printf(" for %s", architecture_to_string(p->architecture)); + + if (p->partno >= 0) + printf(" on partition #%i", p->partno); + + if (p->node) + printf(" (%s)", p->node); + + putchar('\n'); + } + + break; + } + + case ACTION_MOUNT: + r = dissected_image_mount(m, arg_path, + (arg_read_only ? DISSECTED_IMAGE_READ_ONLY : 0) | + DISSECTED_IMAGE_DISCARD_ON_LOOP); + if (r < 0) { + log_error_errno(r, "Failed to mount image: %m"); + goto finish; + } + + loop_device_relinquish(d); + break; + + default: + assert_not_reached("Unknown action."); + } + +finish: + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} diff --git a/src/shared/loop-util.c b/src/shared/loop-util.c index 8be4dbf938..047e213634 100644 --- a/src/shared/loop-util.c +++ b/src/shared/loop-util.c @@ -129,7 +129,7 @@ LoopDevice* loop_device_unref(LoopDevice *d) { if (d->fd >= 0) { - if (d->nr >= 0) { + if (d->nr >= 0 && !d->relinquished) { if (ioctl(d->fd, LOOP_CLR_FD) < 0) log_debug_errno(errno, "Failed to clear loop device: %m"); @@ -138,7 +138,7 @@ LoopDevice* loop_device_unref(LoopDevice *d) { safe_close(d->fd); } - if (d->nr >= 0) { + if (d->nr >= 0 && !d->relinquished) { _cleanup_close_ int control = -1; control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); @@ -155,3 +155,12 @@ LoopDevice* loop_device_unref(LoopDevice *d) { return NULL; } + +void loop_device_relinquish(LoopDevice *d) { + assert(d); + + /* Don't attempt to clean up the loop device anymore from this point on. Leave the clean-ing up to the kernel + * itself, using the loop device "auto-clear" logic we already turned on when creating the device. */ + + d->relinquished = true; +} diff --git a/src/shared/loop-util.h b/src/shared/loop-util.h index 5c847c4ac3..45fead5f18 100644 --- a/src/shared/loop-util.h +++ b/src/shared/loop-util.h @@ -29,11 +29,13 @@ struct LoopDevice { int fd; int nr; char *node; + bool relinquished; }; int loop_device_make(int fd, int open_flags, LoopDevice **ret); int loop_device_make_by_path(const char *path, int open_flags, LoopDevice **ret); LoopDevice* loop_device_unref(LoopDevice *d); - DEFINE_TRIVIAL_CLEANUP_FUNC(LoopDevice*, loop_device_unref); + +void loop_device_relinquish(LoopDevice *d);