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Diffstat (limited to 'src/main/trigproc.c')
| -rw-r--r-- | src/main/trigproc.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/src/main/trigproc.c b/src/main/trigproc.c new file mode 100644 index 0000000..125eb02 --- /dev/null +++ b/src/main/trigproc.c @@ -0,0 +1,576 @@ +/* + * dpkg - main program for package management + * trigproc.c - trigger processing + * + * Copyright © 2007 Canonical Ltd + * written by Ian Jackson <ijackson@chiark.greenend.org.uk> + * Copyright © 2008-2014 Guillem Jover <guillem@debian.org> + * + * This 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 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, see <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <compat.h> + +#include <sys/stat.h> + +#include <fcntl.h> +#include <stdlib.h> + +#include <dpkg/i18n.h> +#include <dpkg/dpkg.h> +#include <dpkg/dpkg-db.h> +#include <dpkg/pkg.h> +#include <dpkg/pkg-queue.h> +#include <dpkg/db-ctrl.h> +#include <dpkg/db-fsys.h> +#include <dpkg/triglib.h> + +#include "main.h" + +/* + * Trigger processing algorithms: + * + * + * There is a separate queue (‘deferred trigproc list’) for triggers + * ‘relevant’ to what we just did; when we find something triggered ‘now’ + * we add it to that queue (unless --no-triggers). + * + * + * We want to prefer configuring packages where possible to doing trigger + * processing, although it would be better to prefer trigger processing + * to cycle-breaking we need to do the latter first or we might generate + * artificial trigger cycles, but we always want to prefer trigger + * processing to dependency forcing. This is achieved as follows: + * + * Each time during configure processing where a package D is blocked by + * only (ie Depends unsatisfied but would be satisfied by) a t-awaiter W + * we make a note of (one of) W's t-pending, T. (Only the last such T.) + * (If --no-triggers and nonempty argument list and package isn't in + * argument list then we don't do this.) + * + * Each time in process_queue() where we increment dependtry, we instead + * see if we have encountered such a t-pending T. If we do and are in + * a trigger processing try, we trigproc T instead of incrementing + * dependtry and this counts as having done something so we reset + * sincenothing. + * + * + * For --triggers-only and --configure, we go through each thing in the + * argument queue (the enqueue_package queue) and check what its state is + * and if appropriate we trigproc it. If we didn't have a queue (or had + * just --pending) we search all triggers-pending packages and add them + * to the deferred trigproc list. + * + * + * Before quitting from most operations, we trigproc each package in the + * deferred trigproc list. This may (if not --no-triggers) of course add + * new things to the deferred trigproc list. + * + * + * Note that ‘we trigproc T’ must involve trigger cycle detection and + * also automatic setting of t-awaiters to t-pending or installed. In + * particular, we do cycle detection even for trigger processing in the + * configure dependtry loop (and it is OK to do it for explicitly + * specified packages from the command line arguments; duplicates are + * removed by packages.c:process_queue). + */ + +/*========== Deferred trigger queue. ==========*/ + +static struct pkg_queue deferred = PKG_QUEUE_INIT; + +static void +trigproc_enqueue_deferred(struct pkginfo *pend) +{ + if (f_triggers < 0) + return; + ensure_package_clientdata(pend); + if (pend->clientdata->trigprocdeferred) + return; + pend->clientdata->trigprocdeferred = pkg_queue_push(&deferred, pend); + debug(dbg_triggers, "trigproc_enqueue_deferred pend=%s", + pkg_name(pend, pnaw_always)); +} + +/** + * Populate the deferred trigger queue. + * + * When dpkg is called with a specific set of packages to act on, we might + * have packages pending trigger processing. But because there are frontends + * that do not perform a final «dpkg --configure --pending» call (i.e. apt), + * the system is left in a state with packages not fully installed. + * + * We have to populate the deferred trigger queue from the entire package + * database, so that we might try to do opportunistic trigger processing + * when going through the deferred trigger queue, because a fixed apt will + * not request the necessary processing anyway. + * + * XXX: This can be removed once apt is fixed in the next stable release. + */ +void +trigproc_populate_deferred(void) +{ + struct pkg_hash_iter *iter; + struct pkginfo *pkg; + + iter = pkg_hash_iter_new(); + while ((pkg = pkg_hash_iter_next_pkg(iter))) { + if (!pkg->trigpend_head) + continue; + + if (pkg->status != PKG_STAT_TRIGGERSAWAITED && + pkg->status != PKG_STAT_TRIGGERSPENDING) + continue; + + if (pkg->want != PKG_WANT_INSTALL && + pkg->want != PKG_WANT_HOLD) + continue; + + trigproc_enqueue_deferred(pkg); + } + pkg_hash_iter_free(iter); +} + +void +trigproc_run_deferred(void) +{ + jmp_buf ejbuf; + + debug(dbg_triggers, "trigproc_run_deferred"); + while (!pkg_queue_is_empty(&deferred)) { + struct pkginfo *pkg; + + pkg = pkg_queue_pop(&deferred); + if (!pkg) + continue; + + if (setjmp(ejbuf)) { + pop_error_context(ehflag_bombout); + continue; + } + push_error_context_jump(&ejbuf, print_error_perpackage, + pkg_name(pkg, pnaw_nonambig)); + + ensure_package_clientdata(pkg); + pkg->clientdata->trigprocdeferred = NULL; + trigproc(pkg, TRIGPROC_TRY_DEFERRED); + + pop_error_context(ehflag_normaltidy); + } +} + +/* + * Called by modstatdb_note. + */ +void +trig_activate_packageprocessing(struct pkginfo *pkg) +{ + debug(dbg_triggersdetail, "trigproc_activate_packageprocessing pkg=%s", + pkg_name(pkg, pnaw_always)); + + trig_parse_ci(pkg_infodb_get_file(pkg, &pkg->installed, TRIGGERSCIFILE), + NULL, trig_cicb_statuschange_activate, + pkg, &pkg->installed); +} + +/*========== Actual trigger processing. ==========*/ + +struct trigcyclenode { + struct trigcyclenode *next; + struct trigcycleperpkg *pkgs; + struct pkginfo *then_processed; +}; + +struct trigcycleperpkg { + struct trigcycleperpkg *next; + struct pkginfo *pkg; + struct trigpend *then_trigs; +}; + +static bool tortoise_advance; +static struct trigcyclenode *tortoise, *hare; + +void +trigproc_reset_cycle(void) +{ + tortoise_advance = false; + tortoise = hare = NULL; +} + +static bool +tortoise_in_hare(struct pkginfo *processing_now, + struct trigcycleperpkg *tortoise_pkg) +{ + const char *processing_now_name, *tortoise_name; + struct trigpend *hare_trig, *tortoise_trig; + + processing_now_name = pkg_name(processing_now, pnaw_nonambig); + tortoise_name = pkg_name(tortoise_pkg->pkg, pnaw_nonambig); + + debug(dbg_triggersdetail, "%s pnow=%s tortoise=%s", __func__, + processing_now_name, tortoise_name); + for (tortoise_trig = tortoise_pkg->then_trigs; + tortoise_trig; + tortoise_trig = tortoise_trig->next) { + debug(dbg_triggersdetail, + "%s pnow=%s tortoise=%s tortoisetrig=%s", __func__, + processing_now_name, tortoise_name, tortoise_trig->name); + + /* hare is now so we can just look up in the actual data. */ + for (hare_trig = tortoise_pkg->pkg->trigpend_head; + hare_trig; + hare_trig = hare_trig->next) { + debug(dbg_triggersstupid, "%s pnow=%s tortoise=%s" + " tortoisetrig=%s haretrig=%s", __func__, + processing_now_name, tortoise_name, + tortoise_trig->name, hare_trig->name); + if (strcmp(hare_trig->name, tortoise_trig->name) == 0) + break; + } + + if (hare_trig == NULL) { + /* Not found in hare, yay! */ + debug(dbg_triggersdetail, "%s pnow=%s tortoise=%s OK", + __func__, processing_now_name, tortoise_name); + return false; + } + } + + return true; +} + +static struct trigcyclenode * +trigproc_new_cyclenode(struct pkginfo *processing_now) +{ + struct trigcyclenode *tcn; + struct trigcycleperpkg *tcpp; + struct pkginfo *pkg; + struct pkg_hash_iter *iter; + + tcn = nfmalloc(sizeof(*tcn)); + tcn->pkgs = NULL; + tcn->next = NULL; + tcn->then_processed = processing_now; + + iter = pkg_hash_iter_new(); + while ((pkg = pkg_hash_iter_next_pkg(iter))) { + if (!pkg->trigpend_head) + continue; + tcpp = nfmalloc(sizeof(*tcpp)); + tcpp->pkg = pkg; + tcpp->then_trigs = pkg->trigpend_head; + tcpp->next = tcn->pkgs; + tcn->pkgs = tcpp; + } + pkg_hash_iter_free(iter); + + return tcn; +} + +/* + * Returns package we are to give up on. + */ +static struct pkginfo * +check_trigger_cycle(struct pkginfo *processing_now) +{ + struct trigcyclenode *tcn; + struct trigcycleperpkg *tortoise_pkg; + struct trigpend *tortoise_trig; + struct pkginfo *giveup; + const char *sep; + + debug(dbg_triggers, "check_triggers_cycle pnow=%s", + pkg_name(processing_now, pnaw_always)); + + tcn = trigproc_new_cyclenode(processing_now); + + if (!hare) { + debug(dbg_triggersdetail, "check_triggers_cycle pnow=%s first", + pkg_name(processing_now, pnaw_always)); + hare = tortoise = tcn; + return NULL; + } + + hare->next = tcn; + hare = hare->next; + if (tortoise_advance) + tortoise = tortoise->next; + tortoise_advance = !tortoise_advance; + + /* Now we compare hare to tortoise. + * We want to find a trigger pending in tortoise which is not in hare + * if we find such a thing we have proved that hare isn't a superset + * of tortoise and so that we haven't found a loop (yet). */ + for (tortoise_pkg = tortoise->pkgs; + tortoise_pkg; + tortoise_pkg = tortoise_pkg->next) { + if (!tortoise_in_hare(processing_now, tortoise_pkg)) + return NULL; + } + /* Oh dear. hare is a superset of tortoise. We are making no + * progress. */ + notice(_("cycle found while processing triggers:\n" + " chain of packages whose triggers are or may be responsible:")); + sep = " "; + for (tcn = tortoise; tcn; tcn = tcn->next) { + fprintf(stderr, "%s%s", sep, + pkg_name(tcn->then_processed, pnaw_nonambig)); + sep = " -> "; + } + fprintf(stderr, _("\n" " packages' pending triggers which are" + " or may be unresolvable:\n")); + for (tortoise_pkg = tortoise->pkgs; + tortoise_pkg; + tortoise_pkg = tortoise_pkg->next) { + fprintf(stderr, " %s", + pkg_name(tortoise_pkg->pkg, pnaw_nonambig)); + sep = ": "; + for (tortoise_trig = tortoise_pkg->then_trigs; + tortoise_trig; + tortoise_trig = tortoise_trig->next) { + fprintf(stderr, "%s%s", sep, tortoise_trig->name); + } + fprintf(stderr, "\n"); + } + + /* We give up on the _earliest_ package involved. */ + giveup = tortoise->pkgs->pkg; + debug(dbg_triggers, "check_triggers_cycle pnow=%s giveup=%s", + pkg_name(processing_now, pnaw_always), + pkg_name(giveup, pnaw_always)); + if (giveup->status != PKG_STAT_TRIGGERSAWAITED && + giveup->status != PKG_STAT_TRIGGERSPENDING) + internerr("package %s in non-trigger state %s", + pkg_name(giveup, pnaw_always), + pkg_status_name(giveup)); + giveup->clientdata->istobe = PKG_ISTOBE_NORMAL; + pkg_set_status(giveup, PKG_STAT_HALFCONFIGURED); + modstatdb_note(giveup); + print_error_perpackage(_("triggers looping, abandoned"), + pkg_name(giveup, pnaw_nonambig)); + + return giveup; +} + +/* + * Does cycle checking. Doesn't mind if pkg has no triggers pending - in + * that case does nothing but fix up any stale awaiters. + */ +void +trigproc(struct pkginfo *pkg, enum trigproc_type type) +{ + static struct varbuf namesarg; + + struct varbuf depwhynot = VARBUF_INIT; + + debug(dbg_triggers, "trigproc %s", pkg_name(pkg, pnaw_always)); + + ensure_package_clientdata(pkg); + if (pkg->clientdata->trigprocdeferred) + pkg->clientdata->trigprocdeferred->pkg = NULL; + pkg->clientdata->trigprocdeferred = NULL; + + if (pkg->trigpend_head) { + struct pkginfo *gaveup; + struct trigpend *tp; + enum dep_check ok; + + if (pkg->status != PKG_STAT_TRIGGERSPENDING && + pkg->status != PKG_STAT_TRIGGERSAWAITED) + internerr("package %s in non-trigger state %s", + pkg_name(pkg, pnaw_always), + pkg_status_name(pkg)); + + if (dependtry < DEPEND_TRY_TRIGGERS && + type == TRIGPROC_TRY_QUEUED) { + /* We are not yet in a triggers run, so postpone this + * package completely. */ + enqueue_package(pkg); + return; + } + + if (dependtry >= DEPEND_TRY_CYCLES) { + if (findbreakcycle(pkg)) + sincenothing = 0; + } + + ok = dependencies_ok(pkg, NULL, &depwhynot); + if (ok == DEP_CHECK_DEFER) { + if (dependtry >= DEPEND_TRY_TRIGGERS_CYCLES) { + gaveup = check_trigger_cycle(pkg); + if (gaveup == pkg) + return; + } + + varbuf_destroy(&depwhynot); + enqueue_package(pkg); + return; + } else if (ok == DEP_CHECK_HALT) { + /* When doing opportunistic deferred trigger processing, + * nothing requires us to be able to make progress; + * skip the package and silently ignore the error due + * to unsatisfiable dependencies. And because we can + * end up here repeatedly, if this package is required + * to make progress for other packages, we need to + * reset the trigger cycle tracking to avoid detecting + * bogus cycles*/ + if (type == TRIGPROC_TRY_DEFERRED) { + trigproc_reset_cycle(); + + varbuf_destroy(&depwhynot); + return; + } + + sincenothing = 0; + varbuf_end_str(&depwhynot); + notice(_("dependency problems prevent processing " + "triggers for %s:\n%s"), + pkg_name(pkg, pnaw_nonambig), depwhynot.buf); + varbuf_destroy(&depwhynot); + ohshit(_("dependency problems - leaving triggers unprocessed")); + } else if (depwhynot.used) { + varbuf_end_str(&depwhynot); + notice(_("%s: dependency problems, but processing " + "triggers anyway as you requested:\n%s"), + pkg_name(pkg, pnaw_nonambig), depwhynot.buf); + varbuf_destroy(&depwhynot); + } + + gaveup = check_trigger_cycle(pkg); + if (gaveup == pkg) + return; + + printf(_("Processing triggers for %s (%s) ...\n"), + pkg_name(pkg, pnaw_nonambig), + versiondescribe(&pkg->installed.version, vdew_nonambig)); + log_action("trigproc", pkg, &pkg->installed); + + varbuf_reset(&namesarg); + for (tp = pkg->trigpend_head; tp; tp = tp->next) { + varbuf_add_char(&namesarg, ' '); + varbuf_add_str(&namesarg, tp->name); + } + varbuf_end_str(&namesarg); + + /* Setting the status to half-configured + * causes modstatdb_note to clear pending triggers. */ + pkg_set_status(pkg, PKG_STAT_HALFCONFIGURED); + modstatdb_note(pkg); + + if (!f_noact) { + sincenothing = 0; + maintscript_postinst(pkg, "triggered", + namesarg.buf + 1, NULL); + } + + post_postinst_tasks(pkg, PKG_STAT_INSTALLED); + } else { + /* In other branch is done by modstatdb_note(), from inside + * post_postinst_tasks(). */ + trig_clear_awaiters(pkg); + } +} + +/*========== Transitional global activation. ==========*/ + +static void +transitional_interest_callback_ro(const char *trig, struct pkginfo *pkg, + struct pkgbin *pkgbin, enum trig_options opts) +{ + struct pkginfo *pend = pkg; + struct pkgbin *pendbin = pkgbin; + + debug(dbg_triggersdetail, + "trig_transitional_interest_callback trig=%s pend=%s", + trig, pkgbin_name(pend, pendbin, pnaw_always)); + if (pend->status >= PKG_STAT_TRIGGERSAWAITED) + trig_note_pend(pend, nfstrsave(trig)); +} + +static void +transitional_interest_callback(const char *trig, struct pkginfo *pkg, + struct pkgbin *pkgbin, enum trig_options opts) +{ + struct pkginfo *pend = pkg; + struct pkgbin *pendbin = pkgbin; + + trig_cicb_interest_add(trig, pend, pendbin, opts); + transitional_interest_callback_ro(trig, pend, pendbin, opts); +} + +/* + * cstatus might be msdbrw_readonly if we're in --no-act mode, in which + * case we don't write out all of the interest files etc. but we do + * invent all of the activations for our own benefit. + */ +static void +trig_transitional_activate(enum modstatdb_rw cstatus) +{ + struct pkg_hash_iter *iter; + struct pkginfo *pkg; + + iter = pkg_hash_iter_new(); + while ((pkg = pkg_hash_iter_next_pkg(iter))) { + if (pkg->status <= PKG_STAT_HALFINSTALLED) + continue; + debug(dbg_triggersdetail, "trig_transitional_activate %s %s", + pkg_name(pkg, pnaw_always), + pkg_status_name(pkg)); + pkg->trigpend_head = NULL; + trig_parse_ci(pkg_infodb_get_file(pkg, &pkg->installed, + TRIGGERSCIFILE), + cstatus >= msdbrw_write ? + transitional_interest_callback : + transitional_interest_callback_ro, NULL, + pkg, &pkg->installed); + /* Ensure we're not creating incoherent data that can't + * be written down. This should never happen in theory but + * can happen if you restore an old status file that is + * not in sync with the infodb files. */ + if (pkg->status < PKG_STAT_TRIGGERSAWAITED) + continue; + + if (pkg->trigaw.head) + pkg_set_status(pkg, PKG_STAT_TRIGGERSAWAITED); + else if (pkg->trigpend_head) + pkg_set_status(pkg, PKG_STAT_TRIGGERSPENDING); + else + pkg_set_status(pkg, PKG_STAT_INSTALLED); + } + pkg_hash_iter_free(iter); + + if (cstatus >= msdbrw_write) { + modstatdb_checkpoint(); + trig_file_interests_save(); + } +} + +/*========== Hook setup. ==========*/ + +TRIGHOOKS_DEFINE_NAMENODE_ACCESSORS + +static const struct trig_hooks trig_our_hooks = { + .enqueue_deferred = trigproc_enqueue_deferred, + .transitional_activate = trig_transitional_activate, + .namenode_find = th_nn_find, + .namenode_interested = th_nn_interested, + .namenode_name = th_nn_name, +}; + +void +trigproc_install_hooks(void) +{ + trig_override_hooks(&trig_our_hooks); +} |