Add plugin calling support

This patch adds a simple plugin system that makes simple problems easy to
solve, and difficult problems, such as SELinux, possible.

When the transaction gets to the point where a collection action should occur,
it expands a macro of the form %__collection_<collection name> to get the path
to a plugin and any additional options. The plugin is dlopen'ed, and the
appropriate function is called in the plugin, with the additional arguments
passed in.

This also adds a --nocollections option to disable performing Collection
actions.

6 files changed, 165 insertions, 1 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index c308bc658..1357c7c5b 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -33,7 +33,8 @@ librpm_la_SOURCES = \
 	rpmvercmp.c signature.c signature.h transaction.c \
 	verify.c rpmlock.c rpmlock.h misc.h \
 	rpmscript.h rpmscript.c legacy.c merge.c \
-	rpmliblua.c rpmliblua.h rpmchroot.c rpmchroot.h
+	rpmliblua.c rpmliblua.h rpmchroot.c rpmchroot.h \
+	collections.h
 
 librpm_la_LDFLAGS = -version-info 1:0:0
 
diff --git a/lib/collections.h b/lib/collections.h
new file mode 100644
index 000000000..78fbaecc4
--- /dev/null
+++ b/lib/collections.h
@@ -0,0 +1,26 @@
+#ifndef _COLLECTIONS_H
+#define _COLLECTIONS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef rpmRC(*collHookFunc) (rpmts, const char *, const char *);
+
+#define COLLHOOK_POST_ADD_FUNC		post_add
+#define COLLHOOK_POST_ANY_FUNC		post_any
+#define COLLHOOK_PRE_REMOVE_FUNC	pre_remove
+
+#define COLLECTION_HOOKS	collection_hooks
+typedef enum rpmCollHook_e {
+    COLLHOOK_NONE		= 0,
+    COLLHOOK_POST_ADD		= 1 << 0,
+    COLLHOOK_POST_ANY		= 1 << 1,
+    COLLHOOK_PRE_REMOVE		= 1 << 2
+} rpmCollHook;
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _COLLECTIONS_H */
diff --git a/lib/poptI.c b/lib/poptI.c
index 5021f17f9..c30c3b5af 100644
--- a/lib/poptI.c
+++ b/lib/poptI.c
@@ -254,6 +254,10 @@ struct poptOption rpmInstallPoptTable[] = {
 	&rpmIArgs.transFlags, RPMTRANS_FLAG_NOTRIGGERPOSTUN,
 	N_("do not execute any %%triggerpostun scriptlet(s)"), NULL},
 
+ { "nocollections", '\0', POPT_BIT_SET,
+	&rpmIArgs.transFlags, RPMTRANS_FLAG_NOCOLLECTIONS,
+	N_("do not perform any collection actions"), NULL},
+
  { "oldpackage", '\0', POPT_BIT_SET,
 	&rpmIArgs.probFilter, RPMPROB_FILTER_OLDPACKAGE,
 	N_("upgrade to an old version of the package (--force on upgrades does this automatically)"),
diff --git a/lib/rpmte.c b/lib/rpmte.c
index 7765f70cb..e622558ed 100644
--- a/lib/rpmte.c
+++ b/lib/rpmte.c
@@ -6,11 +6,13 @@
 
 #include <rpm/rpmtypes.h>
 #include <rpm/rpmlib.h>		/* RPM_MACHTABLE_* */
+#include <rpm/rpmmacro.h>
 #include <rpm/rpmds.h>
 #include <rpm/rpmfi.h>
 #include <rpm/rpmts.h>
 #include <rpm/rpmdb.h>
 
+#include "lib/collections.h"
 #include "lib/rpmte_internal.h"
 
 #include "debug.h"
@@ -748,6 +750,129 @@ rpmfs rpmteGetFileStates(rpmte te) {
     return te->fs;
 }
 
+static int rpmteRunCollection(rpmte te, const char *collname,
+			      rpmCollHook hook)
+{
+#define STR1(x) #x
+#define STR(x) STR1(x)
+
+    void *handle = NULL;
+    collHookFunc hookFunc;
+    const char *hookFuncSym;
+    rpmCollHook *pluginHooks;
+    char *plugin;
+    char *options;
+    char *error;
+
+    int rc = RPMRC_FAIL;
+    if (rpmtsFlags(te->ts) & RPMTRANS_FLAG_NOCOLLECTIONS) {
+	return RPMRC_OK;
+    }
+
+    plugin = rpmExpand("%{?__collection_", collname, "}", NULL);
+    if (!plugin || rstreq(plugin, "")) {
+	fprintf(stderr, "Failed to expand %%__collection_%s macro\n",
+		collname);
+	goto exit;
+    }
+
+    /* split the options from the plugin string */
+#define SKIPSPACE(s)    { while (*(s) &&  risspace(*(s))) (s)++; }
+#define SKIPNONSPACE(s) { while (*(s) && !risspace(*(s))) (s)++; }
+    options = plugin;
+    SKIPNONSPACE(options);
+    if (risspace(*options)) {
+	*options = '\0';
+	options++;
+	SKIPSPACE(options);
+    }
+    if (*options == '\0') {
+	options = NULL;
+    }
+
+    handle = dlopen(plugin, RTLD_LAZY);
+    if (!handle) {
+	fprintf(stderr, "Failed to open %s: %s\n", plugin, dlerror());
+	goto exit;
+    }
+
+    dlerror();
+
+    pluginHooks = (rpmCollHook *) dlsym(handle, STR(COLLECTION_HOOKS));
+    if ((error = dlerror()) != NULL) {
+	fprintf(stderr, "Failed to resolve symbol: %s\n",
+		STR(COLLECTION_HOOKS));
+	goto exit;
+    }
+
+    if (!(*pluginHooks & hook)) {
+	/* plugin doesn't support this hook, exit */
+	rc = RPMRC_OK;
+	goto exit;
+    }
+
+    switch (hook) {
+    case COLLHOOK_POST_ADD:
+	hookFuncSym = STR(COLLHOOK_POST_ADD_FUNC);
+	break;
+    case COLLHOOK_POST_ANY:
+	hookFuncSym = STR(COLLHOOK_POST_ANY_FUNC);
+	break;
+    case COLLHOOK_PRE_REMOVE:
+	hookFuncSym = STR(COLLHOOK_PRE_REMOVE_FUNC);
+	break;
+    default:
+	goto exit;
+    }
+
+    *(void **) (&hookFunc) = dlsym(handle, hookFuncSym);
+    if ((error = dlerror()) != NULL) {
+	fprintf(stderr, "Failed to resolve symbol %s: %s\n",
+		hookFuncSym, error);
+	goto exit;
+    }
+
+    if (rpmtsFlags(te->ts) & (RPMTRANS_FLAG_TEST | RPMTRANS_FLAG_JUSTDB)) {
+	/* don't perform the action if --test or --justdb are set */
+	rc = RPMRC_OK;
+    } else {
+	rc = (*hookFunc) (te->ts, collname, options);
+    }
+
+  exit:
+    if (handle)
+	dlclose(handle);
+    _free(plugin);
+
+    return rc;
+}
+
+static rpmRC rpmteRunAllCollections(rpmte te, rpmCollHook hook)
+{
+    ARGV_const_t colls;
+    rpmRC rc = RPMRC_OK;
+
+    switch (hook) {
+    case COLLHOOK_POST_ADD:
+	colls = te->lastInCollectionsAdd;
+	break;
+    case COLLHOOK_POST_ANY:
+	colls = te->lastInCollectionsAny;
+	break;
+    case COLLHOOK_PRE_REMOVE:
+	colls = te->firstInCollectionsRemove;
+	break;
+    default:
+	colls = NULL;
+    }
+
+    for (; colls && *colls; colls++) {
+	rpmteRunCollection(te, *colls, hook);
+    }
+
+    return rc;
+}
+
 int rpmteProcess(rpmte te, pkgGoal goal)
 {
     /* Only install/erase resets pkg file info */
@@ -762,11 +887,16 @@ int rpmteProcess(rpmte te, pkgGoal goal)
 	}
     }
 
+    rpmteRunAllCollections(te, COLLHOOK_PRE_REMOVE);
+
     if (rpmteOpen(te, reset_fi)) {
 	failed = rpmpsmRun(te->ts, te, goal);
 	rpmteClose(te, reset_fi);
     }
     
+    rpmteRunAllCollections(te, COLLHOOK_POST_ADD);
+    rpmteRunAllCollections(te, COLLHOOK_POST_ANY);
+
     /* XXX should %pretrans failure fail the package install? */
     if (failed && !scriptstage) {
 	failed = rpmteMarkFailed(te);
diff --git a/lib/rpmts.h b/lib/rpmts.h
index a30ca30f2..9b7c30641 100644
--- a/lib/rpmts.h
+++ b/lib/rpmts.h
@@ -55,6 +55,7 @@ typedef enum rpmtransFlags_e {
     RPMTRANS_FLAG_NOTRIGGERPOSTUN = (1 << 23),	/*!< from --notriggerpostun */
     RPMTRANS_FLAG_NOPAYLOAD	= (1 << 24),
     RPMTRANS_FLAG_APPLYONLY	= (1 << 25),
+    RPMTRANS_FLAG_NOCOLLECTIONS	= (1 << 26),	/*!< from --nocollections */
 
     RPMTRANS_FLAG_NOMD5		= (1 << 27),	/*!< from --nomd5 */
     RPMTRANS_FLAG_NOFILEDIGEST	= (1 << 27),	/*!< from --nofiledigest (alias to --nomd5) */
diff --git a/system.h b/system.h
index ac18e16fa..e34f6d6d1 100644
--- a/system.h
+++ b/system.h
@@ -144,4 +144,6 @@ extern const char *__progname;
 #include "misc/fnmatch.h"
 #endif
 
+#include <dlfcn.h>
+
 #endif	/* H_SYSTEM */