+/*
+ * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file filter_common.c Common helper functions for filter input/output. */
+
+#include <sys/types.h>
+#include <dirent.h>
+
+#include "para.h"
+#include "list.h"
+#include "sched.h"
+#include "fd.h"
+#include "filter.h"
+#include "error.h"
+#include "string.h"
+
+/** The array of supported filters. */
+struct filter filters[NUM_SUPPORTED_FILTERS] = {FILTER_ARRAY};
+
+/**
+ * Call the init function of each supported filter.
+ *
+ * \param all_filters the array of all supported filters.
+ *
+ * \sa filter::init
+ */
+void filter_init(struct filter *all_filters)
+{
+ int i;
+
+ FOR_EACH_SUPPORTED_FILTER(i)
+ all_filters[i].init(all_filters + i);
+}
+
+/**
+ * Close and destroy a filter callback.
+ *
+ * \param fcb The filter callback to close.
+ *
+ * This removes \a fcb from the list of filter callbacks and calls
+ * the close callback associated with \a fcb.
+ */
+static void close_filter_callback(struct filter_callback *fcb)
+{
+ PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb, fcb->data);
+ list_del(&fcb->node);
+ fcb->close(fcb);
+}
+
+/**
+ * Close all callbacks of a filter node.
+ *
+ * \param fn The filter node which contains the filter callbacks to be closed.
+ *
+ * Call close_filter_callback() for each entry in the filter callback list
+ * of \a fn.
+ */
+static void close_callbacks(struct filter_node *fn)
+{
+ struct filter_callback *fcb, *tmp;
+
+ list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
+ PARA_INFO_LOG("closing %s filter callback\n",
+ filters[fn->filter_num].name);
+ close_filter_callback(fcb);
+ }
+}
+
+static void call_callbacks(struct filter_node *fn, char *inbuf, size_t inlen,
+ char *outbuf, size_t outlen)
+{
+ struct filter_callback *fcb, *tmp;
+ list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
+ int ret;
+ if (inlen && fcb->input_cb) {
+ ret = fcb->input_cb(inbuf, inlen, fcb);
+ if (ret < 0) {
+ close_filter_callback(fcb);
+ continue;
+ }
+ }
+ if (!outlen || !fcb->output_cb)
+ continue;
+ ret = fcb->output_cb(outbuf, outlen, fcb);
+ if (ret < 0)
+ close_filter_callback(fcb);
+ }
+}
+
+/**
+ * Call the convert function of each filter.
+ *
+ * \param s Unused.
+ * \param t The task identifying the filter chain.
+ *
+ * This is the core function of the filter subsystem. It loops over the list of
+ * filter nodes determined by \a t and calls the filter's convert function if
+ * there is input available for the filter node in question. If the convert
+ * function consumed some or all of its input data, all registered input
+ * callbacks are called. Similarly, if a convert function produced output, all
+ * registerd output callbacks get called.
+ *
+ * On errors a (negative) error code is stored in t->error.
+ *
+ * \sa filter_node, filter#convert, filter_callback.
+ */
+void filter_pre_select(__a_unused struct sched *s, struct task *t)
+{
+ struct filter_chain *fc = container_of(t, struct filter_chain, task);
+ struct filter_node *fn;
+ char *ib;
+ size_t *loaded;
+ int i, conv, conv_total = 0;
+
+ if (fc->output_error && *fc->output_error < 0) {
+ t->error = *fc->output_error;
+ return;
+ }
+again:
+ ib = fc->inbuf;
+ loaded = fc->in_loaded;
+ conv = 0;
+ FOR_EACH_FILTER_NODE(fn, fc, i) {
+ struct filter *f = filters + fn->filter_num;
+ if (fn->loaded < fn->bufsize) {
+ size_t size, old_fn_loaded = fn->loaded;
+// PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
+// fc, *loaded, fn->filter->name);
+ t->error = f->convert(ib, *loaded, fn);
+ if (t->error < 0)
+ return;
+ size = t->error;
+ call_callbacks(fn, ib, size, fn->buf + old_fn_loaded,
+ fn->loaded - old_fn_loaded);
+ *loaded -= size;
+ conv += size;
+ if (*loaded && size) {
+// PARA_DEBUG_LOG("moving %zd bytes in input "
+// "buffer for %s filter\n",
+// *loaded, fn->filter->name);
+ memmove(ib, ib + size, *loaded);
+ }
+ }
+ ib = fn->buf;
+ loaded = &fn->loaded;
+ }
+ conv_total += conv;
+// PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
+// "conv: %d, conv_total: %d\n", *fc->input_eof,
+// fc->output_eof? *fc->output_eof : -42,
+// fc->eof, *fc->out_loaded, conv, conv_total);
+ if (conv)
+ goto again;
+ if (!*fc->input_error)
+ return;
+ if (*fc->out_loaded)
+ return;
+ if (*fc->in_loaded && conv_total)
+ return;
+ t->error = -E_FC_EOF;
+}
+
+/**
+ * Close all filter nodes and their callbacks.
+ *
+ * \param fc The filter chain to close.
+ *
+ * For each filter node determined by \a fc, call the close function of each
+ * registered filter callback as well as the close function of the
+ * corresponding filter. Free all resources and destroy all callback lists and
+ * the filter node list.
+ *
+ * \sa filter::close, filter_callback::close
+ */
+void close_filters(struct filter_chain *fc)
+{
+ struct filter_node *fn;
+ int i;
+
+ if (!fc)
+ return;
+ PARA_NOTICE_LOG("closing filter chain %p\n", fc);
+ FOR_EACH_FILTER_NODE(fn, fc, i) {
+ struct filter *f = filters + fn->filter_num;
+ close_callbacks(fn);
+ PARA_INFO_LOG("closing %s filter\n", f->name);
+ f->close(fn);
+ }
+ free(fc->filter_nodes);
+}
+
+/*
+ * If the filter has a command line parser and options is not NULL, run it.
+ * Returns filter_num on success, negative on errors
+ */
+static int parse_filter_args(int filter_num, char *options, void **conf)
+{
+ struct filter *f = &filters[filter_num];
+ int ret, i, argc = 2;
+ char **argv;
+
+// PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
+// options? options : "(none)", f->parse_config);
+ if (!f->parse_config)
+ return strlen(options)? -E_BAD_FILTER_OPTIONS : filter_num;
+// PARA_DEBUG_LOG("options: %s\n", options);
+ argc = split_args(options, &argv, " \t");
+// PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
+ for (i = argc - 1; i >= 0; i--)
+ argv[i + 1] = argv[i];
+ argv[0] = para_strdup(f->name);
+ argc += 1;
+ ret = f->parse_config(argc, argv, conf);
+ free(argv[0]);
+ free(argv);
+ return ret < 0? ret : filter_num;
+}
+
+/**
+ * Check the filter command line options.
+ *
+ * \param fa The command line options.
+ * \param conf Points to the filter configuration upon successful return.
+ *
+ * Check if \a fa starts with a the name of a supported filter, followed by
+ * a colon. If yes, call the command line parser of that filter.
+ *
+ * \return On success, the number of the filter is returned and \a conf
+ * is initialized to point to the filter configuration determined by \a fa.
+ * On errors, a negative value is returned.
+ *
+ * Note: If \a fa specifies a filter that has no command line parser success is
+ * returned, and \a conf is initialized to \p NULL.
+ *
+ * \sa filter::parse_config
+ */
+int check_filter_arg(char *fa, void **conf)
+{
+ int j;
+
+ *conf = NULL;
+// PARA_DEBUG_LOG("arg: %s\n", fa);
+ FOR_EACH_SUPPORTED_FILTER(j) {
+ const char *name = filters[j].name;
+ size_t len = strlen(name);
+ char c;
+ if (strlen(fa) < len)
+ continue;
+ if (strncmp(name, fa, len))
+ continue;
+ c = fa[len];
+ if (c && c != ' ')
+ continue;
+ if (c && !filters[j].parse_config)
+ return -E_BAD_FILTER_OPTIONS;
+ return parse_filter_args(j, c? fa + len + 1 :
+ fa + strlen(fa), conf);
+ }
+ return -E_UNSUPPORTED_FILTER;
+}
+