Fixes mostly in coding style, added some comments.

diff --git a/net/sched/cls_canprio.c b/net/sched/cls_canprio.c
index 817948505bdc2c5596a66ddceadd00e6a295aa0c..a3380c43ef16a0bb5f5b89bab301fbe857be7b6e 100644 (file)
--- a/net/sched/cls_canprio.c
+++ b/net/sched/cls_canprio.c
@@ -1,17 +1,23 @@
 /* 
  * cls_canprio.c  -- Canprio classifier.
- * Makes decisions accoring to Can IDs.
+ * Makes decisions accoring to controller area network (CAN) identifiers.
  *
  *             This program is free software; you can distribute it and/or
  *             modify it under the terms of the GNU General Public License
  *             as published by the Free Software Foundation; version 2 of
  *             the License.
  * 
+ * Idea:       Oliver Hartkopp <oliver.hartkopp@volkswagen.de> 
  * Copyright:  (c) 2011 Czech Technical University in Prague
+ *             (c) 2011 Volkswagen Group Research
  * Authors:    Michal Sojka <sojkam1@fel.cvut.cz>
  *             Pavel Pisa <pisa@cmp.felk.cvut.cz>
  *             Rostislav Lisovy <lisovy@kormus.cz>
+ * Founded by: Volkswagen Group Research
  *
+ * Some function descriptions are heavily inspired by article "Linux Network
+ * Traffic Control -- Implementation Overview" by Werner Almesberger
+ * 
  *
  * Implementation notes;
  *   parameter of functions named "base" is pointer to some parent element
@@ -57,7 +63,7 @@ enum {
 static const struct nla_policy canprio_policy[TCA_CANPRIO_MAX + 1] = {
        [TCA_CANPRIO_CLASSID]    = { .type = NLA_U32 },
        //FIXME Be aware of possible problems with 64bit kernel and 32bit userspace etc.
-       [TCA_CANPRIO_RULES]      = { /*.len = (sizeof(struct canprio_rule)*32)*/ }, /* FIXME */
+       [TCA_CANPRIO_RULES]      = { .len = (sizeof(struct canprio_rule)) }, //FIXME
        [TCA_CANPRIO_INV_EN]     = { .type = NLA_U32 },
 };
 
@@ -88,7 +94,7 @@ struct canprio_filter {
  * ----------------------------------------------------------------------------
  */
 
-static void sff_match_add(struct canprio_filter *f, u32 canid, u32 mask)
+static void canprio_sff_match_add(struct canprio_filter *f, u32 canid, u32 mask)
 {
        int i;
 
@@ -107,7 +113,7 @@ static void sff_match_add(struct canprio_filter *f, u32 canid, u32 mask)
        }
 }
 
-static int eff_match_add(struct canprio_filter *f, u32 canid, u32 mask)
+static int canprio_eff_match_add(struct canprio_filter *f, u32 canid, u32 mask)
 {
        struct canprio_eff_item *eff;
        int err = 0;
@@ -256,8 +262,7 @@ static void canprio_put(struct tcf_proto *tp, unsigned long f)
 }
 
 
-/* FIXME all functions with prefixes? */
-static unsigned int gen_handle(struct tcf_proto *tp)
+static unsigned int canprio_gen_handle(struct tcf_proto *tp)
 {
        struct canprio_head *head = (struct canprio_head *)tp->root;
        int i = 0xFFFF;
@@ -307,28 +312,27 @@ static int canprio_change(struct tcf_proto *tp, unsigned long base, u32 handle,
        if (tca[TCA_OPTIONS] == NULL)
                return -EINVAL;
 
-       //Parses a stream of attributes and stores a pointer to each attribute in
-       //the tb array accessible via the attribute type. Policy may be set to NULL 
-       //if no validation is required.
+       /*Parses a stream of attributes and stores a pointer to each attribute in
+         the tb array accessible via the attribute type. Policy may be set to NULL 
+         if no validation is required.*/
        err = nla_parse_nested(tb, TCA_CANPRIO_MAX, tca[TCA_OPTIONS], canprio_policy);
        if (err < 0)                
                return err;
 
-       //Change existing filter (?)
+       //Change existing filter
        if (f != NULL) {
                if (handle && f->handle != handle)
                        return -EINVAL;
                return canprio_set_parms(tp, f, base, tb, tca[TCA_RATE]);
        }
 
-       //Create new filter (?)
+       //Create new filter
        err = -ENOBUFS;
        f = kzalloc(sizeof(*f), GFP_KERNEL);
        if (f == NULL)
                goto errout;
 
 
-       //FIXME why?
        err = -EINVAL;
        if (handle)
                f->handle = handle;
@@ -346,7 +350,7 @@ static int canprio_change(struct tcf_proto *tp, unsigned long base, u32 handle,
                        goto errout;
                }
        */
-               handle = gen_handle(tp);        
+               handle = canprio_gen_handle(tp);        
                //printk("__new handle %d\n", handle);
                f->handle = handle;
                //FIXME where is hgenerator initialized
@@ -372,11 +376,11 @@ static int canprio_change(struct tcf_proto *tp, unsigned long base, u32 handle,
                 * can_rcv_filter() to filter for various combination
                 * of flags (EFF, RTR) */
                if (canprio_rules[i].canid & CAN_EFF_FLAG) {
-                       err = eff_match_add(f, canprio_rules[i].canid, canprio_rules[i].canid_mask);
+                       err = canprio_eff_match_add(f, canprio_rules[i].canid, canprio_rules[i].canid_mask);
                        if (err < 0)
                                goto errout;
                } else {
-                       sff_match_add(f, canprio_rules[i].canid, canprio_rules[i].canid_mask);
+                       canprio_sff_match_add(f, canprio_rules[i].canid, canprio_rules[i].canid_mask);
                }
 
                printk(" can ID to match = 0x%x with mask 0x%x\n", 
@@ -396,7 +400,7 @@ static int canprio_change(struct tcf_proto *tp, unsigned long base, u32 handle,
        return 0;
 
 errout:
-       if (*arg == 0UL && f) //FIXME why 0UL?
+       if (*arg == 0UL && f)
                kfree(f);
 
        return err;
@@ -456,7 +460,10 @@ static int canprio_delete(struct tcf_proto *tp, unsigned long arg)
        return -ENOENT;
 }
 
-//FIXME copied from cls_basic, not sure if ok;
+
+/*
+ * Initialize filter
+ */
 static int canprio_init(struct tcf_proto *tp)
 {
        struct canprio_head *head;
@@ -466,6 +473,7 @@ static int canprio_init(struct tcf_proto *tp)
        head = kzalloc(sizeof(*head), GFP_KERNEL);
        if (head == NULL)
                return -ENOBUFS;
+
        INIT_LIST_HEAD(&head->flist);
        tp->root = head;
        tp->protocol = htons(ETH_P_CAN); /* Work only on AF_CAN packets - not tested! */
@@ -473,7 +481,10 @@ static int canprio_init(struct tcf_proto *tp)
        return 0;
 }
 
-
+/*
+ * Iterates over all elements of a filter and invokes a callback function
+ * for each of them. This is used to obtain diagnostic data
+ */
 static void canprio_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 {
        struct canprio_head *head = (struct canprio_head *) tp->root;
@@ -495,6 +506,9 @@ skip:
        }
 }
 
+/* 
+ * Returns diagnostic data for a filter or one of its elements. 
+ */
 static int canprio_dump(struct tcf_proto *tp, unsigned long fh,
                     struct sk_buff *skb, struct tcmsg *t)
 {
@@ -562,5 +576,5 @@ module_init(init_canprio);
 module_exit(exit_canprio);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR(""); // FIXME
-MODULE_DESCRIPTION("");
+MODULE_DESCRIPTION("Controller Area Network can_id classifier");