[DCCP]: Debugging Feature Negotiation
Since all feature-negotiation processing now takes place in feat.c, functions for producing
verbose debugging output can be concentrated there. A number of functions to print out values,
entry records, and options are provided.
A new macro was defined to not always have the function name in the output line. I have refrained
from naming it dccp_pr_debug_dog ...
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/dccp.h | 2
net/dccp/feat.c | 151 +++++++++++++++++++++++++++++++++++++----------------
net/dccp/feat.h | 13 ----
net/dccp/options.c | 4 -
4 files changed, 109 insertions(+), 61 deletions(-)
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -42,9 +42,11 @@
extern int dccp_debug;
#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
+#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a)
#else
#define dccp_pr_debug(format, a...)
#define dccp_pr_debug_cat(format, a...)
+#define dccp_debug(format, a...)
#endif
extern struct inet_hashinfo dccp_hashinfo;
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -104,6 +104,100 @@ static int dccp_feat_default_value(u8 fe
return idx < 0 ? : dccp_feat_table[idx].default_value;
}
+/*
+ * Debugging and verbose-printing section
+ */
+static const char *dccp_feat_oname(const u8 opt)
+{
+ switch(opt) {
+ case DCCPO_CHANGE_L: return("Change_L");
+ case DCCPO_CONFIRM_L: return("Confirm_L");
+ case DCCPO_CHANGE_R: return("Change_R");
+ case DCCPO_CONFIRM_R: return("Confirm_R");
+ }
+ return NULL;
+}
+
+static const char *dccp_feat_fname(const u8 feat)
+{
+ static const char *feature_names[] = {
+ [DCCPF_RESERVED] = "Reserved",
+ [DCCPF_CCID] = "CCID",
+ [DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos",
+ [DCCPF_SEQUENCE_WINDOW] = "Sequence Window",
+ [DCCPF_ECN_INCAPABLE] = "ECN Incapable",
+ [DCCPF_ACK_RATIO] = "Ack Ratio",
+ [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector",
+ [DCCPF_SEND_NDP_COUNT] = "Send NDP Count",
+ [DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage",
+ [DCCPF_DATA_CHECKSUM] = "Send Data Checksum",
+ };
+ if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
+ return feature_names[DCCPF_RESERVED];
+
+ if (feat == DCCPF_SEND_LEV_RATE)
+ return "Send Loss Event Rate";
+ if (feat >= DCCPF_MIN_CCID_SPECIFIC)
+ return "CCID-specific";
+
+ return feature_names[feat];
+}
+
+static const char *dccp_feat_sname[] = { "DEFAULT", "INITIALISING", "CHANGING",
+ "UNSTABLE", "STABLE" };
+
+#ifdef CONFIG_IP_DCCP_DEBUG
+static void dccp_feat_printval(u8 feat_num, dccp_feat_val const *val)
+{
+ u8 i, type = dccp_feat_type(feat_num);
+
+ if (val == NULL || (type == FEAT_SP && val->sp.vec == NULL))
+ dccp_pr_debug_cat("(NULL)");
+ else if (type == FEAT_SP)
+ for (i = 0; i < val->sp.len; i++)
+ dccp_pr_debug_cat("%s%u", i ? " " : "", val->sp.vec[i]);
+ else if (type == FEAT_NN)
+ dccp_pr_debug_cat("%llu", (unsigned long long)val->nn);
+ else
+ dccp_pr_debug_cat("unknown type %u", type);
+}
+
+static void dccp_feat_printvals(u8 feat_num, u8 *list, u8 len)
+{
+ u8 type = dccp_feat_type(feat_num);
+ dccp_feat_val fval = { .sp.vec = list, .sp.len = len };
+
+ if (type == FEAT_NN)
+ fval.nn = dccp_decode_value_var(list, len);
+ dccp_feat_printval(feat_num, &fval);
+}
+
+static void dccp_feat_print_entry(struct dccp_feat_entry const *entry)
+{
+ dccp_debug(" * %s %s = ", entry->is_local ? "local" : "remote",
+ dccp_feat_fname(entry->feat_num));
+ dccp_feat_printval(entry->feat_num, &entry->val);
+ dccp_pr_debug_cat(", state=%s %s\n", dccp_feat_sname[entry->state],
+ entry->needs_confirm ? "(Confirm pending)" : "");
+}
+
+#define dccp_feat_print_opt(opt, feat, val, len, mandatory) \
+ dccp_pr_debug("%s(%s, ", dccp_feat_oname(opt), dccp_feat_fname(feat));\
+ dccp_feat_printvals(feat, val, len); \
+ dccp_pr_debug_cat(") %s\n", mandatory ? "!" : "");
+
+#define dccp_feat_print_fnlist(fn_list) { \
+ const struct dccp_feat_entry *entry; \
+ \
+ dccp_pr_debug("List Dump:\n"); \
+ list_for_each_entry(entry, fn_list, node) \
+ dccp_feat_print_entry(entry); \
+}
+#else /* ! CONFIG_IP_DCCP_DEBUG */
+#define dccp_feat_print_opt(opt, feat, fval, mandatory)
+#define dccp_feat_print_fnlist(fn_list)
+#endif
+
static int __dccp_feat_activate(struct sock *sk, const int idx,
const bool is_local, dccp_feat_val const *fval)
{
@@ -136,6 +230,10 @@ static int __dccp_feat_activate(struct s
/* Location is RX if this is a local-RX or remote-TX feature */
rx = (is_local == (dccp_feat_table[idx].rxtx == FEAT_AT_RX));
+ dccp_debug(" -> activating %s %s, %sval=%llu\n", rx ? "RX" : "TX",
+ dccp_feat_fname(dccp_feat_table[idx].feat_num),
+ fval ? "" : "default ", (unsigned long long)val);
+
return dccp_feat_table[idx].activation_hdlr(sk, val, rx);
}
@@ -434,6 +532,7 @@ int dccp_feat_insert_opts(struct dccp_so
return -1;
}
}
+ dccp_feat_print_opt(opt, pos->feat_num, ptr, len, 0);
if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt))
return -1;
@@ -689,6 +788,7 @@ int dccp_feat_finalise_settings(struct d
while (i--)
if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i))
return -1;
+ dccp_feat_print_fnlist(fn);
return 0;
}
@@ -802,6 +902,8 @@ static u8 dccp_feat_change_recv(struct l
if (len == 0 || type == FEAT_UNKNOWN) /* 6.1 and 6.6.8 */
goto unknown_feature_or_value;
+ dccp_feat_print_opt(opt, feat, val, len, is_mandatory);
+
/*
* Negotiation of NN features: Change R is invalid, so there is no
* simultaneous negotiation; hence we do not consult the list.
@@ -909,6 +1011,8 @@ static u8 dccp_feat_confirm_recv(struct
const bool local = (opt == DCCPO_CONFIRM_R);
struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local);
+ dccp_feat_print_opt(opt, feat, val, len, is_mandatory);
+
if (entry == NULL) { /* nothing queued: ignore or handle error */
if (is_mandatory && type == FEAT_UNKNOWN)
return DCCP_RESET_CODE_MANDATORY_ERROR;
@@ -973,6 +1077,7 @@ confirmation_succeeded:
return 0;
confirmation_failed:
+ dccp_pr_debug("Confirmation failed\n");
return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR
: DCCP_RESET_CODE_OPTION_ERROR;
}
@@ -1151,6 +1256,8 @@ int dccp_feat_activate_values(struct soc
return 0;
activation_failed:
+ dccp_pr_debug("Activation of %s failed\n", idx < 0 ? "unknown feature" :
+ dccp_feat_fname(dccp_feat_table[idx].feat_num));
/*
* We clean up everything that may have been allocated, since
* it is difficult to track at which stage negotiation failed.
@@ -1164,47 +1271,3 @@ activation_failed:
dp->dccps_hc_rx_ackvec = NULL;
return -1;
}
-
-#ifdef CONFIG_IP_DCCP_DEBUG
-const char *dccp_feat_typename(const u8 type)
-{
- switch(type) {
- case DCCPO_CHANGE_L: return("ChangeL");
- case DCCPO_CONFIRM_L: return("ConfirmL");
- case DCCPO_CHANGE_R: return("ChangeR");
- case DCCPO_CONFIRM_R: return("ConfirmR");
- /* the following case must not appear in feature negotation */
- default: dccp_pr_debug("unknown type %d [BUG!]\n", type);
- }
- return NULL;
-}
-
-EXPORT_SYMBOL_GPL(dccp_feat_typename);
-
-const char *dccp_feat_name(const u8 feat)
-{
- static const char *feature_names[] = {
- [DCCPF_RESERVED] = "Reserved",
- [DCCPF_CCID] = "CCID",
- [DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos",
- [DCCPF_SEQUENCE_WINDOW] = "Sequence Window",
- [DCCPF_ECN_INCAPABLE] = "ECN Incapable",
- [DCCPF_ACK_RATIO] = "Ack Ratio",
- [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector",
- [DCCPF_SEND_NDP_COUNT] = "Send NDP Count",
- [DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage",
- [DCCPF_DATA_CHECKSUM] = "Send Data Checksum",
- };
- if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
- return feature_names[DCCPF_RESERVED];
-
- if (feat == DCCPF_SEND_LEV_RATE)
- return "Send Loss Event Rate";
- if (feat >= DCCPF_MIN_CCID_SPECIFIC)
- return "CCID-specific";
-
- return feature_names[feat];
-}
-
-EXPORT_SYMBOL_GPL(dccp_feat_name);
-#endif /* CONFIG_IP_DCCP_DEBUG */
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -484,10 +484,6 @@ int dccp_insert_fn_opt(struct sk_buff *s
*to++ = *val;
if (len)
memcpy(to, val, len);
-
- dccp_pr_debug("%s(%s (%d), ...), length %d\n",
- dccp_feat_typename(type),
- dccp_feat_name(feat), feat, len);
return 0;
}
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -97,19 +97,6 @@ extern int sysctl_dccp_feat_rx_ccid;
extern int sysctl_dccp_feat_tx_ccid;
extern int sysctl_dccp_feat_send_ndp_count;
-#ifdef CONFIG_IP_DCCP_DEBUG
-extern const char *dccp_feat_typename(const u8 type);
-extern const char *dccp_feat_name(const u8 feat);
-
-static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
-{
- dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type),
- dccp_feat_name(feat), feat, val);
-}
-#else
-#define dccp_feat_debug(type, feat, val)
-#endif /* CONFIG_IP_DCCP_DEBUG */
-
extern int dccp_feat_init(struct sock *sk);
extern void dccp_feat_initialise_sysctls(void);
extern int dccp_feat_register_change(struct sock *sk, u8 feat,
-
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