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dccp: Debugging functions for feature negotiation
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Since all feature-negotiation processing now takes place in feat.c, functions
for producing verbose debugging output are concentrated there.

New functions to print out values, entry records, and options are provided,
and also a macro is defined to not always have the function name in the
output line.

Thanks a lot to Wei Yongjun and Giuseppe Galeota for help with errors in an
earlier revision of this patch.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
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Gerrit Renker committed Sep 4, 2008
1 parent 0a48226 commit 76f738a
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Showing 4 changed files with 109 additions and 63 deletions.
2 changes: 2 additions & 0 deletions net/dccp/dccp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
153 changes: 107 additions & 46 deletions net/dccp/feat.c
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Original file line number Diff line number Diff line change
Expand Up @@ -204,6 +204,100 @@ static int dccp_feat_default_value(u8 feat_num)
return idx < 0 ? : dccp_feat_table[idx].default_value;
}

/*
* Debugging and verbose-printing section
*/
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 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 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) do { \
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 ? "!" : ""); } while (0)

#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, val, len, 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)
{
Expand Down Expand Up @@ -236,6 +330,10 @@ static int __dccp_feat_activate(struct sock *sk, const int idx,
/* 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);
}

Expand Down Expand Up @@ -539,6 +637,7 @@ int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq,
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;
Expand Down Expand Up @@ -792,6 +891,7 @@ int dccp_feat_finalise_settings(struct dccp_sock *dp)
while (i--)
if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i))
return -1;
dccp_feat_print_fnlist(fn);
return 0;
}

Expand Down Expand Up @@ -910,6 +1010,8 @@ static u8 dccp_feat_change_recv(struct list_head *fn, u8 is_mandatory, u8 opt,
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 look up in the list.
Expand Down Expand Up @@ -1015,6 +1117,8 @@ static u8 dccp_feat_confirm_recv(struct list_head *fn, u8 is_mandatory, u8 opt,
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;
Expand Down Expand Up @@ -1217,9 +1321,10 @@ int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list)
goto activation_failed;
}
if (cur->state != FEAT_STABLE) {
DCCP_CRIT("Negotiation of %s %u failed in state %u",
DCCP_CRIT("Negotiation of %s %s failed in state %s",
cur->is_local ? "local" : "remote",
cur->feat_num, cur->state);
dccp_feat_fname(cur->feat_num),
dccp_feat_sname[cur->state]);
goto activation_failed;
}
fvals[idx][cur->is_local] = &cur->val;
Expand Down Expand Up @@ -1260,47 +1365,3 @@ int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list)
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 */
13 changes: 0 additions & 13 deletions net/dccp/feat.h
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Original file line number Diff line number Diff line change
Expand Up @@ -106,19 +106,6 @@ extern unsigned long sysctl_dccp_sequence_window;
extern int sysctl_dccp_rx_ccid;
extern int sysctl_dccp_tx_ccid;

#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_sp(struct sock *sk, u8 feat, u8 is_local,
Expand Down
4 changes: 0 additions & 4 deletions net/dccp/options.c
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Original file line number Diff line number Diff line change
Expand Up @@ -498,10 +498,6 @@ int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
*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;
}

Expand Down

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