[sr-dev] git:master: registrar: randomize expires value received from UAC
Daniel-Constantin Mierla
miconda at gmail.com
Tue Aug 26 13:04:22 CEST 2014
Module: sip-router
Branch: master
Commit: ba0cf0014908645e6b17b6e305e2e1ae4235a94f
URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=ba0cf0014908645e6b17b6e305e2e1ae4235a94f
Author: Alekzander Spiridonov <sipidronov at gmail.com>
Committer: Daniel-Constantin Mierla <miconda at gmail.com>
Date: Fri Aug 22 05:20:42 2014 -0700
registrar: randomize expires value received from UAC
---
modules/registrar/doc/registrar_admin.xml | 11 ++--
modules/registrar/sip_msg.c | 77 ++++++++++++++++-------------
2 files changed, 48 insertions(+), 40 deletions(-)
diff --git a/modules/registrar/doc/registrar_admin.xml b/modules/registrar/doc/registrar_admin.xml
index 4cd2053..992e5fb 100644
--- a/modules/registrar/doc/registrar_admin.xml
+++ b/modules/registrar/doc/registrar_admin.xml
@@ -157,10 +157,9 @@ modparam("registrar", "default_expires", 1800)
<title><varname>default_expires_range</varname> (integer)</title>
<para>
This parameter specifies that the expiry used for newly created usrloc records
- are not fixed(when <quote>default_expires</quote> applies), but a random value in the interval
- <quote>[default_expires-default_expires_range%, default_expires+default_expires_range%]</quote>.
- The value is between 0 and 100 and represent the maximim percentage from default_expires that
- will be substracted or added when computing the value. Default in 0, meaning default_expires
+ are not fixed, but a random value in the interval <quote>[default_expires-default_expires_range%, default_expires]</quote>.
+ The value is between 0 and 100 and represent the maximim percentage from expires that
+ will be substracted when computing the value. Default in 0, meaning default_expires
is left unmodified. This parameter can be modified via ser config framework.
</para>
<para>
@@ -181,8 +180,8 @@ modparam("registrar", "default_expires_range", 30) # +- 30% from default_expires
<title><varname>expires_range</varname> (integer)</title>
<para>
Similar to default_expires_range, but it applies to the incoming expires
- value and it only lowers the value. Default in 0, meaning the expires
- is left unmodified. This parameter can be modified via config framework.
+ value. Default in 0, meaning the expires is left unmodified.
+ This parameter can be modified via config framework.
</para>
<para>
<emphasis>
diff --git a/modules/registrar/sip_msg.c b/modules/registrar/sip_msg.c
index 19ea3df..f5a84f2 100644
--- a/modules/registrar/sip_msg.c
+++ b/modules/registrar/sip_msg.c
@@ -44,45 +44,37 @@
static struct hdr_field* act_contact;
-/*! \brief
- * Return an expire value in the range [ default_expires - range%, default_expires + range% ]
+/* \brief
+ * Return randomized expires between expires-range% and expires.
+ * RFC allows only value less or equal to the one provided by UAC.
*/
-static inline int get_expire_val(void)
+static inline int randomize_expires( int expires, int range )
{
- int expires = cfg_get(registrar, registrar_cfg, default_expires);
- int range = cfg_get(registrar, registrar_cfg, default_expires_range);
- /* if no range is given just return default_expires */
- if(range == 0) return expires;
- /* select a random value in the range */
- return expires - (float)range/100 * expires + (float)(rand()%100)/100 * 2 * (float)range/100 * expires;
+ /* if no range is given just return expires */
+ if(range == 0) return expires;
+
+ int range_min = expires - (float)range/100 * expires;
+
+ return range_min + (float)(rand()%100)/100 * ( expires - range_min );
}
/*! \brief
* Return value of Expires header field
- * if the HF exists converted to absolute
- * time, if the HF doesn't exist, returns
- * default value;
+ * if the HF exists, if the HF doesn't exist,
+ * returns -1;
*/
static inline int get_expires_hf(struct sip_msg* _m)
{
exp_body_t* p;
- int range;
+
if (_m->expires) {
p = (exp_body_t*)_m->expires->parsed;
if (p->valid) {
- if (p->val != 0) {
- range = cfg_get(registrar, registrar_cfg, default_expires_range);
- if(likely(range==0))
- return p->val + act_time;
- return p->val + act_time - (float)range/100 * p->val
- + ((float)(rand()%100)/100) * ((float)range/100 * p->val);
- } else return 0;
- } else {
- return act_time + get_expire_val();
+ return p->val;
}
- } else
- return act_time + get_expire_val();
+ }
+ return -1;
}
@@ -159,7 +151,7 @@ int check_contacts(struct sip_msg* _m, int* _s)
if (((contact_body_t*)_m->contact->parsed)->star == 1) {
/* The first Contact HF is star */
/* Expires must be zero */
- if (get_expires_hf(_m) > 0) {
+ if (get_expires_hf(_m) != 0) {
rerrno = R_STAR_EXP;
return 1;
}
@@ -252,22 +244,39 @@ contact_t* get_next_contact(contact_t* _c)
*/
void calc_contact_expires(struct sip_msg* _m, param_t* _ep, int* _e)
{
+ int range = 0;
if (!_ep || !_ep->body.len) {
- *_e = get_expires_hf(_m);
+ *_e = get_expires_hf(_m);
+
+ if ( *_e < 0 ) {
+ *_e = cfg_get(registrar, registrar_cfg, default_expires);
+ range = cfg_get(registrar, registrar_cfg, default_expires_range);
+ } else {
+ range = cfg_get(registrar, registrar_cfg, expires_range);
+ }
} else {
if (str2int(&_ep->body, (unsigned int*)_e) < 0) {
- *_e = get_expire_val();
+ *_e = cfg_get(registrar, registrar_cfg, default_expires);
+ range = cfg_get(registrar, registrar_cfg, default_expires_range);
+ } else {
+ range = cfg_get(registrar, registrar_cfg, expires_range);
}
- /* Convert to absolute value */
- if (*_e != 0) *_e += act_time;
}
- if ((*_e != 0) && ((*_e - act_time) < cfg_get(registrar, registrar_cfg, min_expires))) {
- *_e = cfg_get(registrar, registrar_cfg, min_expires) + act_time;
- }
+ if ( *_e != 0 )
+ {
+ *_e = randomize_expires( *_e, range );
+
+ if (*_e < cfg_get(registrar, registrar_cfg, min_expires)) {
+ *_e = cfg_get(registrar, registrar_cfg, min_expires);
+ }
+
+ if (cfg_get(registrar, registrar_cfg, max_expires) && (*_e > cfg_get(registrar, registrar_cfg, max_expires))) {
+ *_e = cfg_get(registrar, registrar_cfg, max_expires);
+ }
- if ((*_e != 0) && cfg_get(registrar, registrar_cfg, max_expires) && ((*_e - act_time) > cfg_get(registrar, registrar_cfg, max_expires))) {
- *_e = cfg_get(registrar, registrar_cfg, max_expires) + act_time;
+ /* Convert to absolute value */
+ *_e += act_time;
}
}
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