[sr-dev] git:master: registrar: randomize expires value received from UAC

Module: sip-router Branch: master Commit: ba0cf0014908645e6b17b6e305e2e1ae4235a94f URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=ba0cf00… Author: Alekzander Spiridonov &lt;sipidronov(a)gmail.com&gt; Committer: Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; 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; } }