Re: snmpd: engine id is just a binary string?

[Gerhard Roth]

On Fri, 28 Jul 2017 12:39:48 + Florian Obser  wrote:
> Not sure about this one, a quick glance at RFC 3411 suggests this
> is just a binary string, so uint8_t is more appropriate.
> 
> Any snmp nerds around?
> 
> clang complained about this:
> 
> /usr/src/usr.sbin/snmpd/snmpd.c:349:47: warning: implicit conversion from 
> 'int' to 'char' changes value from 128 to -128 [-Wconstant-conversion]
> env->sc_engineid[(env->sc_engineid_len)++] = SNMP_ENGINEID_FMT_EID;
>~ ^
> /usr/src/usr.sbin/snmpd/snmpd.h:80:31: note: expanded from macro 
> 'SNMP_ENGINEID_FMT_EID'
> ^~~
> 
> diff --git snmpd/snmpd.h snmpd/snmpd.h
> index 91186f23e42..ce1902bdc03 100644
> --- snmpd/snmpd.h
> +++ snmpd/snmpd.h
> @@ -438,7 +438,7 @@ struct snmp_message {
>   long longsm_secmodel;
>   u_int32_tsm_engine_boots;
>   u_int32_tsm_engine_time;
> - char sm_ctxengineid[SNMPD_MAXENGINEIDLEN];
> + uint8_t  sm_ctxengineid[SNMPD_MAXENGINEIDLEN];
>   size_t   sm_ctxengineid_len;
>   char sm_ctxname[SNMPD_MAXCONTEXNAMELEN+1];
>  
> @@ -574,7 +574,7 @@ struct snmpd {
>   char sc_rwcommunity[SNMPD_MAXCOMMUNITYLEN];
>   char sc_trcommunity[SNMPD_MAXCOMMUNITYLEN];
>  
> - char sc_engineid[SNMPD_MAXENGINEIDLEN];
> + uint8_t  sc_engineid[SNMPD_MAXENGINEIDLEN];
>   size_t   sc_engineid_len;
>  
>   struct snmp_statssc_stats;
> 

Looks good, ok gerhard@

snmpd: engine id is just a binary string?

[Florian Obser]

Not sure about this one, a quick glance at RFC 3411 suggests this
is just a binary string, so uint8_t is more appropriate.

Any snmp nerds around?

clang complained about this:

/usr/src/usr.sbin/snmpd/snmpd.c:349:47: warning: implicit conversion from 'int' 
to 'char' changes value from 128 to -128 [-Wconstant-conversion]
env->sc_engineid[(env->sc_engineid_len)++] = SNMP_ENGINEID_FMT_EID;
   ~ ^
/usr/src/usr.sbin/snmpd/snmpd.h:80:31: note: expanded from macro 
'SNMP_ENGINEID_FMT_EID'
^~~

diff --git snmpd/snmpd.h snmpd/snmpd.h
index 91186f23e42..ce1902bdc03 100644
--- snmpd/snmpd.h
+++ snmpd/snmpd.h
@@ -438,7 +438,7 @@ struct snmp_message {
long longsm_secmodel;
u_int32_tsm_engine_boots;
u_int32_tsm_engine_time;
-   char sm_ctxengineid[SNMPD_MAXENGINEIDLEN];
+   uint8_t  sm_ctxengineid[SNMPD_MAXENGINEIDLEN];
size_t   sm_ctxengineid_len;
char sm_ctxname[SNMPD_MAXCONTEXNAMELEN+1];
 
@@ -574,7 +574,7 @@ struct snmpd {
char sc_rwcommunity[SNMPD_MAXCOMMUNITYLEN];
char sc_trcommunity[SNMPD_MAXCOMMUNITYLEN];
 
-   char sc_engineid[SNMPD_MAXENGINEIDLEN];
+   uint8_t  sc_engineid[SNMPD_MAXENGINEIDLEN];
size_t   sc_engineid_len;
 
struct snmp_statssc_stats;

-- 
I'm not entirely sure you are real.