Re: [Suggestion] net/tipc: can delete checking: (if_local_len > TIPC_MAX_IF_NAME) || (if_peer_len > TIPC_MAX_IF_NAME)

[Chen Gang <gang.chen@asianux.com>]

于 2012年11月20日 13:19, Xue Ying 写道:
> Chen Gang wrote:
>> Hello David Miller:
>>
>>   at net/tipc/link.c:212,213, we can delete the check (if_local_len > TIPC_MAX_IF_NAME) and (if_peer_len  > TIPC_MAX_IF_NAME)
>>   for the total buffer length is no more than TIPC_MAX_IF_NAME, already (at line 182..186).
>>
>>   
> 
> The length of name_copy array is TIPC_MAX_LINK_NAME(i.e, 60) while
> TIPC_MAX_IF_NAME is defined to 16, why does the former is more than the
> latter?
> 
> Regards,
> Ying
> 

  It is my fault. thanks.

  Regards,

  gchen


>>   suggest to modify it, although it is minor.
>>
>> thanks.
>>
>>
>>  167 static int link_name_validate(const char *name,
>>  168                                 struct tipc_link_name *name_parts)
>>  169 {
>>  170         char name_copy[TIPC_MAX_LINK_NAME];
>>  171         char *addr_local;
>>  172         char *if_local;
>>  173         char *addr_peer;
>>  174         char *if_peer;
>>  175         char dummy;
>>  176         u32 z_local, c_local, n_local;
>>  177         u32 z_peer, c_peer, n_peer;
>>  178         u32 if_local_len;
>>  179         u32 if_peer_len;
>>  180 
>>  181         /* copy link name & ensure length is OK */
>>  182         name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
>>  183         /* need above in case non-Posix strncpy() doesn't pad with nulls */
>>  184         strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
>>  185         if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
>>  186                 return 0;
>>  187 
>>  188         /* ensure all component parts of link name are present */
>>  189         addr_local = name_copy;
>>  190         if_local = strchr(addr_local, ':');
>>  191         if (if_local == NULL)
>>  192                 return 0;
>>  193         *(if_local++) = 0;
>>  194         addr_peer = strchr(if_local, '-');
>>  195         if (addr_peer == NULL)
>>  196                 return 0;
>>  197         *(addr_peer++) = 0;
>>  198         if_local_len = addr_peer - if_local;
>>  199         if_peer = strchr(addr_peer, ':');
>>  200         if (if_peer == NULL)
>>  201                 return 0;
>>  202         *(if_peer++) = 0;
>>  203         if_peer_len = strlen(if_peer) + 1;
>>  204 
>>  205         /* validate component parts of link name */
>>  206         if ((sscanf(addr_local, "%u.%u.%u%c",
>>  207                     &z_local, &c_local, &n_local, &dummy) != 3) ||
>>  208             (sscanf(addr_peer, "%u.%u.%u%c",
>>  209                     &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
>>  210             (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
>>  211             (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
>>  212             (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
>>  213             (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME))
>>  214                 return 0;
>>  215 
>>  216         /* return link name components, if necessary */
>>  217         if (name_parts) {
>>  218                 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
>>  219                 strcpy(name_parts->if_local, if_local);
>>  220                 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
>>  221                 strcpy(name_parts->if_peer, if_peer);
>>  222         }
>>  223         return 1;
>>  224 }
>>
>>
>>
>>   
> 
> 
> 


-- 
Chen Gang

Asianux Corporation