Hello Michael, Am 10.01.2014 18:52, schrieb Michael Kerrisk (man-pages): > On 01/10/2014 12:30 PM, Tilman Schmidt wrote: >> Add the missing description of the possibility to call SIOCGIFCONF >> with ifc_req==NULL to determine the needed buffer size, as described >> in http://lkml.indiana.edu/hypermail/linux/kernel/0110.1/0506.html >> and verified against source files net/core/dev_ioctl.c and >> net/ipv4/devinet.c in the current kernel git tree. [...]> > Thanks for the patch. I'm trying to verify this from the code, but > am having some trouble finding the relevant pieces. Could you point > me more specifically at the points in the kernel source where this > case is handled? Gladly. Function dev_ifconf() [net/core/dev_ioctl.c line 67ff.] is the main handler for SIOCGIFCONF. It calls the registered protocol specific handlers via the table gifconf_list[]. The current kernel has only one such handler, inet_gifconf() [net/ipv4/devinet.c line 1115ff.] If ifc.ifc_buf is NULL, dev_ifconf() calls the protocol specific handlers with NULL as second argument. [net/core/dev_ioctl.c line 96] If inet_gifconf() is called with NULL as second argument it just adds up the data sizes, skipping the size check and data transfer. [net/ipv4/devinet.c line 1127f.] Best regards, Tilman -- Tilman Schmidt E-Mail: tilman@xxxxxxx Bonn, Germany Diese Nachricht besteht zu 100% aus wiederverwerteten Bits. Ungeöffnet mindestens haltbar bis: (siehe Rückseite) -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
