88f91a4188
limiting the number of rx buffers an rtw may allocate. Use this sysctl to test the code that copes with buffer exhaustion. Allocate at most RTW_RXQLEN rx buffers, stopping at the sysctl limit. Record in sc_nrxdesc how many were allocated, and put the end-of-ring indication on sc_rxdesc[sc_nrxdesc - 1]. In rtw_init, if no rx buffers could be allocated, log a complaint, clear IFF_RUNNING, and exit with an error. Many changes to accomodate a short rx ring, mainly of the "add a rx-ring length argument" variety. XXX I really should consolidate all of the rx ring variables in one struct and pass that to the rx-ring subroutines. Bug fix: after calling MCLGET, use the (m->m_flags & M_EXT) idiom to check for success, instead of m != NULL. Bug fix: at the top of rtw_start, if IFF_RUNNING is not set, or IFF_OACTIVE is, get out.