ref: 595fbddb1c9e152d9080d7b0faa301709fa6466d
dir: /sys/src/9/ip/netdevmedium.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "ip.h" static void netdevbind(Ipifc *ifc, int argc, char **argv); static void netdevunbind(Ipifc *ifc); static void netdevbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip); static void netdevread(void *a); typedef struct Netdevrock Netdevrock; struct Netdevrock { Fs *f; /* file system we belong to */ Proc *readp; /* reading process */ Chan *mchan; /* Data channel */ }; Medium netdevmedium = { .name= "netdev", .hsize= 0, .mintu= 0, .maxtu= 64000, .maclen= 0, .bind= netdevbind, .unbind= netdevunbind, .bwrite= netdevbwrite, .unbindonclose= 0, }; /* * called to bind an IP ifc to a generic network device * called with ifc qlock'd */ static void netdevbind(Ipifc *ifc, int argc, char **argv) { Chan *mchan; Netdevrock *er; if(argc < 2) error(Ebadarg); mchan = namec(argv[2], Aopen, ORDWR, 0); er = smalloc(sizeof(*er)); er->mchan = mchan; er->f = ifc->conv->p->f; ifc->arg = er; kproc("netdevread", netdevread, ifc); } /* * called with ifc wlock'd */ static void netdevunbind(Ipifc *ifc) { Netdevrock *er = ifc->arg; if(er->readp != nil) postnote(er->readp, 1, "unbind", 0); /* wait for readers to die */ while(er->readp != nil) tsleep(&up->sleep, return0, 0, 300); if(er->mchan != nil) cclose(er->mchan); free(er); } /* * called by ipoput with a single block to write */ static void netdevbwrite(Ipifc *ifc, Block *bp, int, uchar*) { Netdevrock *er = ifc->arg; if(BLEN(bp) < ifc->mintu) bp = adjustblock(bp, ifc->mintu); devtab[er->mchan->type]->bwrite(er->mchan, bp, 0); ifc->out++; } /* * process to read from the device */ static void netdevread(void *a) { Ipifc *ifc; Block *bp; Netdevrock *er; char *argv[1]; ifc = a; er = ifc->arg; er->readp = up; /* hide identity under a rock for unbind */ if(waserror()){ er->readp = nil; pexit("hangup", 1); } for(;;){ bp = devtab[er->mchan->type]->bread(er->mchan, ifc->maxtu, 0); if(bp == nil){ /* * get here if mchan is a pipe and other side hangs up * clean up this interface & get out */ poperror(); er->readp = nil; argv[0] = "unbind"; if(!waserror()) ifc->conv->p->ctl(ifc->conv, argv, 1); pexit("hangup", 1); } if(!canrlock(ifc)){ freeb(bp); continue; } if(waserror()){ runlock(ifc); nexterror(); } ifc->in++; if(ifc->lifc == nil) freeb(bp); else ipiput4(er->f, ifc, bp); runlock(ifc); poperror(); } } void netdevmediumlink(void) { addipmedium(&netdevmedium); }