ref: b502a62da2ec6058923db94f87ecc2d29db2fa77
dir: /os/port/devdynld.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include <a.out.h> #include <dynld.h> #include <kernel.h> /* * TO DO * - dynamic allocation of Dev.dc * - inter-module dependencies * - reference count on Dev to allow error("inuse") [or how else to do it] * - is Dev.shutdown the right function to call? Dev.config perhaps? */ #define DBG if(1) print #define NATIVE extern ulong ndevs; enum { Qdir, Qdynld, Qdynsyms, DEVCHAR = 'L', }; static Dirtab dltab[] = { ".", {Qdir, 0, QTDIR}, 0, DMDIR|0555, "dynld", {Qdynld}, 0, 0644, "dynsyms", {Qdynsyms}, 0, 0444, }; typedef struct Dyndev Dyndev; struct Dyndev { char* name; /* device name (eg, "dynld") */ char* tag; /* version tag (eg, MD5 or SHA1 hash of content) */ char* path; /* file from whence it came */ Dynobj* o; Dev* dev; Dyndev* next; }; static Dyndev *loaded; static QLock dllock; static Dyndev** finddyndev(char*); static int matched(Dyndev*, char*, char*); extern Dynobj* kdynloadfd(int, Dynsym*, int, ulong); static void dlfree(Dyndev *l) { if(l != nil){ free(l->tag); free(l->name); free(l->path); dynobjfree(l->o); free(l); } } static Dyndev* dlload(char *path, Dynsym *tab, int ntab) { Dyndev *l; int fd; /* in Plan 9, would probably use Chan* interface here */ fd = kopen(path, OREAD); if(fd < 0) error("cannot open"); if(waserror()){ kclose(fd); nexterror(); } l = mallocz(sizeof(Dyndev), 1); if(l == nil) error(Enomem); if(waserror()){ dlfree(l); nexterror(); } l->path = strdup(path); if(l->path == nil) error(Enomem); l->o = kdynloadfd(fd, tab, ntab, 0); if(l->o == nil) error(up->env->errstr); poperror(); poperror(); kclose(fd); return l; } static void devload(char *name, char *path, char *tag) { int i; Dyndev *l, **lp; Dev *dev; char tabname[32]; lp = finddyndev(name); if(*lp != nil) error("already loaded"); /* i'm assuming the name (eg, "cons") is to be unique */ l = dlload(path, _exporttab, dyntabsize(_exporttab)); if(waserror()){ dlfree(l); nexterror(); } snprint(tabname, sizeof(tabname), "%sdevtab", name); dev = dynimport(l->o, tabname, signof(*dev)); if(dev == nil) errorf("can't find %sdevtab in module", name); kstrdup(&l->name, name); kstrdup(&l->tag, tag != nil? tag: ""); if(dev->name == nil) dev->name = l->name; else if(strcmp(dev->name, l->name) != 0) errorf("module file has device %s", dev->name); /* TO DO: allocate dev->dc dynamically (cf. brucee's driver) */ if(devno(dev->dc, 1) >= 0) errorf("devchar %C already used", dev->dc); for(i = 0; devtab[i] != nil; i++) ; if(i >= ndevs || devtab[i+1] != nil) error("device table full"); #ifdef NATIVE i = splhi(); dev->reset(); splx(i); #endif dev->init(); l->dev = devtab[i] = dev; l->next = loaded; loaded = l; /* recently loaded ones first: good unload order? */ poperror(); } static Dyndev** finddyndev(char *name) { Dyndev *l, **lp; for(lp = &loaded; (l = *lp) != nil; lp = &l->next) if(strcmp(l->name, name) == 0) break; return lp; } static int matched(Dyndev *l, char *path, char *tag) { if(path != nil && strcmp(l->path, path) != 0) return 0; if(tag != nil && strcmp(l->tag, tag) != 0) return 0; return 1; } static void devunload(char *name, char *path, char *tag) { int i; Dyndev *l, **lp; lp = finddyndev(name); l = *lp; if(l == nil) error("not loaded"); if(!matched(l, path, tag)) error("path/tag mismatch"); for(i = 0; i < ndevs; i++) if(l->dev == devtab[i]){ devtab[i] = nil; /* TO DO: ensure driver is not currently in use */ break; } #ifdef NATIVE l->dev->shutdown(); #endif *lp = l->next; dlfree(l); } static long readdynld(void *a, ulong n, ulong offset) { char *p; Dyndev *l; int m, len; m = 0; for(l = loaded; l != nil; l = l->next) m += 48 + strlen(l->name) + strlen(l->path) + strlen(l->tag); p = malloc(m); if(p == nil) error(Enomem); if(waserror()){ free(p); nexterror(); } *p = 0; len = 0; for(l = loaded; l != nil; l = l->next) if(l->dev) len += snprint(p+len, m-len, "#%C\t%.8p\t%.8lud\t%q\t%q\t%q\n", l->dev->dc, l->o->base, l->o->size, l->name, l->path, l->tag); n = readstr(offset, a, n, p); poperror(); free(p); return n; } static long readsyms(char *a, ulong n, ulong offset) { char *p; Dynsym *t; long l, nr; p = malloc(READSTR); if(p == nil) error(Enomem); if(waserror()){ free(p); nexterror(); } nr = 0; for(t = _exporttab; n > 0 && t->name != nil; t++){ l = snprint(p, READSTR, "%.8lux %.8lux %s\n", t->addr, t->sig, t->name); if(offset >= l){ offset -= l; continue; } l = readstr(offset, a, n, p); offset = 0; n -= l; a += l; nr += l; } poperror(); free(p); return nr; } static Chan* dlattach(char *spec) { return devattach(DEVCHAR, spec); } static Walkqid* dlwalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name, nname, dltab, nelem(dltab), devgen); } static int dlstat(Chan *c, uchar *db, int n) { return devstat(c, db, n, dltab, nelem(dltab), devgen); } static Chan* dlopen(Chan *c, int omode) { return devopen(c, omode, dltab, nelem(dltab), devgen); } static void dlclose(Chan *c) { USED(c); } static long dlread(Chan *c, void *a, long n, vlong voffset) { switch((u64)c->qid.path){ case Qdir: return devdirread(c, a, n, dltab, nelem(dltab), devgen); case Qdynld: return readdynld(a, n, voffset); case Qdynsyms: return readsyms(a, n, voffset); default: error(Egreg); } return n; } static long dlwrite(Chan *c, void *a, long n, vlong voffset) { Cmdbuf *cb; char *name, *tag, *path; USED(voffset); switch((u64)c->qid.path){ case Qdynld: cb = parsecmd(a, n); qlock(&dllock); if(waserror()){ qunlock(&dllock); free(cb); nexterror(); } if(cb->nf < 3 || strcmp(cb->f[1], "dev") != 0) /* only do devices */ cmderror(cb, Ebadctl); name = cb->f[2]; path = nil; if(cb->nf > 3) path = cb->f[3]; tag = nil; if(cb->nf > 4) tag = cb->f[4]; if(strcmp(cb->f[0], "load") == 0){ if(path == nil) cmderror(cb, "missing load path"); devload(name, path, tag); /* TO DO: remaining parameters might be dependencies? */ }else if(strcmp(cb->f[0], "unload") == 0) devunload(name, path, tag); else cmderror(cb, Ebadctl); poperror(); qunlock(&dllock); free(cb); break; default: error(Egreg); } return n; } Dev dynlddevtab = { DEVCHAR, "dynld", devreset, devinit, devshutdown, /* TO DO */ dlattach, dlwalk, dlstat, dlopen, devcreate, dlclose, dlread, devbread, dlwrite, devbwrite, devremove, devwstat, };