ref: a920c765f2b4130590fb5971a50690b21664957a
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((ulong)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((ulong)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,
};