ref: 38ea1ac105f4484f02bba3bfbc790ebe4f18f016
dir: /sys/src/cmd/archfs.c/
/* * archfs - mount mkfs style archives */ #include <u.h> #include <libc.h> #include <bio.h> #include <auth.h> #include <fcall.h> #include <thread.h> #include <9p.h> Tree *archtree; Biobuf *b; int verbose; typedef struct Ahdr Ahdr; struct Ahdr { char *name; Dir; }; typedef struct Arch Arch; struct Arch { vlong off; vlong length; }; static void* emalloc(long sz) { void *v; v = malloc(sz); if(v == nil) sysfatal("malloc %lud fails", sz); memset(v, 0, sz); return v; } static char* estrdup(char *s) { s = strdup(s); if(s == nil) sysfatal("strdup (%.10s) fails", s); return s; } static char* Bgetline(Biobuf *b) { char *p; if(p = Brdline(b, '\n')) p[Blinelen(b)-1] = '\0'; return p; } Ahdr* gethdr(Biobuf *b) { Ahdr *a; char *p, *f[10]; if((p = Bgetline(b)) == nil) return nil; if(strcmp(p, "end of archive") == 0) { werrstr(""); return nil; } if(tokenize(p, f, nelem(f)) != 6) { werrstr("bad format"); return nil; } a = emalloc(sizeof(*a)); a->name = estrdup(f[0]); a->mode = strtoul(f[1], 0, 8); a->uid = estrdup(f[2]); a->gid = estrdup(f[3]); a->mtime = strtoll(f[4], 0, 10); a->length = strtoll(f[5], 0, 10); return a; } static Arch* newarch(vlong off, vlong length) { static Arch *abuf; static int nabuf; if(nabuf == 0) { nabuf = 256; abuf = emalloc(sizeof(Arch)*nabuf); } nabuf--; abuf->off = off; abuf->length = length; return abuf++; } static File* createpath(File *f, char *name, char *u, ulong m) { char *p; File *nf; if(verbose) fprint(2, "createpath %s\n", name); incref(f); while(f && (p = strchr(name, '/'))) { *p = '\0'; if(strcmp(name, "") != 0 && strcmp(name, ".") != 0){ /* this would be a race if we were multithreaded */ incref(f); /* so walk doesn't kill it immediately on failure */ if((nf = walkfile(f, name)) == nil) nf = createfile(f, name, u, DMDIR|0777, nil); decref(f); f = nf; } *p = '/'; name = p+1; } if(f == nil) return nil; incref(f); if((nf = walkfile(f, name)) == nil) nf = createfile(f, name, u, m, nil); decref(f); return nf; } static void archcreatefile(char *name, Arch *arch, Dir *d) { File *f; f = createpath(archtree->root, name, d->uid, d->mode); if(f == nil) sysfatal("creating %s: %r", name); free(f->gid); f->gid = estrdup9p(d->gid); f->aux = arch; f->mtime = d->mtime; f->length = d->length; decref(f); } static void fsread(Req *r) { Arch *a; char err[ERRMAX]; int n; a = r->fid->file->aux; if(a->length <= r->ifcall.offset) r->ifcall.count = 0; else if(a->length <= r->ifcall.offset+r->ifcall.count) r->ifcall.count = a->length - r->ifcall.offset; werrstr("unknown error"); if(Bseek(b, a->off+r->ifcall.offset, 0) < 0 || (n = Bread(b, r->ofcall.data, r->ifcall.count)) < 0) { err[0] = '\0'; errstr(err, sizeof err); respond(r, err); } else { r->ofcall.count = n; respond(r, nil); } } Srv fs = { .read= fsread, }; static void usage(void) { fprint(2, "usage: archfs [-abcC] [-m mtpt] archfile\n"); exits("usage"); } void main(int argc, char **argv) { Ahdr *a; ulong flag; char *mtpt; char err[ERRMAX]; flag = 0; mtpt = "/mnt/arch"; ARGBEGIN{ case 'D': chatty9p++; break; case 'a': flag |= MAFTER; break; case 'b': flag |= MBEFORE; break; case 'c': flag |= MCREATE; break; case 'C': flag |= MCACHE; break; case 'm': mtpt = EARGF(usage()); break; default: usage(); break; }ARGEND; if(argc != 1) usage(); if((b = Bopen(argv[0], OREAD)) == nil) sysfatal("open '%s': %r", argv[0]); archtree = fs.tree = alloctree("sys", "sys", DMDIR|0775, nil); while(a = gethdr(b)) { archcreatefile(a->name, newarch(Boffset(b), a->length), a); Bseek(b, a->length, 1); } err[0] = '\0'; errstr(err, sizeof err); if(err[0]) sysfatal("reading archive: %s", err); postmountsrv(&fs, nil, mtpt, flag); exits(0); }