1769 lines
34 KiB
C
1769 lines
34 KiB
C
#include "u.h"
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#include "../port/lib.h"
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#include "mem.h"
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#include "dat.h"
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#include "fns.h"
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#include "../port/error.h"
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enum
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{
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PATHSLOP = 20,
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PATHMSLOP = 20,
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};
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static struct Chanalloc
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{
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Lock;
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int fid;
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Chan *free;
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Chan *list;
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}chanalloc;
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typedef struct Elemlist Elemlist;
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struct Elemlist
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{
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char *aname; /* original name */
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char *name; /* copy of name, so '/' can be overwritten */
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int nelems;
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char **elems;
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int *off;
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int mustbedir;
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int nerror;
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int prefix;
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};
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char*
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chanpath(Chan *c)
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{
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if(c == nil)
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return "<nil chan>";
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if(c->path == nil)
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return "<nil path>";
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if(c->path->s == nil)
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return "<nil path.s>";
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return c->path->s;
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}
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int
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isdotdot(char *p)
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{
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return p[0]=='.' && p[1]=='.' && p[2]=='\0';
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}
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long
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incref(Ref *r)
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{
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long old, new;
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do {
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old = r->ref;
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new = old+1;
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} while(!cmpswap(&r->ref, old, new));
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return new;
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}
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long
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decref(Ref *r)
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{
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long old, new;
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do {
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old = r->ref;
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if(old <= 0)
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panic("decref pc=%#p", getcallerpc(&r));
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new = old-1;
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} while(!cmpswap(&r->ref, old, new));
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return new;
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}
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/*
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* Rather than strncpy, which zeros the rest of the buffer, kstrcpy
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* truncates if necessary, always zero terminates, does not zero fill,
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* and puts ... at the end of the string if it's too long. Usually used to
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* save a string in up->genbuf;
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*/
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void
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kstrcpy(char *s, char *t, int ns)
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{
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int nt;
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nt = strlen(t);
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if(nt < ns){
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memmove(s, t, nt);
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s[nt] = '\0';
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return;
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}
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/* too long, truncate */
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nt = ns-1;
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memmove(s, t, nt);
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s[nt] = '\0';
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/* append ... if there is space */
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ns -= 4;
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if(ns < 0)
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return;
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/* look for first byte of UTF-8 sequence by skipping continuation bytes */
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while(ns>0 && (s[--ns]&0xC0)==0x80)
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;
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strcpy(s+ns, "...");
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}
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int
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emptystr(char *s)
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{
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if(s == nil)
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return 1;
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if(s[0] == '\0')
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return 1;
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return 0;
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}
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/*
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* Atomically replace *p with copy of s
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*/
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void
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kstrdup(char **p, char *s)
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{
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int n;
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char *t, *prev;
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n = strlen(s);
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/* if it's a user, we can wait for memory; if not, something's very wrong */
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if(up != nil)
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t = smalloc(n+1);
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else{
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t = malloc(n+1);
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if(t == nil)
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panic("kstrdup: no memory");
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}
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setmalloctag(t, getcallerpc(&p));
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memmove(t, s, n);
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t[n] = '\0';
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prev = *p;
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*p = t;
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free(prev);
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}
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void
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chandevreset(void)
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{
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int i;
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todinit(); /* avoid later reentry causing infinite recursion */
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for(i=0; devtab[i] != nil; i++)
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devtab[i]->reset();
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}
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static void closeproc(void*);
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void
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chandevinit(void)
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{
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int i;
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for(i=0; devtab[i] != nil; i++)
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devtab[i]->init();
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kproc("closeproc", closeproc, nil);
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}
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void
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chandevshutdown(void)
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{
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int i;
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/* shutdown in reverse order */
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for(i=0; devtab[i] != nil; i++)
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;
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for(i--; i >= 0; i--)
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devtab[i]->shutdown();
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}
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Chan*
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newchan(void)
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{
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Chan *c;
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lock(&chanalloc);
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c = chanalloc.free;
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if(c != nil){
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chanalloc.free = c->next;
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c->next = nil;
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} else {
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unlock(&chanalloc);
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c = smalloc(sizeof(Chan));
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lock(&chanalloc);
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c->link = chanalloc.list;
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chanalloc.list = c;
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}
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if(c->fid == 0)
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c->fid = ++chanalloc.fid;
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unlock(&chanalloc);
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/* if you get an error before associating with a dev,
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close calls rootclose, a nop */
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c->type = 0;
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c->flag = 0;
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c->ref = 1;
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c->dev = 0;
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c->offset = 0;
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c->devoffset = 0;
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c->iounit = 0;
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c->umh = nil;
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c->umc = nil;
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c->uri = 0;
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c->dri = 0;
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c->dirrock = nil;
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c->nrock = 0;
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c->mrock = 0;
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c->ismtpt = 0;
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c->mcp = nil;
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c->mux = nil;
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c->aux = nil;
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c->mchan = nil;
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memset(&c->mqid, 0, sizeof(c->mqid));
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c->path = nil;
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return c;
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}
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Path*
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newpath(char *s)
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{
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int i;
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Path *p;
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p = smalloc(sizeof(Path));
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i = strlen(s);
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p->len = i;
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p->alen = i+PATHSLOP;
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p->s = smalloc(p->alen);
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memmove(p->s, s, i+1);
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p->ref = 1;
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/*
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* Cannot use newpath for arbitrary names because the mtpt
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* array will not be populated correctly. The names #/ and / are
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* allowed, but other names with / in them draw warnings.
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*/
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if(strchr(s, '/') != nil && strcmp(s, "#/") != 0 && strcmp(s, "/") != 0)
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print("newpath: %s from %#p\n", s, getcallerpc(&s));
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p->mlen = 1;
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p->malen = PATHMSLOP;
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p->mtpt = smalloc(p->malen*sizeof p->mtpt[0]);
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return p;
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}
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static Path*
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copypath(Path *p)
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{
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int i;
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Path *pp;
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pp = smalloc(sizeof(Path));
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pp->ref = 1;
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pp->len = p->len;
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pp->alen = p->alen;
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pp->s = smalloc(p->alen);
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memmove(pp->s, p->s, p->len+1);
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pp->mlen = p->mlen;
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pp->malen = p->malen;
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pp->mtpt = smalloc(p->malen*sizeof pp->mtpt[0]);
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for(i=0; i<pp->mlen; i++){
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pp->mtpt[i] = p->mtpt[i];
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if(pp->mtpt[i] != nil)
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incref(pp->mtpt[i]);
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}
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return pp;
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}
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void
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pathclose(Path *p)
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{
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int i;
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if(p == nil || decref(p))
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return;
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for(i=0; i<p->mlen; i++)
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if(p->mtpt[i] != nil)
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cclose(p->mtpt[i]);
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free(p->mtpt);
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free(p->s);
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free(p);
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}
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/*
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* In place, rewrite name to compress multiple /, eliminate ., and process ..
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* (Really only called to remove a trailing .. that has been added.
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* Otherwise would need to update n->mtpt as well.)
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*/
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static void
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fixdotdotname(Path *p)
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{
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char *r;
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if(p->s[0] == '#'){
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r = strchr(p->s, '/');
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if(r == nil)
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return;
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cleanname(r);
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/*
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* The correct name is #i rather than #i/,
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* but the correct name of #/ is #/.
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*/
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if(strcmp(r, "/")==0 && p->s[1] != '/')
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*r = '\0';
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}else
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cleanname(p->s);
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p->len = strlen(p->s);
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}
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static Path*
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uniquepath(Path *p)
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{
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Path *new;
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if(p->ref > 1){
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/* copy on write */
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new = copypath(p);
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pathclose(p);
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p = new;
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}
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return p;
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}
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static Path*
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addelem(Path *p, char *s, Chan *from)
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{
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char *t;
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int a, i;
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Chan *c, **tt;
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if(s[0]=='.' && s[1]=='\0')
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return p;
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p = uniquepath(p);
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i = strlen(s);
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a = p->len+1+i+1;
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if(a > p->alen){
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a += PATHSLOP;
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t = smalloc(a);
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memmove(t, p->s, p->len+1);
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free(p->s);
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p->s = t;
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p->alen = a;
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}
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/* don't insert extra slash if one is present */
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if(p->len>0 && p->s[p->len-1]!='/' && s[0]!='/')
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p->s[p->len++] = '/';
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memmove(p->s+p->len, s, i+1);
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p->len += i;
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if(isdotdot(s)){
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fixdotdotname(p);
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if(p->mlen > 1 && (c = p->mtpt[--p->mlen]) != nil){
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p->mtpt[p->mlen] = nil;
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cclose(c);
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}
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}else{
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if(p->mlen >= p->malen){
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p->malen = p->mlen+1+PATHMSLOP;
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tt = smalloc(p->malen*sizeof tt[0]);
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memmove(tt, p->mtpt, p->mlen*sizeof tt[0]);
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free(p->mtpt);
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p->mtpt = tt;
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}
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p->mtpt[p->mlen++] = from;
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if(from != nil)
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incref(from);
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}
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return p;
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}
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void
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chanfree(Chan *c)
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{
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c->flag = CFREE;
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if(c->dirrock != nil){
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free(c->dirrock);
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c->dirrock = nil;
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c->nrock = 0;
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c->mrock = 0;
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}
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if(c->umh != nil){
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putmhead(c->umh);
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c->umh = nil;
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}
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if(c->umc != nil){
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cclose(c->umc);
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c->umc = nil;
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}
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if(c->mux != nil){
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muxclose(c->mux);
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c->mux = nil;
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}
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if(c->mchan != nil){
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cclose(c->mchan);
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c->mchan = nil;
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}
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pathclose(c->path);
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c->path = nil;
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lock(&chanalloc);
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c->next = chanalloc.free;
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chanalloc.free = c;
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unlock(&chanalloc);
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}
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/*
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* Queue a chan to be closed by one of the clunk procs.
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*/
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struct {
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Chan *head;
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Chan *tail;
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ulong nqueued;
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ulong nclosed;
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Lock l;
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QLock q;
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Rendez r;
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} clunkq;
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static int
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clunkwork(void*)
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{
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return clunkq.head != nil;
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}
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static void
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closechanq(Chan *c)
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{
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lock(&clunkq.l);
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clunkq.nqueued++;
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c->next = nil;
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if(clunkq.head != nil)
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clunkq.tail->next = c;
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else
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clunkq.head = c;
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clunkq.tail = c;
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unlock(&clunkq.l);
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wakeup(&clunkq.r);
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}
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static Chan*
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closechandeq(void)
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{
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Chan *c;
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lock(&clunkq.l);
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c = clunkq.head;
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if(c != nil) {
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clunkq.head = c->next;
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clunkq.nclosed++;
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}
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unlock(&clunkq.l);
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return c;
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}
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static void
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closeproc(void *)
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{
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Chan *c;
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for(;;){
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c = closechandeq();
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if(c == nil) {
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qlock(&clunkq.q);
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if(!waserror()) {
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tsleep(&clunkq.r, clunkwork, nil, 500);
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poperror();
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}
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c = closechandeq();
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if(c == nil) {
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if(clunkq.q.head != nil) {
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qunlock(&clunkq.q);
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pexit("no work", 1);
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}
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qunlock(&clunkq.q);
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continue;
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}
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if(clunkq.q.head == nil) {
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if(!waserror()) {
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kproc("closeproc", closeproc, nil);
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poperror();
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}
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}
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qunlock(&clunkq.q);
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}
|
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if(!waserror()){
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devtab[c->type]->close(c);
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poperror();
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}
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chanfree(c);
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}
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}
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void
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cclose(Chan *c)
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{
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if(c == nil || c->ref < 1 || c->flag&CFREE)
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panic("cclose %#p", getcallerpc(&c));
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if(decref(c))
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return;
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|
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if(devtab[c->type]->dc == L'M')
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if((c->flag&COPEN) == 0 || (c->flag&(CRCLOSE|CCACHE)) == CCACHE)
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if((c->qid.type&(QTEXCL|QTMOUNT|QTAUTH)) == 0)
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if((clunkq.nqueued - clunkq.nclosed) < 64){
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closechanq(c);
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return;
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}
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|
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if(!waserror()){
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devtab[c->type]->close(c);
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poperror();
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}
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chanfree(c);
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}
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|
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void
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ccloseq(Chan *c)
|
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{
|
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if(c == nil || c->ref < 1 || c->flag&CFREE)
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panic("ccloseq %#p", getcallerpc(&c));
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|
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if(decref(c) == 0)
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closechanq(c);
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}
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|
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/*
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|
* Make sure we have the only copy of c. (Copy on write.)
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*/
|
|
Chan*
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cunique(Chan *c)
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|
{
|
|
Chan *nc;
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|
|
if(c->ref != 1){
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nc = cclone(c);
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cclose(c);
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c = nc;
|
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}
|
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|
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if(c->umh != nil){ //BUG
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print("cunique umh != nil from %#p\n", getcallerpc(&c));
|
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putmhead(c->umh);
|
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c->umh = nil;
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}
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return c;
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}
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|
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int
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eqqid(Qid a, Qid b)
|
|
{
|
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return a.path==b.path && a.vers==b.vers;
|
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}
|
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|
|
int
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eqchan(Chan *a, Chan *b, int skipvers)
|
|
{
|
|
if(a->qid.path != b->qid.path)
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return 0;
|
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if(!skipvers && a->qid.vers!=b->qid.vers)
|
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return 0;
|
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if(a->type != b->type)
|
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return 0;
|
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if(a->dev != b->dev)
|
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return 0;
|
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return 1;
|
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}
|
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|
|
int
|
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eqchantdqid(Chan *a, int type, int dev, Qid qid, int skipvers)
|
|
{
|
|
if(a->qid.path != qid.path)
|
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return 0;
|
|
if(!skipvers && a->qid.vers!=qid.vers)
|
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return 0;
|
|
if(a->type != type)
|
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return 0;
|
|
if(a->dev != dev)
|
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return 0;
|
|
return 1;
|
|
}
|
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|
|
Mhead*
|
|
newmhead(Chan *from)
|
|
{
|
|
Mhead *mh;
|
|
|
|
mh = smalloc(sizeof(Mhead));
|
|
mh->ref = 1;
|
|
mh->from = from;
|
|
incref(from);
|
|
setmalloctag(mh, getcallerpc(&from));
|
|
return mh;
|
|
}
|
|
|
|
/*
|
|
* This is necessary because there are many
|
|
* pointers to the top of a given mount list:
|
|
*
|
|
* - the mhead in the namespace hash table
|
|
* - the mhead in chans returned from findmount:
|
|
* used in namec and then by unionread.
|
|
* - the mhead in chans returned from createdir:
|
|
* used in the open/create race protect, which is gone.
|
|
*
|
|
* The RWlock in the Mhead protects the mount list it contains.
|
|
* The mount list is deleted in cunmount() and closepgrp().
|
|
* The RWlock ensures that nothing is using the mount list at that time.
|
|
*
|
|
* It is okay to replace c->mh with whatever you want as
|
|
* long as you are sure you have a unique reference to it.
|
|
*
|
|
* This comment might belong somewhere else.
|
|
*/
|
|
void
|
|
putmhead(Mhead *m)
|
|
{
|
|
if(m == nil)
|
|
return;
|
|
if(decref(m))
|
|
return;
|
|
assert(m->mount == nil);
|
|
cclose(m->from);
|
|
free(m);
|
|
}
|
|
|
|
int
|
|
cmount(Chan *new, Chan *old, int flag, char *spec)
|
|
{
|
|
int order;
|
|
Mhead *m, **l, *mh;
|
|
Mount *nm, *f, *um;
|
|
Pgrp *pg;
|
|
|
|
if(old->umh != nil)
|
|
print("cmount: unexpected umh, caller %#p\n", getcallerpc(&new));
|
|
|
|
if(QTDIR & (old->qid.type^new->qid.type))
|
|
error(Emount);
|
|
|
|
order = flag&MORDER;
|
|
|
|
if((old->qid.type&QTDIR) == 0 && order != MREPL)
|
|
error(Emount);
|
|
|
|
nm = newmount(new, flag, spec);
|
|
mh = new->umh;
|
|
if(mh != nil) {
|
|
rlock(&mh->lock);
|
|
if(waserror()) {
|
|
runlock(&mh->lock);
|
|
mountfree(nm);
|
|
nexterror();
|
|
}
|
|
um = mh->mount;
|
|
if(um != nil){
|
|
/*
|
|
* Not allowed to bind when the old directory is itself a union.
|
|
* (Maybe it should be allowed, but I don't see what the semantics
|
|
* would be.)
|
|
*
|
|
* We need to check mh->mount->next to tell unions apart from
|
|
* simple mount points, so that things like
|
|
* mount -c fd /root
|
|
* bind -c /root /
|
|
* work.
|
|
*
|
|
* The check of mount->mflag allows things like
|
|
* mount fd /root
|
|
* bind -c /root /
|
|
*
|
|
* This is far more complicated than it should be, but I don't
|
|
* see an easier way at the moment.
|
|
*/
|
|
if((flag&MCREATE) != 0 && (um->next != nil || (um->mflag&MCREATE) == 0))
|
|
error(Emount);
|
|
|
|
/*
|
|
* copy a union when binding it onto a directory
|
|
*/
|
|
f = nm;
|
|
for(um = um->next; um != nil; um = um->next){
|
|
f->next = newmount(um->to, order==MREPL? MAFTER: order, um->spec);
|
|
f = f->next;
|
|
}
|
|
}
|
|
runlock(&mh->lock);
|
|
poperror();
|
|
}
|
|
|
|
pg = up->pgrp;
|
|
wlock(&pg->ns);
|
|
l = &MOUNTH(pg, old->qid);
|
|
for(m = *l; m != nil; m = m->hash){
|
|
if(eqchan(m->from, old, 1))
|
|
break;
|
|
l = &m->hash;
|
|
}
|
|
if(m == nil){
|
|
/*
|
|
* nothing mounted here yet. create a mount
|
|
* head and add to the hash table.
|
|
*/
|
|
m = newmhead(old);
|
|
/*
|
|
* if this is a union mount, add the old
|
|
* node to the mount chain.
|
|
*/
|
|
if(order != MREPL)
|
|
m->mount = newmount(old, 0, nil);
|
|
*l = m;
|
|
}
|
|
wlock(&m->lock);
|
|
um = m->mount;
|
|
if(um != nil && order == MAFTER){
|
|
for(f = um; f->next != nil; f = f->next)
|
|
;
|
|
f->next = nm;
|
|
um = nil;
|
|
} else {
|
|
if(order != MREPL){
|
|
for(f = nm; f->next != nil; f = f->next)
|
|
;
|
|
f->next = um;
|
|
um = nil;
|
|
}
|
|
m->mount = nm;
|
|
}
|
|
order = nm->mountid;
|
|
wunlock(&m->lock);
|
|
wunlock(&pg->ns);
|
|
|
|
mountfree(um);
|
|
|
|
return order;
|
|
}
|
|
|
|
void
|
|
cunmount(Chan *mnt, Chan *mounted)
|
|
{
|
|
Pgrp *pg;
|
|
Mhead *m, **l;
|
|
Mount *f, **p;
|
|
|
|
if(mnt->umh != nil) /* should not happen */
|
|
print("cunmount newp extra umh %p has %p\n", mnt, mnt->umh);
|
|
|
|
/*
|
|
* It _can_ happen that mounted->umh is non-nil,
|
|
* because mounted is the result of namec(Aopen)
|
|
* (see sysfile.c:/^sysunmount).
|
|
* If we open a union directory, it will have a umh.
|
|
* Although surprising, this is okay, since the
|
|
* cclose will take care of freeing the umh.
|
|
*/
|
|
|
|
pg = up->pgrp;
|
|
wlock(&pg->ns);
|
|
|
|
l = &MOUNTH(pg, mnt->qid);
|
|
for(m = *l; m != nil; m = m->hash){
|
|
if(eqchan(m->from, mnt, 1))
|
|
break;
|
|
l = &m->hash;
|
|
}
|
|
|
|
if(m == nil){
|
|
wunlock(&pg->ns);
|
|
error(Eunmount);
|
|
}
|
|
|
|
wlock(&m->lock);
|
|
f = m->mount;
|
|
if(mounted == nil){
|
|
*l = m->hash;
|
|
m->mount = nil;
|
|
wunlock(&m->lock);
|
|
wunlock(&pg->ns);
|
|
mountfree(f);
|
|
putmhead(m);
|
|
return;
|
|
}
|
|
for(p = &m->mount; f != nil; f = f->next){
|
|
if(eqchan(f->to, mounted, 1) ||
|
|
(f->to->mchan != nil && eqchan(f->to->mchan, mounted, 1))){
|
|
*p = f->next;
|
|
f->next = nil;
|
|
if(m->mount == nil){
|
|
*l = m->hash;
|
|
wunlock(&m->lock);
|
|
wunlock(&pg->ns);
|
|
mountfree(f);
|
|
putmhead(m);
|
|
return;
|
|
}
|
|
wunlock(&m->lock);
|
|
wunlock(&pg->ns);
|
|
mountfree(f);
|
|
return;
|
|
}
|
|
p = &f->next;
|
|
}
|
|
wunlock(&m->lock);
|
|
wunlock(&pg->ns);
|
|
error(Eunion);
|
|
}
|
|
|
|
Chan*
|
|
cclone(Chan *c)
|
|
{
|
|
Chan *nc;
|
|
Walkqid *wq;
|
|
|
|
if(c == nil || c->ref < 1 || c->flag&CFREE)
|
|
panic("cclone: %#p", getcallerpc(&c));
|
|
wq = devtab[c->type]->walk(c, nil, nil, 0);
|
|
if(wq == nil)
|
|
error("clone failed");
|
|
nc = wq->clone;
|
|
free(wq);
|
|
if((nc->path = c->path) != nil)
|
|
incref(c->path);
|
|
return nc;
|
|
}
|
|
|
|
/* also used by sysfile.c:/^mountfix */
|
|
int
|
|
findmount(Chan **cp, Mhead **mp, int type, int dev, Qid qid)
|
|
{
|
|
Chan *to;
|
|
Pgrp *pg;
|
|
Mhead *m;
|
|
|
|
pg = up->pgrp;
|
|
rlock(&pg->ns);
|
|
for(m = MOUNTH(pg, qid); m != nil; m = m->hash){
|
|
if(eqchantdqid(m->from, type, dev, qid, 1)){
|
|
if(mp != nil)
|
|
incref(m);
|
|
rlock(&m->lock);
|
|
to = m->mount->to;
|
|
incref(to);
|
|
runlock(&m->lock);
|
|
runlock(&pg->ns);
|
|
if(mp != nil){
|
|
putmhead(*mp);
|
|
*mp = m;
|
|
}
|
|
if(*cp != nil)
|
|
cclose(*cp);
|
|
*cp = to;
|
|
return 1;
|
|
}
|
|
}
|
|
runlock(&pg->ns);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Calls findmount but also updates path.
|
|
*/
|
|
static int
|
|
domount(Chan **cp, Mhead **mp, Path **path)
|
|
{
|
|
Chan **lc, *from;
|
|
Path *p;
|
|
|
|
if(findmount(cp, mp, (*cp)->type, (*cp)->dev, (*cp)->qid) == 0)
|
|
return 0;
|
|
|
|
if(path != nil){
|
|
p = *path;
|
|
p = uniquepath(p);
|
|
if(p->mlen <= 0)
|
|
print("domount: path %s has mlen==%d\n", p->s, p->mlen);
|
|
else{
|
|
from = (*mp)->from;
|
|
incref(from);
|
|
lc = &p->mtpt[p->mlen-1];
|
|
if(*lc != nil)
|
|
cclose(*lc);
|
|
*lc = from;
|
|
}
|
|
*path = p;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* If c is the right-hand-side of a mount point, returns the left hand side.
|
|
* Changes name to reflect the fact that we've uncrossed the mountpoint,
|
|
* so name had better be ours to change!
|
|
*/
|
|
static Chan*
|
|
undomount(Chan *c, Path *path)
|
|
{
|
|
Chan *nc;
|
|
|
|
if(path->ref != 1 || path->mlen == 0)
|
|
print("undomount: path %s ref %ld mlen %d caller %#p\n",
|
|
path->s, path->ref, path->mlen, getcallerpc(&c));
|
|
|
|
if(path->mlen > 0 && (nc = path->mtpt[path->mlen-1]) != nil){
|
|
cclose(c);
|
|
path->mtpt[path->mlen-1] = nil;
|
|
c = nc;
|
|
}
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* Call dev walk but catch errors.
|
|
*/
|
|
static Walkqid*
|
|
ewalk(Chan *c, Chan *nc, char **name, int nname)
|
|
{
|
|
Walkqid *wq;
|
|
|
|
if(waserror())
|
|
return nil;
|
|
wq = devtab[c->type]->walk(c, nc, name, nname);
|
|
poperror();
|
|
return wq;
|
|
}
|
|
|
|
/*
|
|
* Either walks all the way or not at all. No partial results in *cp.
|
|
* *nerror is the number of names to display in an error message.
|
|
*/
|
|
static char Edoesnotexist[] = "does not exist";
|
|
int
|
|
walk(Chan **cp, char **names, int nnames, int nomount, int *nerror)
|
|
{
|
|
int dev, didmount, dotdot, i, n, nhave, ntry, type;
|
|
Chan *c, *nc, *mtpt;
|
|
Path *path;
|
|
Mhead *mh, *nmh;
|
|
Mount *f;
|
|
Walkqid *wq;
|
|
|
|
c = *cp;
|
|
incref(c);
|
|
path = c->path;
|
|
incref(path);
|
|
mh = nil;
|
|
|
|
/*
|
|
* While we haven't gotten all the way down the path:
|
|
* 1. step through a mount point, if any
|
|
* 2. send a walk request for initial dotdot or initial prefix without dotdot
|
|
* 3. move to the first mountpoint along the way.
|
|
* 4. repeat.
|
|
*
|
|
* Each time through the loop:
|
|
*
|
|
* If didmount==0, c is on the undomount side of the mount point.
|
|
* If didmount==1, c is on the domount side of the mount point.
|
|
* Either way, c's full path is path.
|
|
*/
|
|
didmount = 0;
|
|
for(nhave=0; nhave<nnames; nhave+=n){
|
|
if((c->qid.type&QTDIR) == 0){
|
|
if(nerror)
|
|
*nerror = nhave;
|
|
pathclose(path);
|
|
cclose(c);
|
|
kstrcpy(up->errstr, Enotdir, ERRMAX);
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
ntry = nnames - nhave;
|
|
if(ntry > MAXWELEM)
|
|
ntry = MAXWELEM;
|
|
dotdot = 0;
|
|
for(i=0; i<ntry; i++){
|
|
if(isdotdot(names[nhave+i])){
|
|
if(i==0){
|
|
dotdot = 1;
|
|
ntry = 1;
|
|
}else
|
|
ntry = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if(!dotdot && !nomount && !didmount)
|
|
domount(&c, &mh, &path);
|
|
|
|
type = c->type;
|
|
dev = c->dev;
|
|
|
|
if((wq = ewalk(c, nil, names+nhave, ntry)) == nil){
|
|
/* try a union mount, if any */
|
|
if(mh != nil && !nomount){
|
|
/*
|
|
* mh->mount->to == c, so start at mh->mount->next
|
|
*/
|
|
rlock(&mh->lock);
|
|
if((f = mh->mount) != nil)
|
|
f = f->next;
|
|
for(; f != nil; f = f->next)
|
|
if((wq = ewalk(f->to, nil, names+nhave, ntry)) != nil){
|
|
type = f->to->type;
|
|
dev = f->to->dev;
|
|
break;
|
|
}
|
|
runlock(&mh->lock);
|
|
}
|
|
if(wq == nil){
|
|
cclose(c);
|
|
pathclose(path);
|
|
if(nerror)
|
|
*nerror = nhave+1;
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
didmount = 0;
|
|
if(dotdot){
|
|
assert(wq->nqid == 1);
|
|
assert(wq->clone != nil);
|
|
|
|
path = addelem(path, "..", nil);
|
|
nc = undomount(wq->clone, path);
|
|
nmh = nil;
|
|
n = 1;
|
|
}else{
|
|
nc = nil;
|
|
nmh = nil;
|
|
if(!nomount){
|
|
for(i=0; i<wq->nqid && i<ntry-1; i++){
|
|
if(findmount(&nc, &nmh, type, dev, wq->qid[i])){
|
|
didmount = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if(nc == nil){ /* no mount points along path */
|
|
if(wq->clone == nil){
|
|
cclose(c);
|
|
pathclose(path);
|
|
if(wq->nqid == 0 || (wq->qid[wq->nqid-1].type&QTDIR) != 0){
|
|
if(nerror)
|
|
*nerror = nhave+wq->nqid+1;
|
|
kstrcpy(up->errstr, Edoesnotexist, ERRMAX);
|
|
}else{
|
|
if(nerror)
|
|
*nerror = nhave+wq->nqid;
|
|
kstrcpy(up->errstr, Enotdir, ERRMAX);
|
|
}
|
|
free(wq);
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
n = wq->nqid;
|
|
nc = wq->clone;
|
|
}else{ /* stopped early, at a mount point */
|
|
assert(didmount);
|
|
if(wq->clone != nil){
|
|
cclose(wq->clone);
|
|
wq->clone = nil;
|
|
}
|
|
n = i+1;
|
|
}
|
|
for(i=0; i<n; i++){
|
|
mtpt = nil;
|
|
if(i==n-1 && nmh!=nil)
|
|
mtpt = nmh->from;
|
|
path = addelem(path, names[nhave+i], mtpt);
|
|
}
|
|
}
|
|
cclose(c);
|
|
c = nc;
|
|
putmhead(mh);
|
|
mh = nmh;
|
|
free(wq);
|
|
}
|
|
putmhead(mh);
|
|
c = cunique(c);
|
|
|
|
pathclose(c->path);
|
|
c->path = path;
|
|
|
|
cclose(*cp);
|
|
*cp = c;
|
|
if(nerror)
|
|
*nerror = nhave;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* c is a mounted non-creatable directory. find a creatable one.
|
|
*/
|
|
Chan*
|
|
createdir(Chan *c, Mhead *m)
|
|
{
|
|
Chan *nc;
|
|
Mount *f;
|
|
|
|
rlock(&m->lock);
|
|
if(waserror()){
|
|
runlock(&m->lock);
|
|
nexterror();
|
|
}
|
|
for(f = m->mount; f != nil; f = f->next){
|
|
if((f->mflag&MCREATE) != 0){
|
|
nc = cclone(f->to);
|
|
runlock(&m->lock);
|
|
poperror();
|
|
cclose(c);
|
|
return nc;
|
|
}
|
|
}
|
|
error(Enocreate);
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
saveregisters(void)
|
|
{
|
|
}
|
|
|
|
static void
|
|
growparse(Elemlist *e)
|
|
{
|
|
char **new;
|
|
int *inew;
|
|
enum { Delta = 8 };
|
|
|
|
if((e->nelems % Delta) == 0){
|
|
new = smalloc((e->nelems+Delta) * sizeof(char*));
|
|
memmove(new, e->elems, e->nelems*sizeof(char*));
|
|
free(e->elems);
|
|
e->elems = new;
|
|
inew = smalloc((e->nelems+Delta+1) * sizeof(int));
|
|
memmove(inew, e->off, (e->nelems+1)*sizeof(int));
|
|
free(e->off);
|
|
e->off = inew;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The name is known to be valid.
|
|
* Copy the name so slashes can be overwritten.
|
|
* An empty string will set nelem=0.
|
|
* A path ending in / or /. or /.//./ etc. will have
|
|
* e.mustbedir = 1, so that we correctly
|
|
* reject, e.g., "/adm/users/." when /adm/users is a file
|
|
* rather than a directory.
|
|
*/
|
|
static void
|
|
parsename(char *aname, Elemlist *e)
|
|
{
|
|
char *name, *slash;
|
|
|
|
kstrdup(&e->name, aname);
|
|
name = e->name;
|
|
e->nelems = 0;
|
|
e->elems = nil;
|
|
e->off = smalloc(sizeof(int));
|
|
e->off[0] = skipslash(name) - name;
|
|
for(;;){
|
|
name = skipslash(name);
|
|
if(*name == '\0'){
|
|
e->off[e->nelems] = name+strlen(name) - e->name;
|
|
e->mustbedir = 1;
|
|
break;
|
|
}
|
|
growparse(e);
|
|
e->elems[e->nelems++] = name;
|
|
slash = utfrune(name, '/');
|
|
if(slash == nil){
|
|
e->off[e->nelems] = name+strlen(name) - e->name;
|
|
e->mustbedir = 0;
|
|
break;
|
|
}
|
|
e->off[e->nelems] = slash - e->name;
|
|
*slash++ = '\0';
|
|
name = slash;
|
|
}
|
|
}
|
|
|
|
static void
|
|
namelenerror(char *aname, int len, char *err)
|
|
{
|
|
char *ename, *name, *next;
|
|
int i, errlen;
|
|
|
|
/*
|
|
* If the name is short enough, just use the whole thing.
|
|
*/
|
|
errlen = strlen(err);
|
|
if(len < ERRMAX/3 || len+errlen < 2*ERRMAX/3)
|
|
snprint(up->genbuf, sizeof up->genbuf, "%.*s",
|
|
utfnlen(aname, len), aname);
|
|
else{
|
|
/*
|
|
* Print a suffix of the name, but try to get a little info.
|
|
*/
|
|
ename = aname+len;
|
|
next = ename;
|
|
do{
|
|
name = next;
|
|
if(next == aname)
|
|
break;
|
|
while(next > aname)
|
|
if(*--next == '/')
|
|
break;
|
|
len = ename-next;
|
|
}while(len < ERRMAX/3 || len + errlen < 2*ERRMAX/3);
|
|
|
|
/*
|
|
* If the name is ridiculously long, chop it.
|
|
*/
|
|
if(name == ename){
|
|
name = ename-ERRMAX/4;
|
|
if(name <= aname)
|
|
panic("bad math in namelenerror");
|
|
/* walk out of current UTF sequence */
|
|
for(i=0; (*name&0xC0)==0x80 && i<UTFmax; i++)
|
|
name++;
|
|
}
|
|
snprint(up->genbuf, sizeof up->genbuf, "...%.*s",
|
|
utfnlen(name, ename-name), name);
|
|
}
|
|
snprint(up->errstr, ERRMAX, "%#q %s", up->genbuf, err);
|
|
nexterror();
|
|
}
|
|
|
|
void
|
|
nameerror(char *name, char *err)
|
|
{
|
|
namelenerror(name, strlen(name), err);
|
|
}
|
|
|
|
/*
|
|
* Turn a name into a channel.
|
|
* &name[0] is known to be a valid address. It may be a kernel address.
|
|
*
|
|
* Opening with amode Aopen, Acreate, Aremove, or Aaccess guarantees
|
|
* that the result will be the only reference to that particular fid.
|
|
* This is necessary since we might pass the result to
|
|
* devtab[]->remove().
|
|
*
|
|
* Opening Atodir or Amount does not guarantee this.
|
|
*
|
|
* Under certain circumstances, opening Aaccess will cause
|
|
* an unnecessary clone in order to get a cunique Chan so it
|
|
* can attach the correct name. Sysstat and sys_stat need the
|
|
* correct name so they can rewrite the stat info.
|
|
*/
|
|
Chan*
|
|
namec(char *aname, int amode, int omode, ulong perm)
|
|
{
|
|
int len, n, t, nomount, devunmount;
|
|
Chan *c;
|
|
Chan *volatile cnew;
|
|
Path *volatile path;
|
|
Elemlist e;
|
|
Rune r;
|
|
Mhead *m;
|
|
char *err;
|
|
char *name;
|
|
|
|
if(aname[0] == '\0')
|
|
error("empty file name");
|
|
aname = validnamedup(aname, 1);
|
|
if(waserror()){
|
|
free(aname);
|
|
nexterror();
|
|
}
|
|
name = aname;
|
|
|
|
/*
|
|
* When unmounting, the name parameter must be accessed
|
|
* using Aopen in order to get the real chan from
|
|
* something like /srv/cs or /fd/0. However when sandboxing,
|
|
* unmounting a sharp from a union is a valid operation even
|
|
* if the device is blocked.
|
|
*/
|
|
devunmount = 0;
|
|
if(amode == Aunmount){
|
|
/*
|
|
* Doing any walks down the device could leak information
|
|
* about the existence of files.
|
|
*/
|
|
if(name[0] == '#' && utflen(name) == 2)
|
|
devunmount = 1;
|
|
amode = Aopen;
|
|
}
|
|
|
|
/*
|
|
* Find the starting off point (the current slash, the root of
|
|
* a device tree, or the current dot) as well as the name to
|
|
* evaluate starting there.
|
|
*/
|
|
nomount = 0;
|
|
switch(name[0]){
|
|
case '/':
|
|
c = up->slash;
|
|
incref(c);
|
|
break;
|
|
|
|
case '#':
|
|
nomount = 1;
|
|
up->genbuf[0] = '\0';
|
|
n = 0;
|
|
while(*name != '\0' && (*name != '/' || n < 2)){
|
|
if(n >= sizeof(up->genbuf)-1)
|
|
error(Efilename);
|
|
up->genbuf[n++] = *name++;
|
|
}
|
|
up->genbuf[n] = '\0';
|
|
n = chartorune(&r, up->genbuf+1)+1;
|
|
t = devno(r, 1);
|
|
if(t == -1)
|
|
error(Ebadsharp);
|
|
if(!devunmount && !devallowed(up->pgrp, r))
|
|
error(Enoattach);
|
|
|
|
c = devtab[t]->attach(up->genbuf+n);
|
|
break;
|
|
|
|
default:
|
|
c = up->dot;
|
|
incref(c);
|
|
break;
|
|
}
|
|
|
|
e.aname = aname;
|
|
e.prefix = name - aname;
|
|
e.name = nil;
|
|
e.elems = nil;
|
|
e.off = nil;
|
|
e.nelems = 0;
|
|
e.nerror = 0;
|
|
if(waserror()){
|
|
cclose(c);
|
|
free(e.name);
|
|
free(e.elems);
|
|
/*
|
|
* Prepare nice error, showing first e.nerror elements of name.
|
|
*/
|
|
if(e.nerror == 0)
|
|
nexterror();
|
|
if(e.off[e.nerror]==0)
|
|
print("nerror=%d but off=%d\n",
|
|
e.nerror, e.off[e.nerror]);
|
|
len = e.prefix+e.off[e.nerror];
|
|
free(e.off);
|
|
err = up->errstr;
|
|
up->errstr = up->syserrstr;
|
|
up->syserrstr = err;
|
|
namelenerror(aname, len, err);
|
|
}
|
|
|
|
/*
|
|
* Build a list of elements in the name.
|
|
*/
|
|
parsename(name, &e);
|
|
|
|
/*
|
|
* On create, ....
|
|
*/
|
|
if(amode == Acreate){
|
|
/* perm must have DMDIR if last element is / or /. */
|
|
if(e.mustbedir && !(perm&DMDIR)){
|
|
e.nerror = e.nelems;
|
|
error("create without DMDIR");
|
|
}
|
|
|
|
/* don't try to walk the last path element just yet. */
|
|
if(e.nelems == 0)
|
|
error(Eexist);
|
|
e.nelems--;
|
|
}
|
|
|
|
if(walk(&c, e.elems, e.nelems, nomount, &e.nerror) < 0){
|
|
if(e.nerror < 0 || e.nerror > e.nelems){
|
|
print("namec %s walk error nerror=%d\n", aname, e.nerror);
|
|
e.nerror = 0;
|
|
}
|
|
nexterror();
|
|
}
|
|
|
|
if(e.mustbedir && (c->qid.type&QTDIR) == 0)
|
|
error("not a directory");
|
|
|
|
if(amode == Aopen && (omode&3) == OEXEC && (c->qid.type&QTDIR) != 0)
|
|
error("cannot exec directory");
|
|
|
|
switch(amode){
|
|
case Abind:
|
|
/* no need to maintain path - cannot dotdot an Abind */
|
|
m = nil;
|
|
if(!nomount)
|
|
domount(&c, &m, nil);
|
|
if(waserror()){
|
|
putmhead(m);
|
|
nexterror();
|
|
}
|
|
c = cunique(c);
|
|
c->umh = m;
|
|
poperror();
|
|
break;
|
|
|
|
case Aaccess:
|
|
case Aremove:
|
|
case Aopen:
|
|
Open:
|
|
/* save&update the name; domount might change c */
|
|
path = c->path;
|
|
incref(path);
|
|
if(waserror()){
|
|
pathclose(path);
|
|
nexterror();
|
|
}
|
|
m = nil;
|
|
if(!nomount)
|
|
domount(&c, &m, &path);
|
|
if(waserror()){
|
|
putmhead(m);
|
|
nexterror();
|
|
}
|
|
/* our own copy to open or remove */
|
|
c = cunique(c);
|
|
poperror();
|
|
|
|
/* now it's our copy anyway, we can put the name back */
|
|
pathclose(c->path);
|
|
c->path = path;
|
|
poperror();
|
|
|
|
/* record whether c is on a mount point */
|
|
c->ismtpt = m!=nil;
|
|
|
|
switch(amode){
|
|
case Aaccess:
|
|
case Aremove:
|
|
putmhead(m);
|
|
break;
|
|
|
|
case Aopen:
|
|
case Acreate:
|
|
/* only save the mount head if it's a multiple element union */
|
|
if(m != nil) {
|
|
rlock(&m->lock);
|
|
if(m->mount != nil && m->mount->next != nil) {
|
|
c->umh = m;
|
|
runlock(&m->lock);
|
|
} else {
|
|
runlock(&m->lock);
|
|
putmhead(m);
|
|
}
|
|
}
|
|
|
|
/* save registers else error() in open has wrong value of c saved */
|
|
saveregisters();
|
|
|
|
c = devtab[c->type]->open(c, omode&~OCEXEC);
|
|
if(omode & ORCLOSE)
|
|
c->flag |= CRCLOSE;
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case Atodir:
|
|
/*
|
|
* Directories (e.g. for cd) are left before the mount point,
|
|
* so one may mount on / or . and see the effect.
|
|
*/
|
|
if((c->qid.type&QTDIR) == 0)
|
|
error(Enotdir);
|
|
break;
|
|
|
|
case Amount:
|
|
/*
|
|
* When mounting on an already mounted upon directory,
|
|
* one wants subsequent mounts to be attached to the
|
|
* original directory, not the replacement. Don't domount.
|
|
*/
|
|
break;
|
|
|
|
case Acreate:
|
|
/*
|
|
* We've already walked all but the last element.
|
|
* If the last exists, try to open it OTRUNC.
|
|
* If omode&OEXCL is set, just give up.
|
|
*/
|
|
e.nelems++;
|
|
e.nerror++;
|
|
if(walk(&c, e.elems+e.nelems-1, 1, nomount, nil) == 0){
|
|
if(omode&OEXCL)
|
|
error(Eexist);
|
|
omode |= OTRUNC;
|
|
goto Open;
|
|
}
|
|
|
|
/*
|
|
* The semantics of the create(2) system call are that if the
|
|
* file exists and can be written, it is to be opened with truncation.
|
|
* On the other hand, the create(5) message fails if the file exists.
|
|
* If we get two create(2) calls happening simultaneously,
|
|
* they might both get here and send create(5) messages, but only
|
|
* one of the messages will succeed. To provide the expected create(2)
|
|
* semantics, the call with the failed message needs to try the above
|
|
* walk again, opening for truncation. This correctly solves the
|
|
* create/create race, in the sense that any observable outcome can
|
|
* be explained as one happening before the other.
|
|
* The create/create race is quite common. For example, it happens
|
|
* when two rc subshells simultaneously update the same
|
|
* environment variable.
|
|
*
|
|
* The implementation still admits a create/create/remove race:
|
|
* (A) walk to file, fails
|
|
* (B) walk to file, fails
|
|
* (A) create file, succeeds, returns
|
|
* (B) create file, fails
|
|
* (A) remove file, succeeds, returns
|
|
* (B) walk to file, return failure.
|
|
*
|
|
* This is hardly as common as the create/create race, and is really
|
|
* not too much worse than what might happen if (B) got a hold of a
|
|
* file descriptor and then the file was removed -- either way (B) can't do
|
|
* anything with the result of the create call. So we don't care about this race.
|
|
*
|
|
* Applications that care about more fine-grained decision of the races
|
|
* can use the OEXCL flag to get at the underlying create(5) semantics;
|
|
* by default we provide the common case.
|
|
*
|
|
* We need to stay behind the mount point in case we
|
|
* need to do the first walk again (should the create fail).
|
|
*
|
|
* We also need to cross the mount point and find the directory
|
|
* in the union in which we should be creating.
|
|
*
|
|
* The channel staying behind is c, the one moving forward is cnew.
|
|
*/
|
|
m = nil;
|
|
cnew = nil; /* is this assignment necessary? */
|
|
if(!waserror()){ /* try create */
|
|
if(!nomount && findmount(&cnew, &m, c->type, c->dev, c->qid))
|
|
cnew = createdir(cnew, m);
|
|
else{
|
|
cnew = c;
|
|
incref(cnew);
|
|
}
|
|
|
|
/*
|
|
* We need our own copy of the Chan because we're
|
|
* about to send a create, which will move it. Once we have
|
|
* our own copy, we can fix the name, which might be wrong
|
|
* if findmount gave us a new Chan.
|
|
*/
|
|
cnew = cunique(cnew);
|
|
pathclose(cnew->path);
|
|
cnew->path = c->path;
|
|
incref(cnew->path);
|
|
|
|
cnew = devtab[cnew->type]->create(cnew, e.elems[e.nelems-1], omode&~(OEXCL|OCEXEC), perm);
|
|
if(omode & ORCLOSE)
|
|
cnew->flag |= CRCLOSE;
|
|
poperror();
|
|
putmhead(m);
|
|
cclose(c);
|
|
c = cnew;
|
|
c->path = addelem(c->path, e.elems[e.nelems-1], nil);
|
|
break;
|
|
}
|
|
|
|
/* create failed */
|
|
cclose(cnew);
|
|
putmhead(m);
|
|
if(omode & OEXCL)
|
|
nexterror();
|
|
/* save error */
|
|
err = up->errstr;
|
|
up->errstr = up->syserrstr;
|
|
up->syserrstr = err;
|
|
/* note: we depend that walk does not error */
|
|
if(walk(&c, e.elems+e.nelems-1, 1, nomount, nil) < 0)
|
|
error(err); /* report true error */
|
|
/* restore error */
|
|
err = up->syserrstr;
|
|
up->syserrstr = up->errstr;
|
|
up->errstr = err;
|
|
omode |= OTRUNC;
|
|
goto Open;
|
|
|
|
default:
|
|
panic("unknown namec access %d", amode);
|
|
}
|
|
|
|
/* place final element in genbuf for e.g. exec */
|
|
if(e.nelems > 0)
|
|
kstrcpy(up->genbuf, e.elems[e.nelems-1], sizeof up->genbuf);
|
|
else
|
|
kstrcpy(up->genbuf, ".", sizeof up->genbuf);
|
|
free(e.name);
|
|
free(e.elems);
|
|
free(e.off);
|
|
poperror(); /* e c */
|
|
free(aname);
|
|
poperror(); /* aname */
|
|
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* name is valid. skip leading / and ./ as much as possible
|
|
*/
|
|
char*
|
|
skipslash(char *name)
|
|
{
|
|
while(name[0]=='/' || (name[0]=='.' && (name[1]==0 || name[1]=='/')))
|
|
name++;
|
|
return name;
|
|
}
|
|
|
|
char isfrog[256]={
|
|
/*NUL*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*BKS*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*DLE*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*CAN*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
['/'] 1,
|
|
[0x7f] 1,
|
|
};
|
|
|
|
/*
|
|
* Check that the name
|
|
* a) is in valid memory.
|
|
* b) is shorter than 2^16 bytes, so it can fit in a 9P string field.
|
|
* c) contains no frogs.
|
|
* The first byte is known to be addressible by the requester, so the
|
|
* routine works for kernel and user memory both.
|
|
* The parameter slashok flags whether a slash character is an error
|
|
* or a valid character.
|
|
*
|
|
* The parameter dup flags whether the string should be copied
|
|
* out of user space before being scanned the second time.
|
|
* (Otherwise a malicious thread could remove the NUL, causing us
|
|
* to access unchecked addresses.)
|
|
*/
|
|
static char*
|
|
validname0(char *aname, int slashok, int dup, uintptr pc)
|
|
{
|
|
char *ename, *name, *s;
|
|
int c, n;
|
|
Rune r;
|
|
|
|
name = aname;
|
|
if((uintptr)name < KZERO){
|
|
if(!dup)
|
|
print("warning: validname called from %#p with user pointer", pc);
|
|
ename = vmemchr(name, 0, (1<<16));
|
|
}else
|
|
ename = memchr(name, 0, (1<<16));
|
|
|
|
if(ename==nil || ename-name>=(1<<16))
|
|
error(Etoolong);
|
|
|
|
s = nil;
|
|
if(dup){
|
|
n = ename-name;
|
|
s = smalloc(n+1);
|
|
memmove(s, name, n);
|
|
s[n] = 0;
|
|
aname = s;
|
|
name = s;
|
|
setmalloctag(s, pc);
|
|
}
|
|
|
|
while(*name){
|
|
/* all characters above '~' are ok */
|
|
c = *(uchar*)name;
|
|
if(c >= Runeself)
|
|
name += chartorune(&r, name);
|
|
else{
|
|
if(isfrog[c])
|
|
if(!slashok || c!='/'){
|
|
snprint(up->genbuf, sizeof(up->genbuf), "%s: %q", Ebadchar, aname);
|
|
free(s);
|
|
error(up->genbuf);
|
|
}
|
|
name++;
|
|
}
|
|
}
|
|
return s;
|
|
}
|
|
|
|
void
|
|
validname(char *aname, int slashok)
|
|
{
|
|
validname0(aname, slashok, 0, getcallerpc(&aname));
|
|
}
|
|
|
|
char*
|
|
validnamedup(char *aname, int slashok)
|
|
{
|
|
return validname0(aname, slashok, 1, getcallerpc(&aname));
|
|
}
|
|
|
|
void
|
|
isdir(Chan *c)
|
|
{
|
|
if(c->qid.type & QTDIR)
|
|
return;
|
|
error(Enotdir);
|
|
}
|
|
|
|
|
|
enum
|
|
{
|
|
DIRSIZE = STATFIXLEN + 16 * 4 /* enough for encoded stat buf + some reasonable strings */
|
|
};
|
|
|
|
Dir*
|
|
dirchanstat(Chan *c)
|
|
{
|
|
Dir *d;
|
|
uchar *buf;
|
|
int n, nd, i;
|
|
|
|
nd = DIRSIZE;
|
|
for(i=0; i<2; i++){ /* should work by the second try */
|
|
d = smalloc(sizeof(Dir) + BIT16SZ + nd);
|
|
if(waserror()){
|
|
free(d);
|
|
nexterror();
|
|
}
|
|
buf = (uchar*)&d[1];
|
|
n = devtab[c->type]->stat(c, buf, BIT16SZ+nd);
|
|
if(n < BIT16SZ)
|
|
error(Eshortstat);
|
|
nd = GBIT16(buf); /* upper bound on size of Dir + strings */
|
|
if(nd <= n){
|
|
if(convM2D(buf, n, d, (char*)&d[1]) == 0)
|
|
error(Eshortstat);
|
|
poperror();
|
|
return d;
|
|
}
|
|
/* else sizeof(Dir)+BIT16SZ+nd is plenty */
|
|
free(d);
|
|
poperror();
|
|
}
|
|
error(Eshortstat);
|
|
return nil;
|
|
}
|