ref: c19685c19ee0eb9c9bcfe8d89ab1fea5231216ea
author: Sigrid Haflínudóttir <ftrvxmtrx@gmail.com>
date: Sun Dec 22 10:37:19 EST 2019
Squashed 'c9/' content from commit 24bfa2e git-subtree-dir: c9 git-subtree-split: 24bfa2e98819929991dffd38d74f40a833779180
--- /dev/null
+++ b/LICENSE
@@ -1,0 +1,1 @@
+Public domain.
--- /dev/null
+++ b/README.md
@@ -1,0 +1,8 @@
+# c9
+
+Low level 9p client and server.
+
+## Examples
+
+Until I have time to write a minimal example you could take a look at
+https://github.com/ftrvxmtrx/dawfs/blob/master/c9net.c
--- /dev/null
+++ b/c9.c
@@ -1,0 +1,1159 @@
+/*
+ * This is 9p client and server implementation which aims to be
+ * correct, small and secure. It's the lowest level implementation.
+ * It doesn't have much comments, mostly because it doesn't make
+ * any sense to copy-paste protocol documentation, which
+ * you can read at http://man.cat-v.org/plan_9/5/, see 'intro'.
+ */
+#include <string.h>
+#include <stdint.h>
+#include "c9.h"
+
+enum
+{+ Svver = 1<<0,
+};
+
+#define safestrlen(s) (s == NULL ? 0 : (uint32_t)strlen(s))
+#define maxread(c) (c->msize-4-4-1-2)
+#define maxwrite(c) maxread(c)
+
+static void
+w08(uint8_t **p, uint8_t x)
+{+ (*p)[0] = x;
+ *p += 1;
+}
+
+static void
+w16(uint8_t **p, uint16_t x)
+{+ (*p)[0] = x;
+ (*p)[1] = x>>8;
+ *p += 2;
+}
+
+static void
+w32(uint8_t **p, uint32_t x)
+{+ (*p)[0] = x;
+ (*p)[1] = x>>8;
+ (*p)[2] = x>>16;
+ (*p)[3] = x>>24;
+ *p += 4;
+}
+
+static void
+w64(uint8_t **p, uint64_t x)
+{+ (*p)[0] = x;
+ (*p)[1] = x>>8;
+ (*p)[2] = x>>16;
+ (*p)[3] = x>>24;
+ (*p)[4] = x>>32;
+ (*p)[5] = x>>40;
+ (*p)[6] = x>>48;
+ (*p)[7] = x>>56;
+ *p += 8;
+}
+
+static void
+wcs(uint8_t **p, const char *s, int len)
+{+ w16(p, len);
+ if(s != NULL){+ memmove(*p, s, len);
+ *p += len;
+ }
+}
+
+static uint8_t
+r08(uint8_t **p)
+{+ *p += 1;
+ return (*p)[-1];
+}
+
+static uint16_t
+r16(uint8_t **p)
+{+ *p += 2;
+ return (uint16_t)(*p)[-2]<<0 | (uint16_t)(*p)[-1]<<8;
+}
+
+static uint32_t
+r32(uint8_t **p)
+{+ return r16(p) | (uint32_t)r16(p)<<16;
+}
+
+static uint64_t
+r64(uint8_t **p)
+{+ return r32(p) | (uint64_t)r32(p)<<32;
+}
+
+static C9error
+newtag(C9ctx *c, C9ttype type, C9tag *tag)
+{+ uint32_t i;
+
+ if(type == Tversion){+ *tag = 0xffff;
+ return 0;
+ }
+
+ if(c->lowfreetag < C9maxtags){+ uint32_t d = c->lowfreetag / C9tagsbits, m = c->lowfreetag % C9tagsbits;
+ if((c->tags[d] & 1<<m) != 0){+ c->tags[d] &= ~(1<<m);
+ *tag = c->lowfreetag++;
+ return 0;
+ }
+ }
+
+ for(i = 0; i < (int)sizeof(c->tags)/sizeof(c->tags[0]); i++){+ uint32_t x, j;
+ if((x = c->tags[i]) == 0)
+ continue;
+ for(j = 0; j < C9tagsbits; j++){+ if((x & (1<<j)) != 0){+ c->tags[i] &= ~(1<<j);
+ *tag = i*C9tagsbits + j;
+ c->lowfreetag = *tag + 1;
+ return 0;
+ }
+ }
+ }
+
+ c->error("newtag: no free tags");+ return C9Etag;
+}
+
+static int
+freetag(C9ctx *c, C9tag tag)
+{+ if(tag != 0xffff){+ uint32_t d = tag / C9tagsbits, m = tag % C9tagsbits;
+ if(tag >= C9maxtags){+ c->error("freetag: invalid tag");+ return -1;
+ }
+ if((c->tags[d] & 1<<m) != 0){+ c->error("freetag: double free");+ return -1;
+ }
+ if(c->lowfreetag > tag)
+ c->lowfreetag = tag;
+ c->tags[d] |= 1<<m;
+ }
+ return 0;
+}
+
+static uint8_t *
+T(C9ctx *c, uint32_t size, C9ttype type, C9tag *tag, C9error *err)
+{+ uint8_t *p = NULL;
+
+ if(size > c->msize-4-1-2){+ c->error("T: invalid size");+ *err = C9Esize;
+ }else if((*err = newtag(c, type, tag)) == 0){+ size += 4+1+2;
+ if((p = c->begin(c, size)) == NULL){+ c->error("T: no buffer");+ freetag(c, *tag);
+ *err = C9Ebuf;
+ }else{+ *err = 0;
+ w32(&p, size);
+ w08(&p, type);
+ w16(&p, *tag);
+ }
+ }
+ return p;
+}
+
+static uint8_t *
+R(C9ctx *c, uint32_t size, C9rtype type, C9tag tag, C9error *err)
+{+ uint8_t *p = NULL;
+
+ if(size > c->msize-4-1-2){+ c->error("R: invalid size");+ *err = C9Esize;
+ }else{+ size += 4+1+2;
+ if((p = c->begin(c, size)) == NULL){+ c->error("R: no buffer");+ *err = C9Ebuf;
+ }else{+ *err = 0;
+ w32(&p, size);
+ w08(&p, type);
+ w16(&p, tag);
+ }
+ }
+ return p;
+}
+
+C9error
+c9parsedir(C9ctx *c, C9stat *stat, uint8_t **t, uint32_t *size)
+{+ uint8_t *b;
+ uint32_t cnt, sz;
+
+ if(*size < 49 || (sz = r16(t)) < 47 || *size < 2+sz)
+ goto error;
+ *size -= 2+sz;
+ *t += 6; /* skip type(2) and dev(4) */
+ stat->qid.type = r08(t);
+ stat->qid.version = r32(t);
+ stat->qid.path = r64(t);
+ stat->mode = r32(t);
+ stat->atime = r32(t);
+ stat->mtime = r32(t);
+ stat->size = r64(t);
+ sz -= 39;
+ if((cnt = r16(t)) > sz-2)
+ goto error;
+ stat->name = (char*)*t; b = *t = *t+cnt; sz -= 2+cnt;
+ if(sz < 2 || (cnt = r16(t)) > sz-2)
+ goto error;
+ stat->uid = (char*)*t; *b = 0; b = *t = *t+cnt; sz -= 2+cnt;
+ if(sz < 2 || (cnt = r16(t)) > sz-2)
+ goto error;
+ stat->gid = (char*)*t; *b = 0; b = *t = *t+cnt; sz -= 2+cnt;
+ if(sz < 2 || (cnt = r16(t)) > sz-2)
+ goto error;
+ stat->muid = memmove(*t-1, *t, cnt); *b = stat->muid[cnt] = 0; *t = *t+cnt; sz -= 2+cnt;
+ *t += sz;
+ return 0;
+error:
+ c->error("c9parsedir: invalid size");+ return C9Epkt;
+}
+
+C9error
+c9version(C9ctx *c, C9tag *tag, uint32_t msize)
+{+ uint8_t *b;
+ C9error err;
+
+ if(msize < C9minmsize){+ c->error("c9version: msize too small");+ return C9Einit;
+ }
+ memset(c->tags, 0xff, sizeof(c->tags));
+ memset(c->flush, 0xff, sizeof(c->flush));
+ c->lowfreetag = 0;
+ c->msize = msize;
+
+ if((b = T(c, 4+2+6, Tversion, tag, &err)) != NULL){+ w32(&b, msize);
+ wcs(&b, "9P2000", 6);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9auth(C9ctx *c, C9tag *tag, C9fid afid, const char *uname, const char *aname)
+{+ uint8_t *b;
+ uint32_t ulen = safestrlen(uname), alen = safestrlen(aname);
+ C9error err;
+
+ if(ulen > C9maxstr || alen > C9maxstr){+ c->error("c9auth: string too long");+ return C9Estr;
+ }
+ if((b = T(c, 4+2+ulen+2+alen, Tauth, tag, &err)) != NULL){+ w32(&b, afid);
+ wcs(&b, uname, ulen);
+ wcs(&b, aname, alen);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9flush(C9ctx *c, C9tag *tag, C9tag oldtag)
+{+ uint8_t *b;
+ C9error err;
+ int i;
+
+ for(i = 0; i < C9maxflush && c->flush[i] != (uint32_t)~0; i++);
+ if(i == C9maxflush){+ c->error("c9flush: no free flush slots");+ return C9Eflush;
+ }
+ if((b = T(c, 2, Tflush, tag, &err)) != NULL){+ w16(&b, oldtag);
+ err = c->end(c);
+ if(err == 0)
+ c->flush[i] = (uint32_t)oldtag<<16 | *tag;
+ }
+ return err;
+}
+
+C9error
+c9attach(C9ctx *c, C9tag *tag, C9fid fid, C9fid afid, const char *uname, const char *aname)
+{+ uint32_t ulen = safestrlen(uname), alen = safestrlen(aname);
+ uint8_t *b;
+ C9error err;
+
+ if(ulen > C9maxstr || alen > C9maxstr){+ c->error("c9attach: string too long");+ return C9Estr;
+ }
+ if((b = T(c, 4+4+2+ulen+2+alen, Tattach, tag, &err)) != NULL){+ w32(&b, fid);
+ w32(&b, afid);
+ wcs(&b, uname, ulen);
+ wcs(&b, aname, alen);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9walk(C9ctx *c, C9tag *tag, C9fid fid, C9fid newfid, const char *path[])
+{+ uint32_t i, j, sz;
+ uint32_t len[C9maxpathel];
+ uint8_t *b;
+ C9error err;
+
+ for(sz = i = 0; i < (int)sizeof(len)/sizeof(len[0]) && path[i] != NULL; i++){+ len[i] = safestrlen(path[i]);
+ if(len[i] == 0 || len[i] > C9maxstr){+ c->error("c9walk: path element too long");+ return C9Epath;
+ }
+ sz += 2 + len[i];
+ }
+ if(path[i] != NULL || i == 0){+ c->error("c9walk: invalid elements !(0 < %d <= %d)", i, C9maxpathel);+ return C9Epath;
+ }
+
+ if((b = T(c, 4+4+2+sz, Twalk, tag, &err)) != NULL){+ w32(&b, fid);
+ w32(&b, newfid);
+ w16(&b, i);
+ for(j = 0; j < i; j++)
+ wcs(&b, path[j], len[j]);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9open(C9ctx *c, C9tag *tag, C9fid fid, C9mode mode)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4+1, Topen, tag, &err)) != NULL){+ w32(&b, fid);
+ w08(&b, mode);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9create(C9ctx *c, C9tag *tag, C9fid fid, const char *name, uint32_t perm, C9mode mode)
+{+ uint32_t nlen = strlen(name);
+ uint8_t *b;
+ C9error err;
+
+ if(nlen == 0 || nlen > C9maxstr){+ c->error("c9create: invalid name");+ return C9Epath;
+ }
+ if((b = T(c, 4+2+nlen+4+1, Tcreate, tag, &err)) != NULL){+ w32(&b, fid);
+ wcs(&b, name, nlen);
+ w32(&b, perm);
+ w08(&b, mode);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9read(C9ctx *c, C9tag *tag, C9fid fid, uint64_t offset, uint32_t count)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4+8+4, Tread, tag, &err)) != NULL){+ w32(&b, fid);
+ w64(&b, offset);
+ w32(&b, count);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9write(C9ctx *c, C9tag *tag, C9fid fid, uint64_t offset, const void *in, uint32_t count)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4+8+4+count, Twrite, tag, &err)) != NULL){+ w32(&b, fid);
+ w64(&b, offset);
+ w32(&b, count);
+ memmove(b, in, count);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9wrstr(C9ctx *c, C9tag *tag, C9fid fid, const char *s)
+{+ return c9write(c, tag, fid, 0, s, strlen(s));
+}
+
+C9error
+c9clunk(C9ctx *c, C9tag *tag, C9fid fid)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4, Tclunk, tag, &err)) != NULL){+ w32(&b, fid);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9remove(C9ctx *c, C9tag *tag, C9fid fid)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4, Tremove, tag, &err)) != NULL){+ w32(&b, fid);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9stat(C9ctx *c, C9tag *tag, C9fid fid)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = T(c, 4, Tstat, tag, &err)) != NULL){+ w32(&b, fid);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9wstat(C9ctx *c, C9tag *tag, C9fid fid, const C9stat *s)
+{+ uint32_t nlen = safestrlen(s->name), ulen = safestrlen(s->uid), glen = safestrlen(s->gid);
+ uint32_t unusedsz = 2+4+13, statsz = unusedsz+4+4+4+8+2+nlen+2+ulen+2+glen+2;
+ uint8_t *b;
+ C9error err;
+
+ if(nlen == 0 || nlen > C9maxstr){+ c->error("c9wstat: invalid name");+ return C9Epath;
+ }
+ if(ulen > C9maxstr || glen > C9maxstr){+ c->error("c9wstat: string too long");+ return C9Estr;
+ }
+ if((b = T(c, 4+2+2+statsz, Twstat, tag, &err)) != NULL){+ w32(&b, fid);
+ w16(&b, statsz+2);
+ w16(&b, statsz);
+ memset(b, 0xff, unusedsz); /* leave type(2), dev(4) and qid(13) unchanged */
+ b += unusedsz;
+ w32(&b, s->mode);
+ w32(&b, s->atime);
+ w32(&b, s->mtime);
+ w64(&b, s->size);
+ wcs(&b, s->name, nlen);
+ wcs(&b, s->uid, ulen);
+ wcs(&b, s->gid, glen);
+ wcs(&b, NULL, 0); /* muid unchanged */
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+c9proc(C9ctx *c)
+{+ uint32_t i, sz, cnt, msize;
+ uint8_t *b;
+ int err;
+ C9r r;
+
+ err = -1;
+ if((b = c->read(c, 4, &err)) == NULL){+ if(err != 0)
+ c->error("c9proc: short read");+ return err == 0 ? 0 : C9Epkt;
+ }
+
+ sz = r32(&b);
+ if(sz < 7 || sz > c->msize){+ c->error("c9proc: invalid packet size !(7 <= %u <= %u)", sz, c->msize);+ return C9Epkt;
+ }
+ sz -= 4;
+ err = -1;
+ if((b = c->read(c, sz, &err)) == NULL){+ if(err != 0)
+ c->error("c9proc: short read");+ return err == 0 ? 0 : C9Epkt;
+ }
+
+ r.type = r08(&b);
+ r.tag = r16(&b);
+ if(r.type != Rversion){+ if(r.tag >= C9maxtags){+ c->error("c9proc: invalid tag 0x%x", r.tag);+ return C9Epkt;
+ }
+ if(freetag(c, r.tag) != 0)
+ return C9Etag;
+ }
+ sz -= 3;
+ r.numqid = 0;
+
+ switch(r.type){+ case Rread:
+ if(sz < 4 || (cnt = r32(&b)) > sz-4)
+ goto error;
+ r.read.data = b;
+ r.read.size = cnt;
+ c->r(c, &r);
+ break;
+
+ case Rwrite:
+ if(sz < 4 || (cnt = r32(&b)) > c->msize)
+ goto error;
+ r.write.size = cnt;
+ c->r(c, &r);
+ break;
+
+ case Rwalk:
+ if(sz < 2+13 || (cnt = r16(&b))*13 > sz-2)
+ goto error;
+ if(cnt > C9maxpathel){+ c->error("c9proc: Rwalk !(%d <= %d)", cnt, C9maxpathel);+ return C9Epath;
+ }
+ for(i = 0; i < cnt; i++){+ r.qid[i].type = r08(&b);
+ r.qid[i].version = r32(&b);
+ r.qid[i].path = r64(&b);
+ }
+ r.numqid = cnt;
+ c->r(c, &r);
+ break;
+
+ case Rstat:
+ b += 2; sz -= 2;
+ if((err = c9parsedir(c, &r.stat, &b, &sz)) != 0){+ c->error("c9proc");+ return err;
+ }
+ r.numqid = 1;
+ c->r(c, &r);
+ break;
+
+ case Rflush:
+ for(i = 0; i < C9maxflush; i++){+ if((c->flush[i] & 0xffff) == r.tag){+ freetag(c, c->flush[i]>>16);
+ c->flush[i] = 0xffffffff;
+ break;
+ }
+ }
+ /* fallthrough */
+ case Rclunk:
+ case Rremove:
+ case Rwstat:
+ c->r(c, &r);
+ break;
+
+ case Ropen:
+ case Rcreate:
+ if(sz < 17)
+ goto error;
+ r.qid[0].type = r08(&b);
+ r.qid[0].version = r32(&b);
+ r.qid[0].path = r64(&b);
+ r.iounit = r32(&b);
+ r.numqid = 1;
+ c->r(c, &r);
+ break;
+
+ case Rerror:
+ if(sz < 2 || (cnt = r16(&b)) > sz-2)
+ goto error;
+ r.error = memmove(b-1, b, cnt);
+ r.error[cnt] = 0;
+ c->r(c, &r);
+ break;
+
+ case Rauth:
+ case Rattach:
+ if(sz < 13)
+ goto error;
+ r.qid[0].type = r08(&b);
+ r.qid[0].version = r32(&b);
+ r.qid[0].path = r64(&b);
+ r.numqid = 1;
+ c->r(c, &r);
+ break;
+
+ case Rversion:
+ if(sz < 4+2 || (msize = r32(&b)) < C9minmsize || (cnt = r16(&b)) > sz-4-2)
+ goto error;
+ if(cnt < 6 || memcmp(b, "9P2000", 6) != 0){+ c->error("invalid version");+ return C9Ever;
+ }
+ if(msize < c->msize)
+ c->msize = msize;
+ c->r(c, &r);
+ break;
+
+ default:
+ goto error;
+ }
+ return 0;
+error:
+ c->error("c9proc: invalid packet (type=%d)", r.type);+ return C9Epkt;
+}
+
+C9error
+s9version(C9ctx *c)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 4+2+6, Rversion, 0xffff, &err)) != NULL){+ w32(&b, c->msize);
+ wcs(&b, "9P2000", 6);
+ err = c->end(c);
+ };
+ return err;
+}
+
+C9error
+s9auth(C9ctx *c, C9tag tag, const C9qid *aqid)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 13, Rauth, tag, &err)) != NULL){+ w08(&b, aqid->type);
+ w32(&b, aqid->version);
+ w64(&b, aqid->path);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9error(C9ctx *c, C9tag tag, const char *ename)
+{+ uint32_t len = safestrlen(ename);
+ uint8_t *b;
+ C9error err;
+
+ if(len > C9maxstr){+ c->error("s9error: invalid ename");+ return C9Estr;
+ }
+ if((b = R(c, 2+len, Rerror, tag, &err)) != NULL){+ wcs(&b, ename, len);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9attach(C9ctx *c, C9tag tag, const C9qid *qid)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 13, Rattach, tag, &err)) != NULL){+ w08(&b, qid->type);
+ w32(&b, qid->version);
+ w64(&b, qid->path);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9flush(C9ctx *c, C9tag tag)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 0, Rflush, tag, &err)) != NULL)
+ err = c->end(c);
+ return err;
+}
+
+C9error
+s9walk(C9ctx *c, C9tag tag, C9qid *qids[])
+{+ uint32_t i, n;
+ uint8_t *b;
+ C9error err;
+
+ for(n = 0; n < C9maxpathel && qids[n] != NULL; n++);
+ if(n > C9maxpathel){+ c->error("s9walk: invalid elements !(0 <= %d <= %d)", n, C9maxpathel);+ return C9Epath;
+ }
+
+ if((b = R(c, 2+n*13, Rwalk, tag, &err)) != NULL){+ w16(&b, n);
+ for(i = 0; i < n; i++){+ w08(&b, qids[i]->type);
+ w32(&b, qids[i]->version);
+ w64(&b, qids[i]->path);
+ }
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9open(C9ctx *c, C9tag tag, const C9qid *qid, uint32_t iounit)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 13+4, Ropen, tag, &err)) != NULL){+ w08(&b, qid->type);
+ w32(&b, qid->version);
+ w64(&b, qid->path);
+ w32(&b, iounit);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9create(C9ctx *c, C9tag tag, const C9qid *qid, uint32_t iounit)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 13+4, Rcreate, tag, &err)) != NULL){+ w08(&b, qid->type);
+ w32(&b, qid->version);
+ w64(&b, qid->path);
+ w32(&b, iounit);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9read(C9ctx *c, C9tag tag, const void *data, uint32_t size)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 4+size, Rread, tag, &err)) != NULL){+ w32(&b, size);
+ memmove(b, data, size);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9write(C9ctx *c, C9tag tag, uint32_t size)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 4, Rwrite, tag, &err)) != NULL){+ w32(&b, size);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9readdir(C9ctx *c, C9tag tag, C9stat *st[], int *num, uint64_t *offset, uint32_t size)
+{+ uint8_t *b;
+ const C9stat *s;
+ uint32_t nlen, ulen, glen, mulen, m, n;
+ C9error err;
+ int i;
+
+ if(size > c->msize-4-1-2)
+ size = c->msize-4-1-2;
+
+ m = 0;
+ for(i = 0; i < *num; i++){+ s = st[i];
+ nlen = safestrlen(s->name);
+ ulen = safestrlen(s->uid);
+ glen = safestrlen(s->gid);
+ mulen = safestrlen(s->muid);
+
+ if(nlen == 0 || nlen > C9maxstr){+ c->error("s9readdir: invalid name");+ return C9Epath;
+ }
+ if(ulen > C9maxstr || glen > C9maxstr || mulen > C9maxstr){+ c->error("s9readdir: string too long");+ return C9Estr;
+ }
+
+ n = 2 + 2+4+13+4+4+4+8+2+nlen+2+ulen+2+glen+2+mulen;
+ if(4+m+n > size)
+ break;
+ m += n;
+ }
+
+ if((b = R(c, 4+m, Rread, tag, &err)) != NULL){+ *num = i;
+ w32(&b, m);
+ for(i = 0; i < *num; i++){+ s = st[i];
+ nlen = safestrlen(s->name);
+ ulen = safestrlen(s->uid);
+ glen = safestrlen(s->gid);
+ mulen = safestrlen(s->muid);
+ w16(&b, 2+4+13+4+4+4+8+2+nlen+2+ulen+2+glen+2+mulen);
+ w16(&b, 0xffff); /* type */
+ w32(&b, 0xffffffff); /* dev */
+ w08(&b, s->qid.type);
+ w32(&b, s->qid.version);
+ w64(&b, s->qid.path);
+ w32(&b, s->mode);
+ w32(&b, s->atime);
+ w32(&b, s->mtime);
+ w64(&b, s->size);
+ wcs(&b, s->name, nlen);
+ wcs(&b, s->uid, ulen);
+ wcs(&b, s->gid, glen);
+ wcs(&b, s->muid, mulen);
+ }
+ err = c->end(c);
+ if(err == 0)
+ *offset += m;
+ }
+ return err;
+}
+
+C9error
+s9clunk(C9ctx *c, C9tag tag)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 0, Rclunk, tag, &err)) != NULL)
+ err = c->end(c);
+ return err;
+}
+
+C9error
+s9remove(C9ctx *c, C9tag tag)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 0, Rremove, tag, &err)) != NULL)
+ err = c->end(c);
+ return err;
+}
+
+C9error
+s9stat(C9ctx *c, C9tag tag, const C9stat *s)
+{+ uint32_t nlen = safestrlen(s->name), ulen = safestrlen(s->uid);
+ uint32_t glen = safestrlen(s->gid), mulen = safestrlen(s->name);
+ uint32_t statsz = 2+4+13+4+4+4+8+2+nlen+2+ulen+2+glen+2+mulen;
+ uint8_t *b;
+ C9error err;
+
+ if(nlen == 0 || nlen > C9maxstr){+ c->error("s9stat: invalid name");+ return C9Epath;
+ }
+ if(ulen > C9maxstr || glen > C9maxstr || mulen > C9maxstr){+ c->error("s9stat: string too long");+ return C9Estr;
+ }
+
+ if((b = R(c, 2+2+statsz, Rstat, tag, &err)) != NULL){+ w16(&b, statsz+2);
+ w16(&b, statsz);
+ w16(&b, 0xffff); /* type */
+ w32(&b, 0xffffffff); /* dev */
+ w08(&b, s->qid.type);
+ w32(&b, s->qid.version);
+ w64(&b, s->qid.path);
+ w32(&b, s->mode);
+ w32(&b, s->atime);
+ w32(&b, s->mtime);
+ w64(&b, s->size);
+ wcs(&b, s->name, nlen);
+ wcs(&b, s->uid, ulen);
+ wcs(&b, s->gid, glen);
+ wcs(&b, s->muid, mulen);
+ err = c->end(c);
+ }
+ return err;
+}
+
+C9error
+s9wstat(C9ctx *c, C9tag tag)
+{+ uint8_t *b;
+ C9error err;
+
+ if((b = R(c, 0, Rwstat, tag, &err)) != NULL)
+ err = c->end(c);
+ return err;
+}
+
+C9error
+s9proc(C9ctx *c)
+{+ uint32_t i, sz, cnt, n, msize;
+ int readerr;
+ uint8_t *b;
+ C9error err;
+ C9t t;
+
+ readerr = -1;
+ if((b = c->read(c, 4, &readerr)) == NULL){+ if(readerr != 0)
+ c->error("s9proc: short read");+ return readerr == 0 ? 0 : C9Epkt;
+ }
+
+ sz = r32(&b);
+ if(sz < 7 || sz > c->msize){+ c->error("s9proc: invalid packet size !(7 <= %u <= %u)", sz, c->msize);+ return C9Epkt;
+ }
+ sz -= 4;
+ readerr = -1;
+ if((b = c->read(c, sz, &readerr)) == NULL){+ if(readerr != 0)
+ c->error("s9proc: short read");+ return readerr == 0 ? 0 : C9Epkt;
+ }
+
+ t.type = r08(&b);
+ t.tag = r16(&b);
+ sz -= 3;
+
+ if((c->svflags & Svver) == 0 && t.type != Tversion){+ c->error("s9proc: expected Tversion, got %d", t.type);+ return C9Epkt;
+ }
+
+ switch(t.type){+ case Tread:
+ if(sz < 4+8+4)
+ goto error;
+ t.fid = r32(&b);
+ t.read.offset = r64(&b);
+ t.read.size = r32(&b);
+ if(t.read.size > maxread(c))
+ t.read.size = maxread(c);
+ c->t(c, &t);
+ break;
+
+ case Twrite:
+ if(sz < 4+8+4)
+ goto error;
+ t.fid = r32(&b);
+ t.write.offset = r64(&b);
+ if((t.write.size = r32(&b)) < sz-4-8-4)
+ goto error;
+ if(t.write.size > maxwrite(c))
+ t.write.size = maxwrite(c);
+ t.write.data = b;
+ c->t(c, &t);
+ break;
+
+ case Tclunk:
+ case Tstat:
+ case Tremove:
+ if(sz < 4)
+ goto error;
+ t.fid = r32(&b);
+ c->t(c, &t);
+ break;
+
+ case Twalk:
+ if(sz < 4+4+2)
+ goto error;
+ t.fid = r32(&b);
+ t.walk.newfid = r32(&b);
+ if((n = r16(&b)) > 16){+ c->error("s9proc: Twalk !(%d <= 16)", n);+ return C9Epath;
+ }
+ sz -= 4+4+2;
+ if(n > 0){+ for(i = 0; i < n; i++){+ if(sz < 2 || (cnt = r16(&b)) > sz-2)
+ goto error;
+ if(cnt < 1){+ c->error("s9proc: Twalk invalid element [%d]", i);+ return C9Epath;
+ }
+ b[-2] = 0;
+ t.walk.wname[i] = (char*)b;
+ b += cnt;
+ sz -= 2 + cnt;
+ }
+ memmove(t.walk.wname[i-1]-1, t.walk.wname[i-1], (char*)b - t.walk.wname[i-1]);
+ t.walk.wname[i-1]--;
+ b[-1] = 0;
+ }else
+ i = 0;
+ t.walk.wname[i] = NULL;
+ c->t(c, &t);
+ break;
+
+ case Topen:
+ if(sz < 4+1)
+ goto error;
+ t.fid = r32(&b);
+ t.open.mode = r08(&b);
+ c->t(c, &t);
+ break;
+
+ case Twstat:
+ if(sz < 4+2)
+ goto error;
+ t.fid = r32(&b);
+ if((cnt = r16(&b)) > sz-4)
+ goto error;
+ if((err = c9parsedir(c, &t.wstat, &b, &cnt)) != 0){+ c->error("s9proc");+ return err;
+ }
+ c->t(c, &t);
+ break;
+
+ case Tcreate:
+ if(sz < 4+2+4+1)
+ goto error;
+ t.fid = r32(&b);
+ if((cnt = r16(&b)) < 1 || cnt > sz-4-2-4-1)
+ goto error;
+ t.create.name = (char*)b;
+ b += cnt;
+ t.create.perm = r32(&b);
+ t.create.mode = r08(&b);
+ t.create.name[cnt] = 0;
+ c->t(c, &t);
+ break;
+
+ case Tflush:
+ if(sz < 2)
+ goto error;
+ t.flush.oldtag = r16(&b);
+ c->t(c, &t);
+ break;
+
+ case Tversion:
+ if(sz < 4+2 || (msize = r32(&b)) < C9minmsize || (cnt = r16(&b)) > sz-4-2)
+ goto error;
+ if(cnt < 6 || memcmp(b, "9P2000", 6) != 0){+ if((b = R(c, 4+2+7, Rversion, 0xffff, &err)) != NULL){+ w32(&b, 0);
+ wcs(&b, "unknown", 7);
+ err = c->end(c);
+ c->error("s9proc: invalid version");+ }
+ return C9Ever;
+ }
+ if(msize < c->msize)
+ c->msize = msize;
+ c->svflags |= Svver;
+ c->t(c, &t);
+ break;
+
+ case Tattach:
+ if(sz < 4+4+2+2)
+ goto error;
+ t.fid = r32(&b);
+ t.attach.afid = r32(&b);
+ cnt = r16(&b);
+ sz -= 4+4+2;
+ if(cnt+2 > sz)
+ goto error;
+ t.attach.uname = (char*)b;
+ b += cnt;
+ cnt = r16(&b);
+ b[-2] = 0;
+ sz -= cnt+2;
+ if(cnt > sz)
+ goto error;
+ memmove(b-1, b, cnt);
+ t.attach.aname = (char*)b-1;
+ t.attach.aname[cnt] = 0;
+ c->t(c, &t);
+ break;
+
+ case Tauth:
+ if(sz < 4+2+2)
+ goto error;
+ t.auth.afid = r32(&b);
+ cnt = r16(&b);
+ sz -= 4+2;
+ if(cnt+2 > sz)
+ goto error;
+ t.auth.uname = (char*)b;
+ b += cnt;
+ cnt = r16(&b);
+ b[-2] = 0;
+ sz -= cnt+2;
+ if(cnt > sz)
+ goto error;
+ memmove(b-1, b, cnt);
+ t.auth.aname = (char*)b-1;
+ t.auth.aname[cnt] = 0;
+ c->t(c, &t);
+ break;
+
+ default:
+ goto error;
+ }
+ return 0;
+error:
+ c->error("s9proc: invalid packet (type=%d)", t.type);+ return C9Epkt;
+}
--- /dev/null
+++ b/c9.h
@@ -1,0 +1,350 @@
+struct C9aux;
+
+typedef struct C9r C9r;
+typedef struct C9t C9t;
+typedef struct C9stat C9stat;
+typedef struct C9ctx C9ctx;
+typedef struct C9qid C9qid;
+typedef enum C9error C9error;
+typedef enum C9mode C9mode;
+typedef enum C9rtype C9rtype;
+typedef enum C9ttype C9ttype;
+typedef enum C9qt C9qt;
+typedef uint32_t C9fid;
+typedef uint16_t C9tag;
+
+/* Stat field is not changed if it's set to this value when calling c9wstat. */
+#define C9nochange (~0)
+
+/* Special fid used with auth/attach to basically avoid authentication. */
+#define C9nofid ((C9fid)~0)
+
+/* C9modes for opening a file. */
+enum C9mode
+{+ C9read = 0,
+ C9write = 1,
+ C9rdwr = 2,
+ C9exec = 3,
+ C9trunc = 0x10,
+ C9rclose = 0x40,
+};
+
+enum C9perm
+{+ /* User/owner. */
+ C9permur = 1<<8, /* Readable. */
+ C9permuw = 1<<7, /* Writable. */
+ C9permux = 1<<6, /* Executable. */
+
+ /* Group. */
+ C9permgr = 1<<5,
+ C9permgw = 1<<4,
+ C9permgx = 1<<3,
+
+ /* Other. */
+ C9permor = 1<<2,
+ C9permow = 1<<1,
+ C9permox = 1<<0,
+};
+
+/* Directory. */
+#define C9permdir 0x80000000
+
+/* Bitmask of stat.mode. */
+#define C9stdir 0x80000000
+#define C9stappend 0x40000000
+#define C9stexcl 0x20000000
+#define C9sttmp 0x04000000
+
+/* Limits. */
+enum
+{+ C9maxtags = 64, /* Maximal number of outstanding requests. [1-65535] */
+ C9maxflush = 8, /* Maximal number of outstanding flushes. [1-65535] */
+ C9maxstr = 0xffff, /* Maximal string length. [1-65535] */
+ C9minmsize = 4096, /* Minimal sane msize. [4096-...] */
+ C9maxpathel = 16, /* Maximal number of elements in a path. Do not change. */
+};
+
+/* Errors. */
+enum C9error
+{+ C9Einit = -1, /* Initialization failed. */
+ C9Ever = -2, /* Protocol version doesn't match. */
+ C9Epkt = -3, /* Incoming packet error. */
+ C9Etag = -4, /* No free tags or bad tag. */
+ C9Ebuf = -5, /* No buffer space enough for a message. */
+ C9Epath = -6, /* Path is too long or just invalid. */
+ C9Eflush = -7, /* Limit of outstanding flushes reached. */
+ C9Esize = -8, /* Can't fit data in one message. */
+ C9Estr = -9 /* Bad string. */
+};
+
+/* Request types. */
+enum C9ttype
+{+ Tversion = 100,
+ Tauth = 102,
+ Tattach = 104,
+ Tflush = 108,
+ Twalk = 110,
+ Topen = 112,
+ Tcreate = 114,
+ Tread = 116,
+ Twrite = 118,
+ Tclunk = 120,
+ Tremove = 122,
+ Tstat = 124,
+ Twstat = 126
+};
+
+/* Response types. */
+enum C9rtype
+{+ Rversion = 101,
+ Rauth = 103,
+ Rattach = 105,
+ Rerror = 107,
+ Rflush = 109,
+ Rwalk = 111,
+ Ropen = 113,
+ Rcreate = 115,
+ Rread = 117,
+ Rwrite = 119,
+ Rclunk = 121,
+ Rremove = 123,
+ Rstat = 125,
+ Rwstat = 127
+};
+
+/* Unique file id type. */
+enum C9qt
+{+ C9qtdir = 1<<7,
+ C9qtappend = 1<<6,
+ C9qtexcl = 1<<5,
+ C9qtauth = 1<<3,
+ C9qttmp = 1<<2,
+ C9qtfile = 0
+};
+
+/* Unique file id. */
+struct C9qid
+{+ uint64_t path;
+ uint32_t version;
+ C9qt type;
+};
+
+/*
+ * File stats. Version and muid are ignored on wstat. Dmdir bit
+ * change in mode won't work on wstat. Set any integer field to
+ * C9nochange to keep it unchanged on wstat. Set any string to NULL to
+ * keep it unchanged. Strings can be empty (""), but never NULL after+ * stat call.
+ */
+struct C9stat
+{+ uint64_t size; /* Size of the file (in bytes). */
+ char *name; /* Name of the file. */
+ char *uid; /* Owner of the file. */
+ char *gid; /* Group of the file. */
+ char *muid; /* The user who modified the file last. */
+ C9qid qid; /* Same as qid[0]. */
+ uint32_t mode; /* Permissions. See C9st* and C9perm. */
+ uint32_t atime; /* Last access time. */
+ uint32_t mtime; /* Last modification time. */
+};
+
+/* Response data. */
+struct C9r
+{+ union
+ {+ char *error;
+
+ struct
+ {+ uint8_t *data;
+ uint32_t size;
+ }read;
+
+ struct
+ {+ uint32_t size;
+ }write;
+
+ /* File stats (only valid if type is Rstat). */
+ C9stat stat;
+
+ /*
+ * Qid(s). qid[0] is valid for auth/attach/create/stat/open.
+ * More ids may be a result of a walk, see numqid.
+ */
+ C9qid qid[C9maxpathel];
+ };
+ C9rtype type; /* Response type. */
+
+ /*
+ * If not zero, is the maximum number of bytes that are guaranteed
+ * to be read or written atomically, without breaking into multiple
+ * messages.
+ */
+ uint32_t iounit;
+
+ int numqid; /* Number of valid unique ids in qid array. */
+ C9tag tag; /* Tag number. */
+};
+
+/* Request data. */
+struct C9t
+{+ C9ttype type;
+ C9tag tag;
+ union
+ {+ struct
+ {+ char *uname;
+ char *aname;
+ C9fid afid;
+ }attach;
+
+ struct
+ {+ char *uname;
+ char *aname;
+ C9fid afid;
+ }auth;
+
+ struct
+ {+ char *name;
+ uint32_t perm;
+ C9mode mode;
+ }create;
+
+ struct
+ {+ C9tag oldtag;
+ }flush;
+
+ struct
+ {+ C9mode mode;
+ }open;
+
+ struct
+ {+ uint64_t offset;
+ uint32_t size;
+ }read;
+
+ struct
+ {+ char *wname[C9maxpathel+1]; /* wname[16] is always NULL */
+ C9fid newfid;
+ }walk;
+
+ struct
+ {+ uint64_t offset;
+ uint8_t *data;
+ uint32_t size;
+ }write;
+
+ C9stat wstat;
+ };
+ C9fid fid;
+};
+
+enum
+{+ C9tagsbits = sizeof(uint32_t) * 8,
+};
+
+struct C9ctx
+{+ /*
+ * Should return a pointer to the data (exactly 'size' bytes) read.
+ * Set 'err' to non-zero and return NULL in case of error.
+ * 'err' set to zero (no error) should be used to return from c9process
+ * early (timeout on read to do non-blocking operations, for example).
+ */
+ uint8_t *(*read)(C9ctx *ctx, uint32_t size, int *err) __attribute__((nonnull(1, 3)));
+
+ /* Should return a buffer to store 'size' bytes. Nil means no memory. */
+ uint8_t *(*begin)(C9ctx *ctx, uint32_t size) __attribute__((nonnull(1)));
+
+ /*
+ * Marks the end of a message. Callback may decide if any accumulated
+ * messages should be sent to the server/client.
+ */
+ int (*end)(C9ctx *ctx) __attribute__((nonnull(1)));
+
+ /* Callback called every time a new R-message is received. */
+ void (*r)(C9ctx *ctx, C9r *r) __attribute__((nonnull(1, 2)));
+
+ /* Callback called every time a new T-message is received. */
+ void (*t)(C9ctx *ctx, C9t *t) __attribute__((nonnull(1, 2)));
+
+ /* Callback for error messages. */
+ void (*error)(const char *fmt, ...) __attribute__((nonnull(1)));
+
+ /* Auxiliary data, can be used by any of above callbacks. */
+ struct C9aux *aux;
+
+ /* private stuff */
+ uint32_t msize;
+ uint32_t flush[C9maxflush];
+ uint32_t tags[C9maxtags/C9tagsbits];
+ union
+ {+ C9tag lowfreetag;
+ uint16_t svflags;
+ };
+};
+
+/* Parse one directory entry. */
+extern C9error c9parsedir(C9ctx *c, C9stat *stat, uint8_t **data, uint32_t *size) __attribute__((nonnull(1, 2, 3)));
+
+extern C9error c9version(C9ctx *c, C9tag *tag, uint32_t msize) __attribute__((nonnull(1, 2)));
+extern C9error c9auth(C9ctx *c, C9tag *tag, C9fid afid, const char *uname, const char *aname) __attribute__((nonnull(1, 2)));
+extern C9error c9flush(C9ctx *c, C9tag *tag, C9tag oldtag) __attribute__((nonnull(1, 2)));
+extern C9error c9attach(C9ctx *c, C9tag *tag, C9fid fid, C9fid afid, const char *uname, const char *aname) __attribute__((nonnull(1, 2)));
+extern C9error c9walk(C9ctx *c, C9tag *tag, C9fid fid, C9fid newfid, const char *path[]) __attribute__((nonnull(1, 2, 5)));
+extern C9error c9open(C9ctx *c, C9tag *tag, C9fid fid, C9mode mode) __attribute__((nonnull(1, 2)));
+extern C9error c9create(C9ctx *c, C9tag *tag, C9fid fid, const char *name, uint32_t perm, C9mode mode) __attribute__((nonnull(1, 2, 4)));
+extern C9error c9read(C9ctx *c, C9tag *tag, C9fid fid, uint64_t offset, uint32_t count) __attribute__((nonnull(1, 2)));
+extern C9error c9write(C9ctx *c, C9tag *tag, C9fid fid, uint64_t offset, const void *in, uint32_t count) __attribute__((nonnull(1, 2, 5)));
+extern C9error c9wrstr(C9ctx *c, C9tag *tag, C9fid fid, const char *s) __attribute__((nonnull(1, 2, 4)));
+extern C9error c9clunk(C9ctx *c, C9tag *tag, C9fid fid) __attribute__((nonnull(1, 2)));
+extern C9error c9remove(C9ctx *c, C9tag *tag, C9fid fid) __attribute__((nonnull(1, 2)));
+extern C9error c9stat(C9ctx *c, C9tag *tag, C9fid fid) __attribute__((nonnull(1, 2)));
+extern C9error c9wstat(C9ctx *c, C9tag *tag, C9fid fid, const C9stat *s) __attribute__((nonnull(1, 2, 4)));
+
+/*
+ * Wait until a response comes and process it. If the function returns
+ * any error, context must be treated as 'broken' and no subsequent calls
+ * should be made without reinitialization (c9version).
+ */
+extern C9error c9proc(C9ctx *c) __attribute__((nonnull(1)));
+
+extern C9error s9version(C9ctx *c) __attribute__((nonnull(1)));
+extern C9error s9auth(C9ctx *c, C9tag tag, const C9qid *aqid) __attribute__((nonnull(1, 3)));
+extern C9error s9error(C9ctx *c, C9tag tag, const char *err) __attribute__((nonnull(1)));
+extern C9error s9attach(C9ctx *c, C9tag tag, const C9qid *qid) __attribute__((nonnull(1, 3)));
+extern C9error s9flush(C9ctx *c, C9tag tag) __attribute__((nonnull(1)));
+extern C9error s9walk(C9ctx *c, C9tag tag, C9qid *qids[]) __attribute__((nonnull(1, 3)));
+extern C9error s9open(C9ctx *c, C9tag tag, const C9qid *qid, uint32_t iounit) __attribute__((nonnull(1, 3)));
+extern C9error s9create(C9ctx *c, C9tag tag, const C9qid *qid, uint32_t iounit) __attribute__((nonnull(1, 3)));
+extern C9error s9read(C9ctx *c, C9tag tag, const void *data, uint32_t size) __attribute__((nonnull(1, 3)));
+extern C9error s9readdir(C9ctx *c, C9tag tag, C9stat *st[], int *num, uint64_t *offset, uint32_t size) __attribute__((nonnull(1, 3, 4)));
+extern C9error s9write(C9ctx *c, C9tag tag, uint32_t size) __attribute__((nonnull(1)));
+extern C9error s9clunk(C9ctx *c, C9tag tag) __attribute__((nonnull(1)));
+extern C9error s9remove(C9ctx *c, C9tag tag) __attribute__((nonnull(1)));
+extern C9error s9stat(C9ctx *c, C9tag tag, const C9stat *s) __attribute__((nonnull(1, 3)));
+extern C9error s9wstat(C9ctx *c, C9tag tag) __attribute__((nonnull(1)));
+
+extern C9error s9proc(C9ctx *c) __attribute__((nonnull(1)));