WebSVN – planix.SVN – Blame – /os/branches/feature_unix/sys/src/cmd/unix/u9fs/u9fs.c

Rev	Author	Line No.	Line
2	-	1	`/* already in plan9.h #include <sys/types.h> // for struct passwd, struct group, struct stat ... */`
		2	`/* plan9.h is first to get the large file support definitions as early as possible */`
		3	`#include <plan9.h>`
		4	`#include <sys/stat.h> /* for stat, umask */`
		5	`#include <stdlib.h> /* for malloc */`
		6	`#include <string.h> /* for strcpy, memmove */`
		7	`#include <pwd.h> /* for getpwnam, getpwuid */`
		8	`#include <grp.h> /* for getgrnam, getgrgid */`
		9	`#include <unistd.h> /* for gethostname, pread, pwrite, read, write */`
		10	`#include <utime.h> /* for utime */`
		11	`#include <dirent.h> /* for readdir */`
		12	`#include <errno.h> /* for errno */`
		13	`#include <stdio.h> /* for remove [sic] */`
		14	`#include <fcntl.h> /* for O_RDONLY, etc. */`
		15
		16	`#include <sys/socket.h> /* various networking crud */`
		17	`#include <netinet/in.h>`
		18	`#include <netdb.h>`
		19
		20	`#include <fcall.h>`
		21	`#include <oldfcall.h>`
		22	`#include <u9fs.h>`
		23
		24	`/* #ifndef because can be given in makefile */`
		25	`#ifndef DEFAULTLOG`
		26	`#define DEFAULTLOG "/tmp/u9fs.log"`
		27	`#endif`
		28
65	7u83	29
2	-	30	`char *logfile = DEFAULTLOG;`
		31
		32	`#define S_ISSPECIAL(m) (S_ISCHR(m) \|\| S_ISBLK(m) \|\| S_ISFIFO(m))`
		33
		34	`enum {`
		35	`Tdot = 1,`
		36	`Tdotdot`
		37	`};`
		38
		39	`enum {`
		40	`P9P1,`
		41	`P9P2000`
		42	`};`
		43
		44	`typedef struct User User;`
		45	`struct User {`
		46	`int id;`
		47	`gid_t defaultgid;`
		48	`char *name;`
		49	`char *mem; / group members */`
		50	`int nmem;`
		51	`User *next;`
		52	`};`
		53
		54	`struct Fid {`
		55	`int fid;`
		56	`char *path;`
		57	`struct stat st;`
		58	`User *u;`
		59	`int omode;`
		60	`DIR *dir;`
		61	`int diroffset;`
		62	`int fd;`
		63	`struct dirent *dirent;`
		64	`int direof;`
		65	`Fid *next;`
		66	`Fid *prev;`
		67	`int auth;`
		68	`void *authmagic;`
		69	`};`
		70
		71	`void* emalloc(size_t);`
		72	`void* erealloc(void*, size_t);`
		73	`char* estrdup(char*);`
		74	`char* estrpath(char, char, int);`
		75	`void sysfatal(char*, ...);`
		76	`int okuser(char*);`
		77
		78	`void rversion(Fcall, Fcall);`
		79	`void rauth(Fcall, Fcall);`
		80	`void rattach(Fcall, Fcall);`
		81	`void rflush(Fcall, Fcall);`
		82	`void rclone(Fcall, Fcall);`
		83	`void rwalk(Fcall, Fcall);`
		84	`void ropen(Fcall, Fcall);`
		85	`void rcreate(Fcall, Fcall);`
		86	`void rread(Fcall, Fcall);`
		87	`void rwrite(Fcall, Fcall);`
		88	`void rclunk(Fcall, Fcall);`
		89	`void rstat(Fcall, Fcall);`
		90	`void rwstat(Fcall, Fcall);`
		91	`void rclwalk(Fcall, Fcall);`
		92	`void rremove(Fcall, Fcall);`
		93
		94	`User* uname2user(char*);`
		95	`User* gname2user(char*);`
		96	`User* uid2user(int);`
		97	`User* gid2user(int);`
		98
		99	`Fid* newfid(int, char**);`
		100	`Fid* oldfidex(int, int, char**);`
		101	`Fid* oldfid(int, char**);`
		102	`int fidstat(Fid, char*);`
		103	`void freefid(Fid*);`
		104
		105	`int userchange(User, char*);`
		106	`int userwalk(User, char, char, Qid, char*);`
		107	`int useropen(Fid, int, char*);`
		108	`int usercreate(Fid, char, int, long, char**);`
		109	`int userremove(Fid, char*);`
		110	`int userperm(User, char, int, int);`
		111	`int useringroup(User, User);`
		112
		113	`Qid stat2qid(struct stat*);`
		114
		115	`void getfcallold(int, Fcall*, int);`
		116	`void putfcallold(int, Fcall*);`
		117
		118	`char Eauth[] = "authentication failed";`
		119	`char Ebadfid[] = "fid unknown or out of range";`
		120	`char Ebadoffset[] = "bad offset in directory read";`
		121	`char Ebadusefid[] = "bad use of fid";`
		122	`char Edirchange[] = "wstat can't convert between files and directories";`
		123	`char Eexist[] = "file or directory already exists";`
		124	`char Efidactive[] = "fid already in use";`
		125	`char Enotdir[] = "not a directory";`
		126	`char Enotingroup[] = "not a member of proposed group";`
		127	`char Enotowner[] = "only owner can change group in wstat";`
		128	`char Eperm[] = "permission denied";`
		129	`char Especial0[] = "already attached without access to special files";`
		130	`char Especial1[] = "already attached with access to special files";`
		131	`char Especial[] = "no access to special file";`
		132	`char Etoolarge[] = "i/o count too large";`
		133	`char Eunknowngroup[] = "unknown group";`
		134	`char Eunknownuser[] = "unknown user";`
		135	`char Ewstatbuffer[] = "bogus wstat buffer";`
		136
		137	`ulong msize = IOHDRSZ+8192;`
		138	`uchar* rxbuf;`
		139	`uchar* txbuf;`
		140	`void* databuf;`
		141	`int connected;`
		142	`int devallowed;`
		143	`char* autharg;`
		144	`char* defaultuser;`
		145	`char hostname[256];`
		146	`char remotehostname[256];`
		147	`int chatty9p = 0;`
		148	`int network = 1;`
		149	`int old9p = -1;`
		150	`int authed;`
		151	`User* none;`
		152
		153	`Auth authmethods[] = { / first is default */`
		154	`&authrhosts,`
		155	`&authp9any,`
		156	`&authnone,`
		157	`};`
		158
		159	`Auth *auth;`
		160
65	7u83	161
		162
2	-	163	`/*`
		164	`* frogs: characters not valid in plan9`
		165	`* filenames, keep this list in sync with`
		166	`* /sys/src/9/port/chan.c:1656`
		167	`*/`
		168	`char isfrog[256]={`
		169	`/NUL/ 1, 1, 1, 1, 1, 1, 1, 1,`
		170	`/BKS/ 1, 1, 1, 1, 1, 1, 1, 1,`
		171	`/DLE/ 1, 1, 1, 1, 1, 1, 1, 1,`
		172	`/CAN/ 1, 1, 1, 1, 1, 1, 1, 1,`
70	7u83	173	`['/'] = 1,`
		174	`[0x7f] = 1,`
2	-	175	`};`
		176
65	7u83	177	`int groupchange(User u, User g, char **ep);`
		178
		179
		180
2	-	181	`void`
		182	`getfcallnew(int fd, Fcall *fc, int have)`
		183	`{`
		184	`int len;`
		185
		186	`if(have > BIT32SZ)`
		187	`sysfatal("cannot happen");`
		188
		189	`if(have < BIT32SZ && readn(fd, rxbuf+have, BIT32SZ-have) != BIT32SZ-have)`
		190	`sysfatal("couldn't read message");`
		191
		192	`len = GBIT32(rxbuf);`
		193	`if(len <= BIT32SZ)`
		194	`sysfatal("bogus message");`
		195
		196	`len -= BIT32SZ;`
		197	`if(readn(fd, rxbuf+BIT32SZ, len) != len)`
		198	`sysfatal("short message");`
		199
		200	`if(convM2S(rxbuf, len+BIT32SZ, fc) != len+BIT32SZ)`
		201	`sysfatal("badly sized message type %d", rxbuf[0]);`
		202	`}`
		203
		204	`void`
		205	`getfcallold(int fd, Fcall *fc, int have)`
		206	`{`
		207	`int len, n;`
		208
		209	`if(have > 3)`
		210	`sysfatal("cannot happen");`
		211
		212	`if(have < 3 && readn(fd, rxbuf, 3-have) != 3-have)`
		213	`sysfatal("couldn't read message");`
		214
		215	`len = oldhdrsize(rxbuf[0]);`
		216	`if(len < 3)`
		217	`sysfatal("bad message %d", rxbuf[0]);`
		218	`if(len > 3 && readn(fd, rxbuf+3, len-3) != len-3)`
		219	`sysfatal("couldn't read message");`
		220
		221	`n = iosize(rxbuf);`
		222	`if(readn(fd, rxbuf+len, n) != n)`
		223	`sysfatal("couldn't read message");`
		224	`len += n;`
		225
		226	`if(convM2Sold(rxbuf, len, fc) != len)`
		227	`sysfatal("badly sized message type %d", rxbuf[0]);`
		228	`}`
		229
		230	`void`
		231	`putfcallnew(int wfd, Fcall *tx)`
		232	`{`
		233	`uint n;`
		234
		235	`if((n = convS2M(tx, txbuf, msize)) == 0)`
		236	`sysfatal("couldn't format message type %d", tx->type);`
		237	`if(write(wfd, txbuf, n) != n)`
		238	`sysfatal("couldn't send message");`
		239	`}`
		240
		241	`void`
		242	`putfcallold(int wfd, Fcall *tx)`
		243	`{`
		244	`uint n;`
		245
		246	`if((n = convS2Mold(tx, txbuf, msize)) == 0)`
		247	`sysfatal("couldn't format message type %d", tx->type);`
		248	`if(write(wfd, txbuf, n) != n)`
		249	`sysfatal("couldn't send message");`
		250	`}`
		251
		252	`void`
		253	`getfcall(int fd, Fcall *fc)`
		254	`{`
		255	`if(old9p == 1){`
		256	`getfcallold(fd, fc, 0);`
		257	`return;`
		258	`}`
		259	`if(old9p == 0){`
		260	`getfcallnew(fd, fc, 0);`
		261	`return;`
		262	`}`
		263
		264	`/* auto-detect */`
		265	`if(readn(fd, rxbuf, 3) != 3)`
		266	`sysfatal("couldn't read message");`
		267
		268	`/* is it an old (9P1) message? */`
		269	`if(50 <= rxbuf[0] && rxbuf[0] <= 87 && (rxbuf[0]&1)==0 && GBIT16(rxbuf+1) == 0xFFFF){`
		270	`old9p = 1;`
		271	`getfcallold(fd, fc, 3);`
		272	`return;`
		273	`}`
		274
		275	`getfcallnew(fd, fc, 3);`
		276	`old9p = 0;`
		277	`}`
		278
		279	`void`
		280	`seterror(Fcall f, char error)`
		281	`{`
		282	`f->type = Rerror;`
		283	`f->ename = error ? error : "programmer error";`
		284	`}`
		285
		286	`int`
		287	`isowner(User u, Fid f)`
		288	`{`
		289	`return u->id == f->st.st_uid;`
		290	`}`
		291
		292
		293
		294	`void`
		295	`serve(int rfd, int wfd)`
		296	`{`
		297	`Fcall rx, tx;`
		298
		299	`for(;;){`
		300	`getfcall(rfd, &rx);`
		301
		302	`if(chatty9p)`
		303	`fprint(2, "<- %F\n", &rx);`
		304
		305	`memset(&tx, 0, sizeof tx);`
		306	`tx.type = rx.type+1;`
		307	`tx.tag = rx.tag;`
		308	`switch(rx.type){`
		309	`case Tflush:`
		310	`break;`
		311	`case Tversion:`
		312	`rversion(&rx, &tx);`
		313	`break;`
		314	`case Tauth:`
		315	`rauth(&rx, &tx);`
		316	`break;`
		317	`case Tattach:`
		318	`rattach(&rx, &tx);`
		319	`break;`
		320	`case Twalk:`
		321	`rwalk(&rx, &tx);`
		322	`break;`
		323	`case Tstat:`
		324	`tx.stat = databuf;`
		325	`rstat(&rx, &tx);`
		326	`break;`
		327	`case Twstat:`
		328	`rwstat(&rx, &tx);`
		329	`break;`
		330	`case Topen:`
		331	`ropen(&rx, &tx);`
		332	`break;`
		333	`case Tcreate:`
		334	`rcreate(&rx, &tx);`
		335	`break;`
		336	`case Tread:`
		337	`tx.data = databuf;`
		338	`rread(&rx, &tx);`
		339	`break;`
		340	`case Twrite:`
		341	`rwrite(&rx, &tx);`
		342	`break;`
		343	`case Tclunk:`
		344	`rclunk(&rx, &tx);`
		345	`break;`
		346	`case Tremove:`
		347	`rremove(&rx, &tx);`
		348	`break;`
		349	`default:`
		350	`fprint(2, "unknown message %F\n", &rx);`
		351	`seterror(&tx, "bad message");`
		352	`break;`
		353	`}`
		354
		355	`if(chatty9p)`
		356	`fprint(2, "-> %F\n", &tx);`
		357
		358	`(old9p ? putfcallold : putfcallnew)(wfd, &tx);`
		359	`}`
		360	`}`
		361
		362	`void`
		363	`rversion(Fcall rx, Fcall tx)`
		364	`{`
		365	`if(msize > rx->msize)`
		366	`msize = rx->msize;`
		367	`tx->msize = msize;`
		368	`if(strncmp(rx->version, "9P", 2) != 0)`
		369	`tx->version = "unknown";`
		370	`else`
		371	`tx->version = "9P2000";`
		372	`}`
		373
		374	`void`
		375	`rauth(Fcall rx, Fcall tx)`
		376	`{`
		377	`char *e;`
		378
		379	`if((e = auth->auth(rx, tx)) != nil)`
		380	`seterror(tx, e);`
		381	`}`
		382
		383	`void`
		384	`rattach(Fcall rx, Fcall tx)`
		385	`{`
		386	`char *e;`
		387	`Fid *fid;`
		388	`User *u;`
		389
		390	`if(rx->aname == nil)`
		391	`rx->aname = "";`
		392
		393	`if(strcmp(rx->aname, "device") == 0){`
		394	`if(connected && !devallowed){`
		395	`seterror(tx, Especial0);`
		396	`return;`
		397	`}`
		398	`devallowed = 1;`
		399	`}else{`
		400	`if(connected && devallowed){`
		401	`seterror(tx, Especial1);`
		402	`return;`
		403	`}`
		404	`}`
		405
		406	`if(strcmp(rx->uname, "none") == 0){`
		407	`if(authed == 0){`
		408	`seterror(tx, Eauth);`
		409	`return;`
		410	`}`
		411	`if (none != nil)`
		412	`rx->uname = none->name;`
		413	`} else {`
		414	`if((e = auth->attach(rx, tx)) != nil){`
		415	`seterror(tx, e);`
		416	`return;`
		417	`}`
		418	`authed++;`
		419	`}`
		420
		421	`if((fid = newfid(rx->fid, &e)) == nil){`
		422	`seterror(tx, e);`
		423	`return;`
		424	`}`
		425	`fid->path = estrdup("/");`
		426	`if(fidstat(fid, &e) < 0){`
		427	`seterror(tx, e);`
		428	`freefid(fid);`
		429	`return;`
		430	`}`
		431
		432	`if(defaultuser)`
		433	`rx->uname = defaultuser;`
		434
		435	`if((u = uname2user(rx->uname)) == nil`
		436	`\|\| (!defaultuser && u->id == 0)){`
		437	`/* we don't know anyone named root... */`
		438	`seterror(tx, Eunknownuser);`
		439	`freefid(fid);`
		440	`return;`
		441	`}`
		442
68	7u83	443
2	-	444	`fid->u = u;`
		445	`tx->qid = stat2qid(&fid->st);`
69	7u83	446	`chroot("/srv");`
2	-	447	`return;`
		448	`}`
		449
		450	`void`
		451	`rwalk(Fcall rx, Fcall tx)`
		452	`{`
69	7u83	453
2	-	454	`int i;`
		455	`char path, e;`
		456	`Fid fid, nfid;`
		457
		458	`e = nil;`
		459	`if((fid = oldfid(rx->fid, &e)) == nil){`
		460	`seterror(tx, e);`
		461	`return;`
		462	`}`
		463
		464	`if(fid->omode != -1){`
		465	`seterror(tx, Ebadusefid);`
		466	`return;`
		467	`}`
		468
		469	`if(fidstat(fid, &e) < 0){`
		470	`seterror(tx, e);`
		471	`return;`
		472	`}`
		473
		474	`if(!S_ISDIR(fid->st.st_mode) && rx->nwname){`
		475	`seterror(tx, Enotdir);`
		476	`return;`
		477	`}`
		478
		479	`nfid = nil;`
		480	`if(rx->newfid != rx->fid && (nfid = newfid(rx->newfid, &e)) == nil){`
		481	`seterror(tx, e);`
		482	`return;`
		483	`}`
		484
		485	`path = estrdup(fid->path);`
		486	`e = nil;`
		487	`for(i=0; i<rx->nwname; i++)`
		488	`if(userwalk(fid->u, &path, rx->wname[i], &tx->wqid[i], &e) < 0)`
		489	`break;`
		490
		491	`if(i == rx->nwname){ /* successful clone or walk */`
		492	`tx->nwqid = i;`
		493	`if(nfid){`
		494	`nfid->path = path;`
		495	`nfid->u = fid->u;`
		496	`}else{`
		497	`free(fid->path);`
		498	`fid->path = path;`
		499	`}`
		500	`}else{`
		501	`if(i > 0) /* partial walk? */`
		502	`tx->nwqid = i;`
		503	`else`
		504	`seterror(tx, e);`
		505
		506	`if(nfid) /* clone implicit new fid */`
		507	`freefid(nfid);`
		508	`free(path);`
		509	`}`
		510	`return;`
		511	`}`
		512
		513	`void`
		514	`ropen(Fcall rx, Fcall tx)`
		515	`{`
		516	`char *e;`
		517	`Fid *fid;`
		518
		519	`if((fid = oldfid(rx->fid, &e)) == nil){`
		520	`seterror(tx, e);`
		521	`return;`
		522	`}`
		523
		524	`if(fid->omode != -1){`
		525	`seterror(tx, Ebadusefid);`
		526	`return;`
		527	`}`
		528
		529	`if(fidstat(fid, &e) < 0){`
		530	`seterror(tx, e);`
		531	`return;`
		532	`}`
		533
		534	`if(!devallowed && S_ISSPECIAL(fid->st.st_mode)){`
		535	`seterror(tx, Especial);`
		536	`return;`
		537	`}`
		538
		539	`if(useropen(fid, rx->mode, &e) < 0){`
		540	`seterror(tx, e);`
		541	`return;`
		542	`}`
		543
		544	`tx->iounit = 0;`
		545	`tx->qid = stat2qid(&fid->st);`
		546	`}`
		547
		548	`void`
		549	`rcreate(Fcall rx, Fcall tx)`
		550	`{`
		551	`char *e;`
		552	`Fid *fid;`
		553
		554	`if((fid = oldfid(rx->fid, &e)) == nil){`
		555	`seterror(tx, e);`
		556	`return;`
		557	`}`
		558
		559	`if(fid->omode != -1){`
		560	`seterror(tx, Ebadusefid);`
		561	`return;`
		562	`}`
		563
		564	`if(fidstat(fid, &e) < 0){`
		565	`seterror(tx, e);`
		566	`return;`
		567	`}`
		568
		569	`if(!S_ISDIR(fid->st.st_mode)){`
		570	`seterror(tx, Enotdir);`
		571	`return;`
		572	`}`
		573
		574	`if(usercreate(fid, rx->name, rx->mode, rx->perm, &e) < 0){`
		575	`seterror(tx, e);`
		576	`return;`
		577	`}`
		578
		579	`if(fidstat(fid, &e) < 0){`
		580	`seterror(tx, e);`
		581	`return;`
		582	`}`
		583
		584	`tx->iounit = 0;`
		585	`tx->qid = stat2qid(&fid->st);`
		586	`}`
		587
		588	`uchar`
		589	`modebyte(struct stat *st)`
		590	`{`
		591	`uchar b;`
		592
		593	`b = 0;`
		594
		595	`if(S_ISDIR(st->st_mode))`
		596	`b \|= QTDIR;`
		597
		598	`/* no way to test append-only */`
		599	`/* no real way to test exclusive use, but mark devices as such */`
		600	`if(S_ISSPECIAL(st->st_mode))`
		601	`b \|= QTEXCL;`
		602
		603	`return b;`
		604	`}`
		605
		606	`ulong`
		607	`plan9mode(struct stat *st)`
		608	`{`
		609	`return ((ulong)modebyte(st)<<24) \| (st->st_mode & 0777);`
		610	`}`
		611
		612	`/*`
		613	`* this is for chmod, so don't worry about S_IFDIR`
		614	`*/`
		615	`mode_t`
		616	`unixmode(Dir *d)`
		617	`{`
		618	`return (mode_t)(d->mode&0777);`
		619	`}`
		620
		621	`Qid`
		622	`stat2qid(struct stat *st)`
		623	`{`
		624	`uchar p, ep, *q;`
		625	`Qid qid;`
		626
		627	`/*`
		628	`* For now, ignore the device number.`
		629	`*/`
		630	`qid.path = 0;`
		631	`p = (uchar*)&qid.path;`
		632	`ep = p+sizeof(qid.path);`
		633	`q = p+sizeof(ino_t);`
		634	`if(q > ep){`
		635	`fprint(2, "warning: inode number too big\n");`
		636	`q = ep;`
		637	`}`
		638	`memmove(p, &st->st_ino, q-p);`
		639	`q = q+sizeof(dev_t);`
		640	`if(q > ep){`
		641	`/*`
		642	`* fprint(2, "warning: inode number + device number too big %d+%d\n",`
		643	`* sizeof(ino_t), sizeof(dev_t));`
		644	`*/`
		645	`q = ep - sizeof(dev_t);`
		646	`if(q < p)`
		647	`fprint(2, "warning: device number too big by itself\n");`
		648	`else`
		649	`(dev_t)q ^= st->st_dev;`
		650	`}`
		651
		652	`qid.vers = st->st_mtime ^ (st->st_size << 8);`
		653	`qid.type = modebyte(st);`
		654	`return qid;`
		655	`}`
		656
		657	`char *`
		658	`enfrog(char *src)`
		659	`{`
		660	`char d, dst;`
		661	`uchar *s;`
		662
		663	`d = dst = emalloc(strlen(src)*3 + 1);`
		664	`for (s = (uchar )src; s; s++)`
		665	`if(isfrog[s] \|\| s == '\\')`
		666	`d += sprintf(d, "\\%02x", *s);`
		667	`else`
		668	`d++ = s;`
		669	`*d = 0;`
		670	`return dst;`
		671	`}`
		672
		673	`char *`
		674	`defrog(char *s)`
		675	`{`
		676	`char d, dst, buf[3];`
		677
		678	`d = dst = emalloc(strlen(s) + 1);`
		679	`for(; *s; s++)`
		680	`if(*s == '\\' && strlen(s) >= 3){`
		681	`buf[0] = ++s; / skip \ */`
		682	`buf[1] = *++s;`
		683	`buf[2] = 0;`
		684	`*d++ = strtoul(buf, NULL, 16);`
		685	`} else`
		686	`d++ = s;`
		687	`*d = 0;`
		688	`return dst;`
		689	`}`
		690
		691	`void`
		692	`stat2dir(char path, struct stat st, Dir *d)`
		693	`{`
		694	`User *u;`
		695	`char q, p, *npath;`
		696
		697	`memset(d, 0, sizeof(*d));`
		698	`d->qid = stat2qid(st);`
		699	`d->mode = plan9mode(st);`
		700	`d->atime = st->st_atime;`
		701	`d->mtime = st->st_mtime;`
		702	`d->length = st->st_size;`
		703
		704	`d->uid = (u = uid2user(st->st_uid)) ? u->name : "???";`
		705	`d->gid = (u = gid2user(st->st_gid)) ? u->name : "???";`
		706	`d->muid = "";`
		707
		708	`if((q = strrchr(path, '/')) != nil)`
		709	`d->name = enfrog(q+1);`
		710	`else`
		711	`d->name = enfrog(path);`
		712	`}`
		713
		714	`void`
		715	`rread(Fcall rx, Fcall tx)`
		716	`{`
		717	`char e, path;`
		718	`uchar p, ep;`
		719	`int n;`
		720	`Fid *fid;`
		721	`Dir d;`
		722	`struct stat st;`
		723
		724	`if(rx->count > msize-IOHDRSZ){`
		725	`seterror(tx, Etoolarge);`
		726	`return;`
		727	`}`
		728
		729	`if((fid = oldfidex(rx->fid, -1, &e)) == nil){`
		730	`seterror(tx, e);`
		731	`return;`
		732	`}`
		733
		734	`if (fid->auth) {`
		735	`char *e;`
		736	`e = auth->read(rx, tx);`
		737	`if (e)`
		738	`seterror(tx, e);`
		739	`return;`
		740	`}`
		741
		742	`if(fid->omode == -1 \|\| (fid->omode&3) == OWRITE){`
		743	`seterror(tx, Ebadusefid);`
		744	`return;`
		745	`}`
		746
		747	`if(fid->dir){`
		748	`if(rx->offset != fid->diroffset){`
		749	`if(rx->offset != 0){`
		750	`seterror(tx, Ebadoffset);`
		751	`return;`
		752	`}`
		753	`rewinddir(fid->dir);`
		754	`fid->diroffset = 0;`
		755	`fid->direof = 0;`
		756	`}`
		757	`if(fid->direof){`
		758	`tx->count = 0;`
		759	`return;`
		760	`}`
		761
		762	`p = (uchar*)tx->data;`
		763	`ep = (uchar*)tx->data+rx->count;`
		764	`for(;;){`
		765	`if(p+BIT16SZ >= ep)`
		766	`break;`
		767	`if(fid->dirent == nil) /* one entry cache for when convD2M fails */`
		768	`if((fid->dirent = readdir(fid->dir)) == nil){`
		769	`fid->direof = 1;`
		770	`break;`
		771	`}`
		772	`if(strcmp(fid->dirent->d_name, ".") == 0`
		773	`\|\| strcmp(fid->dirent->d_name, "..") == 0){`
		774	`fid->dirent = nil;`
		775	`continue;`
		776	`}`
		777	`path = estrpath(fid->path, fid->dirent->d_name, 0);`
		778	`memset(&st, 0, sizeof st);`
		779	`if(stat(path, &st) < 0){`
		780	`fprint(2, "dirread: stat(%s) failed: %s\n", path, strerror(errno));`
		781	`fid->dirent = nil;`
		782	`free(path);`
		783	`continue;`
		784	`}`
		785	`free(path);`
		786	`stat2dir(fid->dirent->d_name, &st, &d);`
		787	`if((n=(old9p ? convD2Mold : convD2M)(&d, p, ep-p)) <= BIT16SZ)`
		788	`break;`
		789	`p += n;`
		790	`fid->dirent = nil;`
		791	`}`
		792	`tx->count = p - (uchar*)tx->data;`
		793	`fid->diroffset += tx->count;`
		794	`}else{`
		795	`if((n = pread(fid->fd, tx->data, rx->count, rx->offset)) < 0){`
		796	`seterror(tx, strerror(errno));`
		797	`return;`
		798	`}`
		799	`tx->count = n;`
		800	`}`
		801	`}`
		802
		803	`void`
		804	`rwrite(Fcall rx, Fcall tx)`
		805	`{`
		806	`char *e;`
		807	`Fid *fid;`
		808	`int n;`
		809
		810	`if(rx->count > msize-IOHDRSZ){`
		811	`seterror(tx, Etoolarge);`
		812	`return;`
		813	`}`
		814
		815	`if((fid = oldfidex(rx->fid, -1, &e)) == nil){`
		816	`seterror(tx, e);`
		817	`return;`
		818	`}`
		819
		820	`if (fid->auth) {`
		821	`char *e;`
		822	`e = auth->write(rx, tx);`
		823	`if (e)`
		824	`seterror(tx, e);`
		825	`return;`
		826	`}`
		827
		828	`if(fid->omode == -1 \|\| (fid->omode&3) == OREAD \|\| (fid->omode&3) == OEXEC){`
		829	`seterror(tx, Ebadusefid);`
		830	`return;`
		831	`}`
		832
		833	`if((n = pwrite(fid->fd, rx->data, rx->count, rx->offset)) < 0){`
		834	`seterror(tx, strerror(errno));`
		835	`return;`
		836	`}`
		837	`tx->count = n;`
		838	`}`
		839
		840	`void`
		841	`rclunk(Fcall rx, Fcall tx)`
		842	`{`
		843	`char *e;`
		844	`Fid *fid;`
		845
		846	`if((fid = oldfidex(rx->fid, -1, &e)) == nil){`
		847	`seterror(tx, e);`
		848	`return;`
		849	`}`
		850	`if (fid->auth) {`
		851	`if (auth->clunk) {`
		852	`e = (*auth->clunk)(rx, tx);`
		853	`if (e) {`
		854	`seterror(tx, e);`
		855	`return;`
		856	`}`
		857	`}`
		858	`}`
		859	`else if(fid->omode != -1 && fid->omode&ORCLOSE)`
		860	`remove(fid->path);`
		861	`freefid(fid);`
		862	`}`
		863
		864	`void`
		865	`rremove(Fcall rx, Fcall tx)`
		866	`{`
		867	`char *e;`
		868	`Fid *fid;`
		869
		870	`if((fid = oldfid(rx->fid, &e)) == nil){`
		871	`seterror(tx, e);`
		872	`return;`
		873	`}`
		874	`if(userremove(fid, &e) < 0)`
		875	`seterror(tx, e);`
		876	`freefid(fid);`
		877	`}`
		878
		879	`void`
		880	`rstat(Fcall rx, Fcall tx)`
		881	`{`
		882	`char *e;`
		883	`Fid *fid;`
		884	`Dir d;`
		885
		886	`if((fid = oldfid(rx->fid, &e)) == nil){`
		887	`seterror(tx, e);`
		888	`return;`
		889	`}`
		890
		891	`if(fidstat(fid, &e) < 0){`
		892	`seterror(tx, e);`
		893	`return;`
		894	`}`
		895
		896	`stat2dir(fid->path, &fid->st, &d);`
		897	`if((tx->nstat=(old9p ? convD2Mold : convD2M)(&d, tx->stat, msize)) <= BIT16SZ)`
		898	`seterror(tx, "convD2M fails");`
		899	`}`
		900
		901	`void`
		902	`rwstat(Fcall rx, Fcall tx)`
		903	`{`
		904	`char *e;`
		905	`char p, old, new, dir;`
		906	`gid_t gid;`
		907	`Dir d;`
		908	`Fid *fid;`
		909
		910	`if((fid = oldfid(rx->fid, &e)) == nil){`
		911	`seterror(tx, e);`
		912	`return;`
		913	`}`
		914
		915	`/*`
		916	`* wstat is supposed to be atomic.`
		917	`* we check all the things we can before trying anything.`
		918	`* still, if we are told to truncate a file and rename it and only`
		919	`* one works, we're screwed. in such cases we leave things`
		920	`* half broken and return an error. it's hardly perfect.`
		921	`*/`
		922	`if((old9p ? convM2Dold : convM2D)(rx->stat, rx->nstat, &d, (char*)rx->stat) <= BIT16SZ){`
		923	`seterror(tx, Ewstatbuffer);`
		924	`return;`
		925	`}`
		926
		927	`if(fidstat(fid, &e) < 0){`
		928	`seterror(tx, e);`
		929	`return;`
		930	`}`
		931
		932	`/*`
		933	`* The casting is necessary because d.mode is ulong and might,`
		934	`* on some systems, be 64 bits. We only want to compare the`
		935	`* bottom 32 bits, since that's all that gets sent in the protocol.`
		936	`*`
		937	`* Same situation for d.mtime and d.length (although that last check`
		938	`* is admittedly superfluous, given the current lack of 128-bit machines).`
		939	`*/`
		940	`gid = (gid_t)-1;`
		941	`if(d.gid[0] != '\0'){`
		942	`User *g;`
		943
		944	`g = gname2user(d.gid);`
		945	`if(g == nil){`
		946	`seterror(tx, Eunknowngroup);`
		947	`return;`
		948	`}`
		949	`gid = (gid_t)g->id;`
		950
		951	`if(groupchange(fid->u, gid2user(gid), &e) < 0){`
		952	`seterror(tx, e);`
		953	`return;`
		954	`}`
		955	`}`
		956
		957	`if((u32int)d.mode != (u32int)~0 && (((d.mode&DMDIR)!=0) ^ (S_ISDIR(fid->st.st_mode)!=0))){`
		958	`seterror(tx, Edirchange);`
		959	`return;`
		960	`}`
		961
		962	`if(strcmp(fid->path, "/") == 0){`
		963	`seterror(tx, "no wstat of root");`
		964	`return;`
		965	`}`
		966
		967	`/*`
		968	`* try things in increasing order of harm to the file.`
		969	`* mtime should come after truncate so that if you`
		970	`* do both the mtime actually takes effect, but i'd rather`
		971	`* leave truncate until last.`
		972	`* (see above comment about atomicity).`
		973	`*/`
		974	`if((u32int)d.mode != (u32int)~0 && chmod(fid->path, unixmode(&d)) < 0){`
		975	`if(chatty9p)`
		976	`fprint(2, "chmod(%s, 0%luo) failed\n", fid->path, unixmode(&d));`
		977	`seterror(tx, strerror(errno));`
		978	`return;`
		979	`}`
		980
		981	`if((u32int)d.mtime != (u32int)~0){`
		982	`struct utimbuf t;`
		983
		984	`t.actime = 0;`
		985	`t.modtime = d.mtime;`
		986	`if(utime(fid->path, &t) < 0){`
		987	`if(chatty9p)`
		988	`fprint(2, "utime(%s) failed\n", fid->path);`
		989	`seterror(tx, strerror(errno));`
		990	`return;`
		991	`}`
		992	`}`
		993
		994	`if(gid != (gid_t)-1 && gid != fid->st.st_gid){`
		995	`if(chown(fid->path, (uid_t)-1, gid) < 0){`
		996	`if(chatty9p)`
		997	`fprint(2, "chgrp(%s, %d) failed\n", fid->path, gid);`
		998	`seterror(tx, strerror(errno));`
		999	`return;`
		1000	`}`
		1001	`}`
		1002
		1003	`if(d.name[0]){`
		1004	`old = fid->path;`
		1005	`dir = estrdup(fid->path);`
		1006	`if((p = strrchr(dir, '/')) > dir)`
		1007	`*p = '\0';`
		1008	`else{`
		1009	`seterror(tx, "whoops: can't happen in u9fs");`
		1010	`return;`
		1011	`}`
		1012	`new = estrpath(dir, d.name, 1);`
		1013	`if(strcmp(old, new) != 0 && rename(old, new) < 0){`
		1014	`if(chatty9p)`
		1015	`fprint(2, "rename(%s, %s) failed\n", old, new);`
		1016	`seterror(tx, strerror(errno));`
		1017	`free(new);`
		1018	`free(dir);`
		1019	`return;`
		1020	`}`
		1021	`fid->path = new;`
		1022	`free(old);`
		1023	`free(dir);`
		1024	`}`
		1025
		1026	`if((u64int)d.length != (u64int)~0 && truncate(fid->path, d.length) < 0){`
		1027	`fprint(2, "truncate(%s, %lld) failed\n", fid->path, d.length);`
		1028	`seterror(tx, strerror(errno));`
		1029	`return;`
		1030	`}`
		1031	`}`
		1032
		1033	`/*`
		1034	`* we keep a table by numeric id. by name lookups happen infrequently`
		1035	`* while by-number lookups happen once for every directory entry read`
		1036	`* and every stat request.`
		1037	`*/`
		1038	`User *utab[64];`
		1039	`User *gtab[64];`
		1040
		1041	`User*`
		1042	`adduser(struct passwd *p)`
		1043	`{`
		1044	`User *u;`
		1045
		1046	`u = emalloc(sizeof(*u));`
		1047	`u->id = p->pw_uid;`
		1048	`u->name = estrdup(p->pw_name);`
		1049	`u->next = utab[p->pw_uid%nelem(utab)];`
		1050	`u->defaultgid = p->pw_gid;`
		1051	`utab[p->pw_uid%nelem(utab)] = u;`
		1052	`return u;`
		1053	`}`
		1054
		1055	`int`
		1056	`useringroup(User u, User g)`
		1057	`{`
		1058	`int i;`
		1059
		1060	`for(i=0; i<g->nmem; i++)`
		1061	`if(strcmp(g->mem[i], u->name) == 0)`
		1062	`return 1;`
		1063
		1064	`/*`
		1065	`* Hack around common Unix problem that everyone has`
		1066	`* default group "user" but /etc/group lists no members.`
		1067	`*/`
		1068	`if(u->defaultgid == g->id)`
		1069	`return 1;`
		1070	`return 0;`
		1071	`}`
		1072
		1073	`User*`
		1074	`addgroup(struct group *g)`
		1075	`{`
		1076	`User *u;`
		1077	`char **p;`
		1078	`int n;`
		1079
		1080	`u = emalloc(sizeof(*u));`
		1081	`n = 0;`
		1082	`for(p=g->gr_mem; *p; p++)`
		1083	`n++;`
		1084	`u->mem = emalloc(sizeof(u->mem[0])*n);`
		1085	`n = 0;`
		1086	`for(p=g->gr_mem; *p; p++)`
		1087	`u->mem[n++] = estrdup(*p);`
		1088	`u->nmem = n;`
		1089	`u->id = g->gr_gid;`
		1090	`u->name = estrdup(g->gr_name);`
		1091	`u->next = gtab[g->gr_gid%nelem(gtab)];`
		1092	`gtab[g->gr_gid%nelem(gtab)] = u;`
		1093	`return u;`
		1094	`}`
		1095
		1096	`User*`
		1097	`uname2user(char *name)`
		1098	`{`
		1099	`int i;`
		1100	`User *u;`
		1101	`struct passwd *p;`
		1102
		1103	`for(i=0; i<nelem(utab); i++)`
		1104	`for(u=utab[i]; u; u=u->next)`
		1105	`if(strcmp(u->name, name) == 0)`
		1106	`return u;`
		1107
		1108	`if((p = getpwnam(name)) == nil)`
		1109	`return nil;`
		1110	`return adduser(p);`
		1111	`}`
		1112
		1113	`User*`
		1114	`uid2user(int id)`
		1115	`{`
		1116	`User *u;`
		1117	`struct passwd *p;`
		1118
		1119	`for(u=utab[id%nelem(utab)]; u; u=u->next)`
		1120	`if(u->id == id)`
		1121	`return u;`
		1122
		1123	`if((p = getpwuid(id)) == nil)`
		1124	`return nil;`
		1125	`return adduser(p);`
		1126	`}`
		1127
		1128	`User*`
		1129	`gname2user(char *name)`
		1130	`{`
		1131	`int i;`
		1132	`User *u;`
		1133	`struct group *g;`
		1134
		1135	`for(i=0; i<nelem(gtab); i++)`
		1136	`for(u=gtab[i]; u; u=u->next)`
		1137	`if(strcmp(u->name, name) == 0)`
		1138	`return u;`
		1139
		1140	`if((g = getgrnam(name)) == nil)`
		1141	`return nil;`
		1142	`return addgroup(g);`
		1143	`}`
		1144
		1145	`User*`
		1146	`gid2user(int id)`
		1147	`{`
		1148	`User *u;`
		1149	`struct group *g;`
		1150
		1151	`for(u=gtab[id%nelem(gtab)]; u; u=u->next)`
		1152	`if(u->id == id)`
		1153	`return u;`
		1154
		1155	`if((g = getgrgid(id)) == nil)`
		1156	`return nil;`
		1157	`return addgroup(g);`
		1158	`}`
		1159
		1160	`void`
		1161	`sysfatal(char *fmt, ...)`
		1162	`{`
		1163	`char buf[1024];`
		1164	`va_list va, temp;`
		1165
		1166	`va_start(va, fmt);`
		1167	`va_copy(temp, va);`
		1168	`doprint(buf, buf+sizeof buf, fmt, &temp);`
		1169	`va_end(temp);`
		1170	`va_end(va);`
		1171	`fprint(2, "u9fs: %s\n", buf);`
		1172	`fprint(2, "last unix error: %s\n", strerror(errno));`
		1173	`exit(1);`
		1174	`}`
		1175
		1176	`void*`
		1177	`emalloc(size_t n)`
		1178	`{`
		1179	`void *p;`
		1180
		1181	`if(n == 0)`
		1182	`n = 1;`
		1183	`p = malloc(n);`
		1184	`if(p == 0)`
		1185	`sysfatal("malloc(%ld) fails", (long)n);`
		1186	`memset(p, 0, n);`
		1187	`return p;`
		1188	`}`
		1189
		1190	`void*`
		1191	`erealloc(void *p, size_t n)`
		1192	`{`
		1193	`if(p == 0)`
		1194	`p = malloc(n);`
		1195	`else`
		1196	`p = realloc(p, n);`
		1197	`if(p == 0)`
		1198	`sysfatal("realloc(..., %ld) fails", (long)n);`
		1199	`return p;`
		1200	`}`
		1201
		1202	`char*`
		1203	`estrdup(char *p)`
		1204	`{`
		1205	`p = strdup(p);`
		1206	`if(p == 0)`
		1207	`sysfatal("strdup(%.20s) fails", p);`
		1208	`return p;`
		1209	`}`
		1210
		1211	`char*`
		1212	`estrpath(char p, char q, int frog)`
		1213	`{`
		1214	`char r, s;`
		1215
		1216	`if(strcmp(q, "..") == 0){`
		1217	`r = estrdup(p);`
		1218	`if((s = strrchr(r, '/')) && s > r)`
		1219	`*s = '\0';`
		1220	`else if(s == r)`
		1221	`s[1] = '\0';`
		1222	`return r;`
		1223	`}`
		1224
		1225	`if(frog)`
		1226	`q = defrog(q);`
		1227	`else`
		1228	`q = strdup(q);`
		1229	`r = emalloc(strlen(p)+1+strlen(q)+1);`
		1230	`strcpy(r, p);`
		1231	`if(r[0]=='\0' \|\| r[strlen(r)-1] != '/')`
		1232	`strcat(r, "/");`
		1233	`strcat(r, q);`
		1234	`free(q);`
		1235	`return r;`
		1236	`}`
		1237
		1238	`Fid *fidtab[1];`
		1239
		1240	`Fid*`
		1241	`lookupfid(int fid)`
		1242	`{`
		1243	`Fid *f;`
		1244
		1245	`for(f=fidtab[fid%nelem(fidtab)]; f; f=f->next)`
		1246	`if(f->fid == fid)`
		1247	`return f;`
		1248	`return nil;`
		1249	`}`
		1250
		1251	`Fid*`
		1252	`newfid(int fid, char **ep)`
		1253	`{`
		1254	`Fid *f;`
		1255
		1256	`if(lookupfid(fid) != nil){`
		1257	`*ep = Efidactive;`
		1258	`return nil;`
		1259	`}`
		1260
		1261	`f = emalloc(sizeof(*f));`
		1262	`f->next = fidtab[fid%nelem(fidtab)];`
		1263	`if(f->next)`
		1264	`f->next->prev = f;`
		1265	`fidtab[fid%nelem(fidtab)] = f;`
		1266	`f->fid = fid;`
		1267	`f->fd = -1;`
		1268	`f->omode = -1;`
		1269	`return f;`
		1270	`}`
		1271
		1272	`Fid*`
		1273	`newauthfid(int fid, void magic, char *ep)`
		1274	`{`
		1275	`Fid *af;`
		1276	`af = newfid(fid, ep);`
		1277	`if (af == nil)`
		1278	`return nil;`
		1279	`af->auth = 1;`
		1280	`af->authmagic = magic;`
		1281	`return af;`
		1282	`}`
		1283
		1284	`Fid*`
		1285	`oldfidex(int fid, int auth, char **ep)`
		1286	`{`
		1287	`Fid *f;`
		1288
		1289	`if((f = lookupfid(fid)) == nil){`
		1290	`*ep = Ebadfid;`
		1291	`return nil;`
		1292	`}`
		1293
		1294	`if (auth != -1 && f->auth != auth) {`
		1295	`*ep = Ebadfid;`
		1296	`return nil;`
		1297	`}`
		1298
		1299	`if (!f->auth) {`
		1300	`if(userchange(f->u, ep) < 0)`
		1301	`return nil;`
		1302	`}`
		1303
		1304	`return f;`
		1305	`}`
		1306
		1307	`Fid*`
		1308	`oldfid(int fid, char **ep)`
		1309	`{`
		1310	`return oldfidex(fid, 0, ep);`
		1311	`}`
		1312
		1313	`Fid*`
		1314	`oldauthfid(int fid, void magic, char ep)`
		1315	`{`
		1316	`Fid *af;`
		1317	`af = oldfidex(fid, 1, ep);`
		1318	`if (af == nil)`
		1319	`return nil;`
		1320	`*magic = af->authmagic;`
		1321	`return af;`
		1322	`}`
		1323
		1324	`void`
		1325	`freefid(Fid *f)`
		1326	`{`
		1327	`if(f->prev)`
		1328	`f->prev->next = f->next;`
		1329	`else`
		1330	`fidtab[f->fid%nelem(fidtab)] = f->next;`
		1331	`if(f->next)`
		1332	`f->next->prev = f->prev;`
		1333	`if(f->dir)`
		1334	`closedir(f->dir);`
		1335	`if(f->fd)`
		1336	`close(f->fd);`
		1337	`free(f->path);`
		1338	`free(f);`
		1339	`}`
		1340
		1341	`int`
		1342	`fidstat(Fid fid, char *ep)`
		1343	`{`
		1344	`if(stat(fid->path, &fid->st) < 0){`
		1345	`fprint(2, "fidstat(%s) failed\n", fid->path);`
		1346	`if(ep)`
		1347	`*ep = strerror(errno);`
		1348	`return -1;`
		1349	`}`
		1350	`if(S_ISDIR(fid->st.st_mode))`
		1351	`fid->st.st_size = 0;`
		1352	`return 0;`
		1353	`}`
		1354
		1355	`int`
		1356	`userchange(User u, char *ep)`
		1357	`{`
		1358	`if(defaultuser)`
		1359	`return 0;`
		1360
		1361	`if(setreuid(0, 0) < 0){`
		1362	`fprint(2, "setreuid(0, 0) failed\n");`
		1363	`*ep = "cannot setuid back to root";`
		1364	`return -1;`
		1365	`}`
		1366
		1367	`/*`
		1368	`* Initgroups does not appear to be SUSV standard.`
		1369	`* But it exists on SGI and on Linux, which makes me`
		1370	`* think it's standard enough. We have to do something`
		1371	`* like this, and the closest other function I can find is`
		1372	`* setgroups (which initgroups eventually calls).`
		1373	`* Setgroups is the same as far as standardization though,`
		1374	`* so we're stuck using a non-SUSV call. Sigh.`
		1375	`*/`
		1376	`if(initgroups(u->name, u->defaultgid) < 0)`
		1377	`fprint(2, "initgroups(%s) failed: %s\n", u->name, strerror(errno));`
		1378
		1379	`if(setreuid(-1, u->id) < 0){`
		1380	`fprint(2, "setreuid(-1, %s) failed\n", u->name);`
		1381	`*ep = strerror(errno);`
		1382	`return -1;`
		1383	`}`
		1384
		1385	`return 0;`
		1386	`}`
		1387
		1388	`/*`
		1389	`* We do our own checking here, then switch to root temporarily`
		1390	`* to set our gid. In a perfect world, you'd be allowed to set your`
		1391	`* egid to any of the supplemental groups of your euid, but this`
		1392	`* is not the case on Linux 2.2.14 (and perhaps others).`
		1393	`*`
		1394	`* This is a race, of course, but it's a race against processes`
		1395	`* that can edit the group lists. If you can do that, you can`
		1396	`* change your own group without our help.`
		1397	`*/`
		1398	`int`
		1399	`groupchange(User u, User g, char **ep)`
		1400	`{`
		1401	`if(g == nil)`
		1402	`return -1;`
		1403	`if(!useringroup(u, g)){`
		1404	`if(chatty9p)`
		1405	`fprint(2, "%s not in group %s\n", u->name, g->name);`
		1406	`*ep = Enotingroup;`
		1407	`return -1;`
		1408	`}`
		1409
		1410	`setreuid(0,0);`
		1411	`if(setregid(-1, g->id) < 0){`
		1412	`fprint(2, "setegid(%s/%d) failed in groupchange\n", g->name, g->id);`
		1413	`*ep = strerror(errno);`
		1414	`return -1;`
		1415	`}`
		1416	`if(userchange(u, ep) < 0)`
		1417	`return -1;`
		1418
		1419	`return 0;`
		1420	`}`
		1421
		1422
		1423	`/*`
		1424	`* An attempt to enforce permissions by looking at the`
		1425	`* file system. Separation of checking permission and`
		1426	`* actually performing the action is a terrible idea, of`
		1427	`* course, so we use setreuid for most of the permission`
		1428	`* enforcement. This is here only so we can give errors`
		1429	`* on open(ORCLOSE) in some cases.`
		1430	`*/`
		1431	`int`
		1432	`userperm(User u, char path, int type, int need)`
		1433	`{`
		1434	`char p, q;`
		1435	`int i, have;`
		1436	`struct stat st;`
		1437	`User *g;`
		1438
		1439	`switch(type){`
		1440	`default:`
		1441	`fprint(2, "bad type %d in userperm\n", type);`
		1442	`return -1;`
		1443	`case Tdot:`
		1444	`if(stat(path, &st) < 0){`
		1445	`fprint(2, "userperm: stat(%s) failed\n", path);`
		1446	`return -1;`
		1447	`}`
		1448	`break;`
		1449	`case Tdotdot:`
		1450	`p = estrdup(path);`
		1451	`if((q = strrchr(p, '/'))==nil){`
		1452	`fprint(2, "userperm(%s, ..): bad path\n", p);`
		1453	`free(p);`
		1454	`return -1;`
		1455	`}`
		1456	`if(q > p)`
		1457	`*q = '\0';`
		1458	`else`
		1459	`*(q+1) = '\0';`
		1460	`if(stat(p, &st) < 0){`
		1461	`fprint(2, "userperm: stat(%s) (dotdot of %s) failed\n",`
		1462	`p, path);`
		1463	`free(p);`
		1464	`return -1;`
		1465	`}`
		1466	`free(p);`
		1467	`break;`
		1468	`}`
		1469
		1470	`if(u == none){`
		1471	`fprint(2, "userperm: none wants %d in 0%luo\n", need, st.st_mode);`
		1472	`have = st.st_mode&7;`
		1473	`if((have&need)==need)`
		1474	`return 0;`
		1475	`return -1;`
		1476	`}`
		1477	`have = st.st_mode&7;`
		1478	`if((uid_t)u->id == st.st_uid)`
		1479	`have \|= (st.st_mode>>6)&7;`
		1480	`if((have&need)==need)`
		1481	`return 0;`
		1482	`if(((have\|((st.st_mode>>3)&7))&need) != need) /* group won't help */`
		1483	`return -1;`
		1484	`g = gid2user(st.st_gid);`
		1485	`for(i=0; i<g->nmem; i++){`
		1486	`if(strcmp(g->mem[i], u->name) == 0){`
		1487	`have \|= (st.st_mode>>3)&7;`
		1488	`break;`
		1489	`}`
		1490	`}`
		1491	`if((have&need)==need)`
		1492	`return 0;`
		1493	`return -1;`
		1494	`}`
		1495
		1496	`int`
		1497	`userwalk(User u, char path, char elem, Qid qid, char *ep)`
		1498	`{`
		1499	`char *npath;`
		1500	`struct stat st;`
		1501
		1502	`npath = estrpath(*path, elem, 1);`
		1503	`if(stat(npath, &st) < 0){`
		1504	`free(npath);`
		1505	`*ep = strerror(errno);`
		1506	`return -1;`
		1507	`}`
		1508	`*qid = stat2qid(&st);`
		1509	`free(*path);`
		1510	`*path = npath;`
		1511	`return 0;`
		1512	`}`
		1513
		1514	`int`
		1515	`useropen(Fid fid, int omode, char *ep)`
		1516	`{`
		1517	`int a, o;`
		1518
		1519	`/*`
		1520	`* Check this anyway, to try to head off problems later.`
		1521	`*/`
		1522	`if((omode&ORCLOSE) && userperm(fid->u, fid->path, Tdotdot, W_OK) < 0){`
		1523	`*ep = Eperm;`
		1524	`return -1;`
		1525	`}`
		1526
		1527	`switch(omode&3){`
		1528	`default:`
		1529	`*ep = "programmer error";`
		1530	`return -1;`
		1531	`case OREAD:`
		1532	`a = R_OK;`
		1533	`o = O_RDONLY;`
		1534	`break;`
		1535	`case ORDWR:`
		1536	`a = R_OK\|W_OK;`
		1537	`o = O_RDWR;`
		1538	`break;`
		1539	`case OWRITE:`
		1540	`a = W_OK;`
		1541	`o = O_WRONLY;`
		1542	`break;`
		1543	`case OEXEC:`
		1544	`a = X_OK;`
		1545	`o = O_RDONLY;`
		1546	`break;`
		1547	`}`
		1548	`if(omode & OTRUNC){`
		1549	`a \|= W_OK;`
		1550	`o \|= O_TRUNC;`
		1551	`}`
		1552
		1553	`if(S_ISDIR(fid->st.st_mode)){`
		1554	`if(a != R_OK){`
		1555	`fprint(2, "attempt by %s to open dir %d\n", fid->u->name, omode);`
		1556	`*ep = Eperm;`
		1557	`return -1;`
		1558	`}`
		1559	`if((fid->dir = opendir(fid->path)) == nil){`
		1560	`*ep = strerror(errno);`
		1561	`return -1;`
		1562	`}`
		1563	`}else{`
		1564	`/*`
		1565	`* This is wrong because access used the real uid`
		1566	`* and not the effective uid. Let the open sort it out.`
		1567	`*`
		1568	`if(access(fid->path, a) < 0){`
		1569	`*ep = strerror(errno);`
		1570	`return -1;`
		1571	`}`
		1572	`*`
		1573	`*/`
		1574	`if((fid->fd = open(fid->path, o)) < 0){`
		1575	`*ep = strerror(errno);`
		1576	`return -1;`
		1577	`}`
		1578	`}`
		1579	`fid->omode = omode;`
		1580	`return 0;`
		1581	`}`
		1582
		1583	`int`
		1584	`usercreate(Fid fid, char elem, int omode, long perm, char **ep)`
		1585	`{`
		1586	`int o, m;`
		1587	`char opath, npath;`
		1588	`struct stat st, parent;`
		1589
		1590	`if(stat(fid->path, &parent) < 0){`
		1591	`*ep = strerror(errno);`
		1592	`return -1;`
		1593	`}`
		1594
		1595	`/*`
		1596	`* Change group so that created file has expected group`
		1597	`* by Plan 9 semantics. If that fails, might as well go`
		1598	`* with the user's default group.`
		1599	`*/`
		1600	`if(groupchange(fid->u, gid2user(parent.st_gid), ep) < 0`
		1601	`&& groupchange(fid->u, gid2user(fid->u->defaultgid), ep) < 0)`
		1602	`return -1;`
		1603
		1604	`m = (perm & DMDIR) ? 0777 : 0666;`
		1605	`perm = perm & (~m \| (fid->st.st_mode & m));`
		1606
		1607	`npath = estrpath(fid->path, elem, 1);`
		1608	`if(perm & DMDIR){`
		1609	`if((omode&~ORCLOSE) != OREAD){`
		1610	`*ep = Eperm;`
		1611	`free(npath);`
		1612	`return -1;`
		1613	`}`
		1614	`if(stat(npath, &st) >= 0 \|\| errno != ENOENT){`
		1615	`*ep = Eexist;`
		1616	`free(npath);`
		1617	`return -1;`
		1618	`}`
		1619	`/* race */`
		1620	`if(mkdir(npath, (perm\|0400)&0777) < 0){`
		1621	`*ep = strerror(errno);`
		1622	`free(npath);`
		1623	`return -1;`
		1624	`}`
		1625	`if((fid->dir = opendir(npath)) == nil){`
		1626	`*ep = strerror(errno);`
		1627	`remove(npath); /* race */`
		1628	`free(npath);`
		1629	`return -1;`
		1630	`}`
		1631	`}else{`
		1632	`o = O_CREAT\|O_EXCL;`
		1633	`switch(omode&3){`
		1634	`default:`
		1635	`*ep = "programmer error";`
		1636	`return -1;`
		1637	`case OREAD:`
		1638	`case OEXEC:`
		1639	`o \|= O_RDONLY;`
		1640	`break;`
		1641	`case ORDWR:`
		1642	`o \|= O_RDWR;`
		1643	`break;`
		1644	`case OWRITE:`
		1645	`o \|= O_WRONLY;`
		1646	`break;`
		1647	`}`
		1648	`if(omode & OTRUNC)`
		1649	`o \|= O_TRUNC;`
		1650	`if((fid->fd = open(npath, o, perm&0777)) < 0){`
		1651	`if(chatty9p)`
		1652	`fprint(2, "create(%s, 0x%x, 0%o) failed\n", npath, o, perm&0777);`
		1653	`*ep = strerror(errno);`
		1654	`free(npath);`
		1655	`return -1;`
		1656	`}`
		1657	`}`
		1658
		1659	`opath = fid->path;`
		1660	`fid->path = npath;`
		1661	`if(fidstat(fid, ep) < 0){`
		1662	`fprint(2, "stat after create on %s failed\n", npath);`
		1663	`remove(npath); /* race */`
		1664	`free(npath);`
		1665	`fid->path = opath;`
		1666	`if(fid->fd >= 0){`
		1667	`close(fid->fd);`
		1668	`fid->fd = -1;`
		1669	`}else{`
		1670	`closedir(fid->dir);`
		1671	`fid->dir = nil;`
		1672	`}`
		1673	`return -1;`
		1674	`}`
		1675	`fid->omode = omode;`
		1676	`free(opath);`
		1677	`return 0;`
		1678	`}`
		1679
		1680	`int`
		1681	`userremove(Fid fid, char *ep)`
		1682	`{`
		1683	`if(remove(fid->path) < 0){`
		1684	`*ep = strerror(errno);`
		1685	`return -1;`
		1686	`}`
		1687	`return 0;`
		1688	`}`
		1689
		1690	`void`
		1691	`usage(void)`
		1692	`{`
		1693	`fprint(2, "usage: u9fs [-Dnz] [-a authmethod] [-m msize] [-u user] [root]\n");`
		1694	`exit(1);`
		1695	`}`
		1696
		1697	`int`
		1698	`main(int argc, char **argv)`
		1699	`{`
		1700	`char *authtype;`
		1701	`int i;`
		1702	`int fd;`
		1703	`int logflag;`
		1704
		1705	`auth = authmethods[0];`
		1706	`logflag = O_WRONLY\|O_APPEND\|O_CREAT;`
		1707	`ARGBEGIN{`
		1708	`case 'D':`
		1709	`chatty9p = 1;`
		1710	`break;`
		1711	`case 'a':`
		1712	`authtype = EARGF(usage());`
		1713	`auth = nil;`
		1714	`for(i=0; i<nelem(authmethods); i++)`
		1715	`if(strcmp(authmethods[i]->name, authtype)==0)`
		1716	`auth = authmethods[i];`
		1717	`if(auth == nil)`
		1718	`sysfatal("unknown auth type '%s'", authtype);`
		1719	`break;`
		1720	`case 'A':`
		1721	`autharg = EARGF(usage());`
		1722	`break;`
		1723	`case 'l':`
		1724	`logfile = EARGF(usage());`
		1725	`break;`
		1726	`case 'm':`
		1727	`msize = strtol(EARGF(usage()), 0, 0);`
		1728	`break;`
		1729	`case 'n':`
		1730	`network = 0;`
		1731	`break;`
		1732	`case 'u':`
		1733	`defaultuser = EARGF(usage());`
		1734	`break;`
		1735	`case 'z':`
		1736	`logflag \|= O_TRUNC;`
		1737	`}ARGEND`
		1738
		1739	`if(argc > 1)`
		1740	`usage();`
		1741
		1742	`fd = open(logfile, logflag, 0666);`
		1743	`if(fd < 0)`
		1744	`sysfatal("cannot open log '%s'", logfile);`
		1745
		1746	`if(dup2(fd, 2) < 0)`
		1747	`sysfatal("cannot dup fd onto stderr");`
		1748	`fprint(2, "u9fs\nkill %d\n", (int)getpid());`
		1749
		1750	`fmtinstall('F', fcallconv);`
		1751	`fmtinstall('D', dirconv);`
		1752	`fmtinstall('M', dirmodeconv);`
		1753
		1754	`rxbuf = emalloc(msize);`
		1755	`txbuf = emalloc(msize);`
		1756	`databuf = emalloc(msize);`
		1757
		1758	`if(auth->init)`
		1759	`auth->init();`
		1760
		1761	`if(network)`
		1762	`getremotehostname(remotehostname, sizeof remotehostname);`
		1763
		1764	`if(gethostname(hostname, sizeof hostname) < 0)`
		1765	`strcpy(hostname, "gnot");`
		1766
		1767	`umask(0);`
		1768
		1769	`if(argc == 1)`
		1770	`if(chroot(argv[0]) < 0)`
		1771	`sysfatal("chroot '%s' failed", argv[0]);`
		1772
		1773	`none = uname2user("none");`
		1774	`if(none == nil)`
		1775	`none = uname2user("nobody");`
		1776
		1777	`serve(0, 1);`
		1778	`return 0;`
		1779	`}`

Subversion Repositories planix.SVN

(root)/os/branches/feature_unix/sys/src/cmd/unix/u9fs/u9fs.c – Rev 70