Based on f813180f2fc1d682dd097e4a05ef4d15000204ad Mon Sep 17 00:00:00 2001 From: Roman Kollar Date: Mon, 29 Oct 2012 17:52:52 +0100 Subject: [PATCH] Add .history file locking - shared readers, exclusive writer Originally reported at Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=648592 Patch by Vojtech Vitek (V-Teq) Additional changes reflecting: https://bugzilla.redhat.com/show_bug.cgi?id=879371 Changes by Fridolin Pokorny --- sh.c | 102 +++++++++++++++++++++++++++++++++++++-------------- sh.decls.h | 4 +- sh.dol.c | 2 - sh.err.c | 16 ++++++++ sh.h | 18 +++++++++ sh.hist.c | 122 ++++++++++++++++++++++++++++++------------------------------- sh.lex.c | 8 ++-- sh.sem.c | 2 - 8 files changed, 178 insertions(+), 96 deletions(-) --- sh.c +++ sh.c 2019-08-22 12:07:57.729632215 +0000 @@ -138,6 +138,7 @@ struct saved_state { int cantell; struct Bin B; int justpr; + int close_unit; }; static int srccat (Char *, Char *); @@ -1359,7 +1360,7 @@ main(int argc, char **argv) /* * Source history before .login so that it is available in .login */ - loadhist(NULL, 0); + loadhist(NULL, HIST_FILE_RDLCK); #ifndef LOGINFIRST if (loginsh) (void) srccat(varval(STRhome), STRsldotlogin); @@ -1508,7 +1509,7 @@ static int srccat(Char *cp, Char *dp) { if (cp[0] == '/' && cp[1] == '\0') - return srcfile(short2str(dp), (mflag ? 0 : 1), 0, NULL); + return srcfile(short2str(dp), (mflag ? 0 : HIST_ONLY), 0, NULL); else { Char *ep; char *ptr; @@ -1524,7 +1525,7 @@ srccat(Char *cp, Char *dp) cleanup_push(ep, xfree); ptr = short2str(ep); - rv = srcfile(ptr, (mflag ? 0 : 1), 0, NULL); + rv = srcfile(ptr, (mflag ? 0 : HIST_ONLY), 0, NULL); cleanup_until(ep); return rv; } @@ -1538,20 +1539,49 @@ static int #else int #endif /*WINNT_NATIVE*/ -srcfile(const char *f, int onlyown, int flag, Char **av) +srcfile(const char *f, int onlyown, int flg, Char **av) { - int unit; + int *unit; - if ((unit = xopen(f, O_RDONLY|O_LARGEFILE)) == -1) - return 0; - cleanup_push(&unit, open_cleanup); - unit = dmove(unit, -1); - cleanup_ignore(&unit); - cleanup_until(&unit); - - (void) close_on_exec(unit, 1); - srcunit(unit, onlyown, flag, av); - return 1; + unit = xmalloc(sizeof(*unit)); + cleanup_push(unit, xfree); + *unit = xopen(f, O_LARGEFILE | + ((flg & HIST_FILE_WRLCK) ? (O_CREAT|O_RDWR) : O_RDONLY), 0600); + if (*unit == -1) + return 0; /* Error. */ + + cleanup_push(unit, open_cleanup); + *unit = dmove(*unit, -1); + (void) close_on_exec(*unit, 1); + + if (flg & (HIST_FILE_WRLCK | HIST_FILE_RDLCK)) { + struct flock fl; + + fl.l_type = (flg & HIST_FILE_WRLCK) ? F_WRLCK : F_RDLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 0; + + cleanup_push(unit, fcntl_cleanup); + if (fcntl(*unit, F_SETLKW, &fl) == -1) + cleanup_ignore(unit); + } + + srcunit(*unit, onlyown, flg, av); + + /* Unlock the unit, if we don't want to leave it locked (or open). */ + if ((flg & (HIST_FILE_WRLCK | HIST_FILE_RDLCK)) && + (!(flg & HIST_FILE_LOCK) || !(flg & HIST_FILE_OPEN))) + cleanup_until(unit); /* fcntl_cleanup */ + + /* Close the unit, if we don't want to leave it open. */ + if (!(flg & HIST_FILE_OPEN)) { + cleanup_until(unit); /* open_cleanup */ + cleanup_until(unit); /* xfree */ + return -1; /* Not error but invalid file descriptor. */ + } + + return *unit; /* File descriptor (fd > FSAFE). */ } @@ -1560,7 +1590,7 @@ srcfile(const char *f, int onlyown, int * fd. */ static void -st_save(struct saved_state *st, int unit, int hflg, Char **al, Char **av) +st_save(struct saved_state *st, int unit, int flg, Char **al, Char **av) { st->insource = insource; st->SHIN = SHIN; @@ -1609,10 +1639,14 @@ st_save(struct saved_state *st, int unit st->onelflg = onelflg; st->enterhist = enterhist; st->justpr = justpr; - if (hflg) + if (flg & (HIST_ONLY | HIST_MERGE)) st->HIST = HIST; else st->HIST = '\0'; + if (flg & HIST_FILE_OPEN) + st->close_unit = 0; + else + st->close_unit = 1; st->cantell = cantell; cpybin(st->B, B); @@ -1651,7 +1685,7 @@ st_save(struct saved_state *st, int unit evalp = 0; alvec = al; alvecp = 0; - enterhist = hflg; + enterhist = flg & (HIST_ONLY | HIST_MERGE); if (enterhist) HIST = '\0'; insource = 1; @@ -1684,7 +1718,8 @@ st_restore(void *xst) } cpybin(B, st->B); - xclose(SHIN); + if (st->close_unit) + xclose(SHIN); insource = st->insource; SHIN = st->SHIN; @@ -1720,7 +1755,7 @@ st_restore(void *xst) * we don't chance it. This occurs on ".cshrc"s and the like. */ static void -srcunit(int unit, int onlyown, int hflg, Char **av) +srcunit(int unit, int onlyown, int flg, Char **av) { struct saved_state st; @@ -1746,7 +1781,7 @@ srcunit(int unit, int onlyown, int hflg, } /* Save the current state and move us to a new state */ - st_save(&st, unit, hflg, NULL, av); + st_save(&st, unit, flg, NULL, av); /* * Now if we are allowing commands to be interrupted, we let ourselves be @@ -2088,7 +2123,7 @@ process(int catch) * elsewhere... */ if (enterhist || (catch && intty && !whyles && !tellwhat && !arun)) - savehist(¶ml, enterhist > 1); + savehist(¶ml, enterhist > 1 ? HIST_MERGE : 0); if (Expand && seterr) Expand = 0; @@ -2175,21 +2210,28 @@ process(int catch) void dosource(Char **t, struct command *c) { + (void) dosource_flg(t, c, 0); +} + +int +dosource_flg(Char **t, struct command *c, int flg) +{ Char *f; - int hflg = 0; char *file; + int fd; + int newflg = 0; USE(c); t++; if (*t && eq(*t, STRmh)) { if (*++t == NULL) stderror(ERR_NAME | ERR_HFLAG); - hflg++; + newflg |= HIST_ONLY; } else if (*t && eq(*t, STRmm)) { if (*++t == NULL) stderror(ERR_NAME | ERR_MFLAG); - hflg = 2; + newflg |= HIST_MERGE; } f = globone(*t++, G_ERROR); @@ -2198,9 +2240,15 @@ dosource(Char **t, struct command *c) xfree(f); t = glob_all_or_error(t); cleanup_push(t, blk_cleanup); - if ((!srcfile(file, 0, hflg, t)) && (!hflg) && (!bequiet)) + fd = srcfile(file, 0, (flg | newflg), t); + if ((!fd) && (!newflg) && (!bequiet)) stderror(ERR_SYSTEM, file, strerror(errno)); - cleanup_until(file); + /* We need to preserve fd and it's cleaning routines on the top of the + * cleaning stack. Don't call cleanup_until() but clean it manually. */ + cleanup_ignore(file); + xfree(file); + + return fd; /* Valid/invalid file descriptor (>FSAVE, -1). Zero on error. */ } /* --- sh.decls.h +++ sh.decls.h 2019-08-22 12:07:57.729632215 +0000 @@ -37,6 +37,7 @@ */ extern Char *gethdir (const Char *); extern void dosource (Char **, struct command *); +extern int dosource_flg (Char **, struct command *, int); extern void exitstat (void); extern void goodbye (Char **, struct command *); extern void importpath (Char *); @@ -98,6 +99,7 @@ extern void cleanup_until_mark(void); extern size_t cleanup_push_mark(void); extern void cleanup_pop_mark(size_t); extern void open_cleanup(void *); +extern void fcntl_cleanup(void *); extern void opendir_cleanup(void *); extern void sigint_cleanup(void *); extern void sigprocmask_cleanup(void *); @@ -220,7 +222,7 @@ extern struct Hist *enthist (int, str extern void savehist (struct wordent *, int); extern char *fmthist (int, ptr_t); extern void rechist (Char *, int); -extern void loadhist (Char *, int); +extern int loadhist (Char *, int); extern void displayHistStats(const char *); extern void sethistory (int); --- sh.dol.c +++ sh.dol.c 2019-08-22 12:07:57.729632215 +0000 @@ -1117,6 +1117,6 @@ again: *obp = 0; tmp = short2str(obuf); (void) xwrite(0, tmp, strlen (tmp)); - (void) lseek(0, (off_t) 0, L_SET); + (void) lseek(0, (off_t) 0, SEEK_SET); cleanup_until(&inheredoc); } --- sh.err.c +++ sh.err.c 2019-08-22 12:07:57.733632140 +0000 @@ -511,6 +511,22 @@ open_cleanup(void *xptr) } void +fcntl_cleanup(void *xptr) +{ + int *ptr; + struct flock fl; + + ptr = xptr; + + fl.l_type = F_UNLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 0; + + fcntl(*ptr, F_SETLK, &fl); +} + +void opendir_cleanup(void *xdir) { DIR *dir; --- sh.h +++ sh.h 2019-08-22 12:07:57.733632140 +0000 @@ -49,6 +49,24 @@ # include #endif +#include +#include + +/* + * History flags. + */ +#define HIST_ONLY 0x001 +#define HIST_SAVE 0x002 +#define HIST_LOAD 0x004 +#define HIST_REV 0x008 +#define HIST_CLEAR 0x010 +#define HIST_MERGE 0x020 +#define HIST_TIME 0x040 +#define HIST_FILE_WRLCK 0x080 /* Write lock */ +#define HIST_FILE_RDLCK 0x100 /* Read lock */ +#define HIST_FILE_OPEN 0x200 /* Leave file open */ +#define HIST_FILE_LOCK 0x400 /* Leave file locked */ + #if !defined(HAVE_STDINT_H) && !defined(HAVE_INTTYPES_H) && !defined(WINNT_NATIVE) typedef unsigned long intptr_t; #endif --- sh.hist.c +++ sh.hist.c 2019-08-22 12:24:42.518825681 +0000 @@ -32,6 +32,8 @@ #include "sh.h" #include /* for rename(2), grr. */ #include +#include +#include #include "tc.h" #include "dotlock.h" @@ -42,14 +44,6 @@ Char HistLit = 0; static int heq (const struct wordent *, const struct wordent *); static void hfree (struct Hist *); -#define HIST_ONLY 0x01 -#define HIST_SAVE 0x02 -#define HIST_LOAD 0x04 -#define HIST_REV 0x08 -#define HIST_CLEAR 0x10 -#define HIST_MERGE 0x20 -#define HIST_TIME 0x40 - /* * C shell */ @@ -141,13 +135,13 @@ discardExcess(int hlen) void savehist( struct wordent *sp, - int mflg) /* true if -m (merge) specified */ + int flg) /* true if -m (merge) specified */ { /* throw away null lines */ if (sp && sp->next->word[0] == '\n') return; if (sp) - (void) enthist(++eventno, sp, 1, mflg, histlen); + (void) enthist(++eventno, sp, 1, flg, histlen); discardExcess(histlen); } @@ -919,7 +913,7 @@ enthist( int event, /* newly incremented global eventno */ struct wordent *lp, int docopy, - int mflg, /* true if merge requested */ + int flg, /* true if merge requested */ int hlen) /* -1 if unknown */ { struct Hist *p = NULL, *pp = &Histlist, *pTime = NULL; @@ -939,7 +933,7 @@ enthist( Htime = p->Htime; /* If we are merging, and the old entry is at the place we want * to insert the new entry, then remember the place. */ - if (mflg && Htime != 0 && p->Hprev->Htime >= Htime) + if ((flg & HIST_MERGE) && Htime != 0 && p->Hprev->Htime >= Htime) pTime = p->Hprev; if (!fastMergeErase) renumberHist(p); /* Reset Href of subsequent entries */ @@ -998,7 +992,7 @@ enthist( /* The head of history list is the default insertion point. If merging, advance insertion point, in pp, according to Htime. */ /* XXX -- In histdup=all, Htime values can be non-monotonic. */ - if (mflg) { /* merge according to np->Htime */ + if (flg & HIST_MERGE) { /* merge according to np->Htime */ pp = mergeInsertionPoint(np, pTime); for (p = pp->Hnext; p && p->Htime == np->Htime; pp = p, p = p->Hnext) { if (heq(&p->Hlex, &np->Hlex)) { @@ -1037,11 +1031,11 @@ hfree(struct Hist *hp) } PG_STATIC void -phist(struct Hist *hp, int hflg) +phist(struct Hist *hp, int flg) { if (hp->Href < 0) return; - if (hflg & HIST_ONLY) { + if (flg & HIST_ONLY) { int old_output_raw; /* @@ -1053,7 +1047,7 @@ phist(struct Hist *hp, int hflg) old_output_raw = output_raw; output_raw = 1; cleanup_push(&old_output_raw, output_raw_restore); - if (hflg & HIST_TIME) + if (flg & HIST_TIME) /* * Make file entry with history time in format: * "+NNNNNNNNNN" (10 digits, left padded with ascii '0') @@ -1084,7 +1078,7 @@ phist(struct Hist *hp, int hflg) } PG_STATIC void -dophist(int n, int hflg) +dophist(int n, int flg) { struct Hist *hp; if (setintr) { @@ -1093,7 +1087,7 @@ dophist(int n, int hflg) pintr_push_enable(&old_pintr_disabled); cleanup_until(&old_pintr_disabled); } - if ((hflg & HIST_REV) == 0) { + if (!(flg & HIST_REV)) { /* Since the history list is stored most recent first, non-reversing * print needs to print (backwards) up the list. */ if ((unsigned)n >= histCount) @@ -1107,10 +1101,10 @@ dophist(int n, int hflg) if (hp == NULL) return; /* nothing to print */ for (; hp != &Histlist; hp = hp->Hprev) - phist(hp, hflg); + phist(hp, flg); } else { for (hp = Histlist.Hnext; n-- > 0 && hp != NULL; hp = hp->Hnext) - phist(hp, hflg); + phist(hp, flg); } } @@ -1118,7 +1112,7 @@ dophist(int n, int hflg) void dohist(Char **vp, struct command *c) { - int n, hflg = 0; + int n, flg = 0; USE(c); if (getn(varval(STRhistory)) == 0) @@ -1129,40 +1123,40 @@ dohist(Char **vp, struct command *c) while (*++vp2) switch (*vp2) { case 'c': - hflg |= HIST_CLEAR; + flg |= HIST_CLEAR; break; case 'h': - hflg |= HIST_ONLY; + flg |= HIST_ONLY; break; case 'r': - hflg |= HIST_REV; + flg |= HIST_REV; break; case 'S': - hflg |= HIST_SAVE; + flg |= HIST_SAVE; break; case 'L': - hflg |= HIST_LOAD; + flg |= HIST_LOAD; break; case 'M': - hflg |= HIST_MERGE; + flg |= HIST_MERGE; break; case 'T': - hflg |= HIST_TIME; + flg |= HIST_TIME; break; default: stderror(ERR_HISTUS, "chrSLMT"); break; } } - if (hflg & HIST_CLEAR) { + if (flg & HIST_CLEAR) { struct Hist *np, *hp; for (hp = &Histlist; (np = hp->Hnext) != NULL;) hremove(np), hfree(np); } - if (hflg & (HIST_LOAD | HIST_MERGE)) - loadhist(*vp, (hflg & HIST_MERGE) ? 1 : 0); - else if (hflg & HIST_SAVE) + if (flg & (HIST_LOAD | HIST_MERGE)) + loadhist(*vp, (flg | HIST_FILE_RDLCK)); + else if (flg & HIST_SAVE) rechist(*vp, 1); else { if (*vp) @@ -1170,7 +1164,7 @@ dohist(Char **vp, struct command *c) else { n = getn(varval(STRhistory)); } - dophist(n, hflg); + dophist(n, flg); } } @@ -1218,10 +1212,9 @@ dotlock_cleanup(void* lockpath) void rechist(Char *fname, int ref) { - Char *snum, *rs; - int fp, ftmp, oldidfds, phup_disabled_tmp; + Char *snum; + int fd = -1, ftmp, oldidfds, phup_disabled_tmp; struct varent *shist; - char path[MAXPATHLEN]; struct stat st; static Char *dumphist[] = {STRhistory, STRmhT, 0, 0}; @@ -1294,35 +1287,37 @@ rechist(Char *fname, int ref) cleanup_push(lockpath, dotlock_cleanup); #endif } - loadhist(fname, 1); + /* Read .history file, leave it's fd open for writing. */ + fd = loadhist(fname, HIST_MERGE|HIST_FILE_WRLCK|HIST_FILE_OPEN|HIST_FILE_LOCK); + if (fd > 0) { + /* Truncate the .history file. */ + (void) ftruncate(fd, 0); + (void) lseek(fd, (off_t) 0, SEEK_SET); + } } } - rs = randsuf(); - xsnprintf(path, sizeof(path), "%S.%S", fname, rs); - xfree(rs); - - fp = xcreat(path, 0600); - if (fp == -1) { - didfds = oldidfds; - cleanup_until(fname); - phup_disabled = phup_disabled_tmp; - return; + if (fd <= 0) { + /* Open .history file for writing (if not open yet). */ + fd = xopen(short2str(fname), O_LARGEFILE|O_CREAT|O_WRONLY|O_TRUNC, 0600); + if (fd != -1) + cleanup_push(&fd, open_cleanup); } /* Try to preserve ownership and permissions of the original history file */ #ifndef WINNT_NATIVE if (stat(short2str(fname), &st) != -1) { - TCSH_IGNORE(fchown(fp, st.st_uid, st.st_gid)); - TCSH_IGNORE(fchmod(fp, st.st_mode)); + TCSH_IGNORE(fchown(fd, st.st_uid, st.st_gid)); + TCSH_IGNORE(fchmod(fd, st.st_mode)); } #else UNREFERENCED_PARAMETER(st); #endif - ftmp = SHOUT; - SHOUT = fp; - dumphist[2] = snum; - dohist(dumphist, NULL); - xclose(fp); - SHOUT = ftmp; + if (fd != -1) { + ftmp = SHOUT; + SHOUT = fd; + dumphist[2] = snum; + dohist(dumphist, NULL); + SHOUT = ftmp; + } didfds = oldidfds; #ifndef WINNT_NATIVE (void)rename(path, short2str(fname)); @@ -1335,11 +1330,12 @@ rechist(Char *fname, int ref) /* This is the entry point for loading history data from a file. */ -void -loadhist(Char *fname, int mflg) +int +loadhist(Char *fname, int flg) { static Char *loadhist_cmd[] = {STRsource, NULL, NULL, NULL}; - loadhist_cmd[1] = mflg ? STRmm : STRmh; + int fd; + loadhist_cmd[1] = (flg & HIST_MERGE) ? STRmm : STRmh; if (fname != NULL) loadhist_cmd[2] = fname; @@ -1348,17 +1344,19 @@ loadhist(Char *fname, int mflg) else loadhist_cmd[2] = STRtildothist; - dosource(loadhist_cmd, NULL); + fd = dosource_flg(loadhist_cmd, NULL, flg); - /* During history merging (enthist sees mflg set), we disable management of - * Hnum and Href (because fastMergeErase is true). So now reset all the + /* During history merging (enthist sees merge flag), we disable management + * of Hnum and Href (because fastMergeErase is true). So now reset all the * values based on the final ordering of the history list. */ - if (mflg) { + if (flg & HIST_MERGE) { int n = eventno; struct Hist *hp = &Histlist; while ((hp = hp->Hnext)) hp->Hnum = hp->Href = n--; } + + return fd; /* Valid/invalid file descriptor (>FSAVE, -1). Zero on error. */ } void --- sh.lex.c +++ sh.lex.c 2019-08-22 12:07:57.733632140 +0000 @@ -1608,7 +1608,7 @@ wide_read(int fildes, Char *buf, size_t /* Throwing away possible partial multibyte characters on error if the stream is not seekable */ err = errno; - lseek(fildes, -(off_t)partial, L_INCR); + lseek(fildes, -(off_t)partial, SEEK_CUR); errno = err; return res != 0 ? res : r; } @@ -1623,7 +1623,7 @@ bgetc(void) if (cantell) { if (fseekp < fbobp || fseekp > feobp) { fbobp = feobp = fseekp; - (void) lseek(SHIN, fseekp, L_SET); + (void) lseek(SHIN, fseekp, SEEK_SET); } if (fseekp == feobp) { #ifdef WIDE_STRINGS @@ -1827,7 +1827,7 @@ btell(struct Ain *l) void btoeof(void) { - (void) lseek(SHIN, (off_t) 0, L_XTND); + (void) lseek(SHIN, (off_t) 0, SEEK_END); aret = TCSH_F_SEEK; fseekp = feobp; alvec = NULL; @@ -1845,7 +1845,7 @@ settell(void) cantell = 0; if (arginp || onelflg || intty) return; - if ((x = lseek(SHIN, (off_t) 0, L_INCR)) == -1) + if ((x = lseek(SHIN, (off_t) 0, SEEK_CUR)) == -1) return; fbuf = xcalloc(2, sizeof(Char **)); fblocks = 1; --- sh.sem.c +++ sh.sem.c 2019-08-22 12:07:57.733632140 +0000 @@ -905,7 +905,7 @@ doio(struct command *t, int *pipein, int fd = xopen(tmp, O_WRONLY|O_APPEND|O_LARGEFILE); #else /* !O_APPEND */ fd = xopen(tmp, O_WRONLY|O_LARGEFILE); - (void) lseek(fd, (off_t) 0, L_XTND); + (void) lseek(fd, (off_t) 0, SEEK_END); #endif /* O_APPEND */ } else