diff options
| -rw-r--r-- | shell/msh.c | 180 |
1 files changed, 85 insertions, 95 deletions
diff --git a/shell/msh.c b/shell/msh.c index 99b0394..ee54ef2 100644 --- a/shell/msh.c +++ b/shell/msh.c @@ -86,7 +86,7 @@ static char *itoa(int n) # include "busybox.h" /* for applet_names */ #endif -/*#define MSHDEBUG 1*/ +//#define MSHDEBUG 4 #ifdef MSHDEBUG int mshdbg = MSHDEBUG; @@ -244,11 +244,6 @@ static const char *const T_CMD_NAMES[] = { }; #endif -/* - * actions determining the environment of a process - */ -#define FEXEC 1 /* execute without forking */ - #define AREASIZE (90000) /* @@ -402,8 +397,6 @@ struct var { static int yyparse(void); -static int execute(struct op *t, int *pin, int *pout, int act); - /* -------- io.h -------- */ /* io buffer */ @@ -495,7 +488,8 @@ static char **getwords(struct wdblock *wb); /* -------- misc stuff -------- */ -static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp); +static int forkexec(struct op *t, int *pin, int *pout, int no_fork, char **wp); +static int execute(struct op *t, int *pin, int *pout, int no_fork); static int iosetup(struct ioword *iop, int pipein, int pipeout); static void brkset(struct brkcon *bc); static int dolabel(struct op *t); @@ -564,10 +558,13 @@ static const char *const signame[] = { }; +typedef int (*builtin_func_ptr)(struct op *); + struct builtincmd { const char *name; - int (*builtinfunc)(struct op *t); + builtin_func_ptr builtinfunc; }; + static const struct builtincmd builtincmds[] = { { "." , dodot }, { ":" , dolabel }, @@ -1373,7 +1370,7 @@ static void onecommand(void) if (!FLAG['n']) { DBGPRINTF(("ONECOMMAND: calling execute, t=outtree=%p\n", outtree)); - execute(outtree, NOPIPE, NOPIPE, 0); + execute(outtree, NOPIPE, NOPIPE, /* no_fork: */ 0); } if (!interactive && intr) { @@ -2450,7 +2447,7 @@ static struct op *findcase(struct op *t, const char *w) * execute tree */ -static int execute(struct op *t, int *pin, int *pout, int act) +static int execute(struct op *t, int *pin, int *pout, int no_fork) { struct op *t1; volatile int i, rv, a; @@ -2495,17 +2492,17 @@ static int execute(struct op *t, int *pin, int *pout, int act) outtree = outtree_save; if (t->left) - rv = execute(t->left, pin, pout, 0); + rv = execute(t->left, pin, pout, /* no_fork: */ 0); if (t->right) - rv = execute(t->right, pin, pout, 0); + rv = execute(t->right, pin, pout, /* no_fork: */ 0); break; case TPAREN: - rv = execute(t->left, pin, pout, 0); + rv = execute(t->left, pin, pout, /* no_fork: */ 0); break; case TCOM: - rv = forkexec(t, pin, pout, act, wp); + rv = forkexec(t, pin, pout, no_fork, wp); break; case TPIPE: @@ -2517,14 +2514,14 @@ static int execute(struct op *t, int *pin, int *pout, int act) break; pv[0] = remap(pv[0]); pv[1] = remap(pv[1]); - (void) execute(t->left, pin, pv, 0); - rv = execute(t->right, pv, pout, 0); + (void) execute(t->left, pin, pv, /* no_fork: */ 0); + rv = execute(t->right, pv, pout, /* no_fork: */ 0); } break; case TLIST: - (void) execute(t->left, pin, pout, 0); - rv = execute(t->right, pin, pout, 0); + (void) execute(t->left, pin, pout, /* no_fork: */ 0); + rv = execute(t->right, pin, pout, /* no_fork: */ 0); break; case TASYNC: @@ -2544,7 +2541,7 @@ static int execute(struct op *t, int *pin, int *pout, int act) close(0); xopen(bb_dev_null, O_RDONLY); } - _exit(execute(t->left, pin, pout, FEXEC)); + _exit(execute(t->left, pin, pout, /* no_fork: */ 1)); } interactive = hinteractive; if (i != -1) { @@ -2562,10 +2559,10 @@ static int execute(struct op *t, int *pin, int *pout, int act) case TOR: case TAND: - rv = execute(t->left, pin, pout, 0); + rv = execute(t->left, pin, pout, /* no_fork: */ 0); t1 = t->right; if (t1 != NULL && (rv == 0) == (t->type == TAND)) - rv = execute(t1, pin, pout, 0); + rv = execute(t1, pin, pout, /* no_fork: */ 0); break; case TFOR: @@ -2585,7 +2582,7 @@ static int execute(struct op *t, int *pin, int *pout, int act) brkset(&bc); for (t1 = t->left; i-- && *wp != NULL;) { setval(vp, *wp++); - rv = execute(t1, pin, pout, 0); + rv = execute(t1, pin, pout, /* no_fork: */ 0); } brklist = brklist->nextlev; break; @@ -2597,17 +2594,17 @@ static int execute(struct op *t, int *pin, int *pout, int act) goto broken; brkset(&bc); t1 = t->left; - while ((execute(t1, pin, pout, 0) == 0) == (t->type == TWHILE)) - rv = execute(t->right, pin, pout, 0); + while ((execute(t1, pin, pout, /* no_fork: */ 0) == 0) == (t->type == TWHILE)) + rv = execute(t->right, pin, pout, /* no_fork: */ 0); brklist = brklist->nextlev; break; case TIF: case TELIF: if (t->right != NULL) { - rv = !execute(t->left, pin, pout, 0) ? - execute(t->right->left, pin, pout, 0) : - execute(t->right->right, pin, pout, 0); + rv = !execute(t->left, pin, pout, /* no_fork: */ 0) ? + execute(t->right->left, pin, pout, /* no_fork: */ 0) : + execute(t->right->right, pin, pout, /* no_fork: */ 0); } break; @@ -2623,7 +2620,7 @@ static int execute(struct op *t, int *pin, int *pout, int act) t1 = findcase(t->left, cp); if (t1 != NULL) { DBGPRINTF7(("EXECUTE: TCASE, calling execute(t=%p, t1=%p)...\n", t, t1)); - rv = execute(t1, pin, pout, 0); + rv = execute(t1, pin, pout, /* no_fork: */ 0); DBGPRINTF7(("EXECUTE: TCASE, back from execute(t=%p, t1=%p)...\n", t, t1)); } break; @@ -2641,7 +2638,7 @@ static int execute(struct op *t, int *pin, int *pout, int act) if (rv >= 0) { t1 = t->left; if (t1) { - rv = execute(t1, pin, pout, 0); + rv = execute(t1, pin, pout, /* no_fork: */ 0); } } break; @@ -2669,8 +2666,6 @@ static int execute(struct op *t, int *pin, int *pout, int act) return rv; } -typedef int (*builtin_func_ptr)(struct op *); - static builtin_func_ptr inbuilt(const char *s) { const struct builtincmd *bp; @@ -2681,17 +2676,17 @@ static builtin_func_ptr inbuilt(const char *s) return NULL; } -static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) +static int forkexec(struct op *t, int *pin, int *pout, int no_fork, char **wp) { pid_t newpid; int i; builtin_func_ptr bltin = NULL; - int f; - const char *cp = NULL; + const char *bltin_name = NULL; + const char *cp; struct ioword **iopp; int resetsig; char **owp; - int forked = 0; + int forked; int *hpin = pin; int *hpout = pout; @@ -2712,11 +2707,10 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) (void) &owp; #endif - DBGPRINTF(("FORKEXEC: t=%p, pin %p, pout %p, act %d\n", t, pin, - pout, act)); + DBGPRINTF(("FORKEXEC: t=%p, pin %p, pout %p, no_fork %d\n", t, pin, + pout, no_fork)); DBGPRINTF7(("FORKEXEC: t->words is %s\n", - ((t->words == NULL) ? "NULL" : t->words[0]))); - + ((t->words == NULL) ? "NULL" : t->words[0]))); owp = wp; resetsig = 0; if (t->type == TCOM) { @@ -2725,32 +2719,36 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) cp = *wp; /* strip all initial assignments */ - /* not correct wrt PATH=yyy command etc */ + /* FIXME: not correct wrt PATH=yyy command etc */ if (FLAG['x']) { DBGPRINTF9(("FORKEXEC: echo'ing, cp=%p, wp=%p, owp=%p\n", cp, wp, owp)); echo(cp ? wp : owp); } - if (cp == NULL && t->ioact == NULL) { - while ((cp = *owp++) != NULL && assign(cp, COPYV)) - continue; - DBGPRINTF(("FORKEXEC: returning setstatus()\n")); - return setstatus(0); - } - if (cp != NULL) { + if (cp == NULL) { + if (t->ioact == NULL) { + while ((cp = *owp++) != NULL && assign(cp, COPYV)) + continue; + DBGPRINTF(("FORKEXEC: returning setstatus(0)\n")); + return setstatus(0); + } + } else { /* cp != NULL */ + bltin_name = cp; bltin = inbuilt(cp); } } + forked = 0; t->words = wp; - f = act; - - DBGPRINTF(("FORKEXEC: bltin %p, f&FEXEC 0x%x, owp %p\n", bltin, - f & FEXEC, owp)); - - if (!bltin && (f & FEXEC) == 0) { - /* Save values in case the child process alters them */ + DBGPRINTF(("FORKEXEC: bltin %p, no_fork %d, owp %p\n", bltin, + no_fork, owp)); + /* Don't fork if it is a lone builtin (not in pipe) + * OR we are told to _not_ fork */ + if ((!bltin || pin || pout) /* not lone bltin AND */ + && !no_fork /* not told to avoid fork */ + ) { + /* Save values in case child alters them after vfork */ hpin = pin; hpout = pout; hwp = *wp; @@ -2760,9 +2758,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) hexecflg = execflg; DBGPRINTF3(("FORKEXEC: calling vfork()...\n")); - newpid = vfork(); - if (newpid == -1) { DBGPRINTF(("FORKEXEC: ERROR, cannot vfork()!\n")); return -1; @@ -2783,8 +2779,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) } /* Child */ - DBGPRINTF(("FORKEXEC: child process, bltin=%p\n", bltin)); - + DBGPRINTF(("FORKEXEC: child process, bltin=%p (%s)\n", bltin, bltin_name)); if (interactive) { signal(SIGINT, SIG_IGN); signal(SIGQUIT, SIG_IGN); @@ -2802,20 +2797,6 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) if (!bltin) export(lookup(cp)); -#if 1 - /* How to fix it: - * explicitly pass pin[0] and pout[1] to builtins - * instead of making them rely on fd 0/1, - * and do not xmove_fd(pin[0]/pout[1]) below if bltin != NULL. - */ - if ((pin || pout) && bltin && bltin != doexec) { - err("piping to/from shell builtins not yet done"); - if (forked) - _exit(-1); - return -1; - } -#endif - if (pin) { xmove_fd(pin[0], 0); if (pin[1] != 0) @@ -2830,33 +2811,36 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) iopp = t->ioact; if (iopp) { if (bltin && bltin != doexec) { - prs(cp); + prs(bltin_name); err(": cannot redirect shell command"); if (forked) _exit(-1); return -1; } - while (*iopp) + while (*iopp) { if (iosetup(*iopp++, pin != NULL, pout != NULL)) { /* system-detected error */ if (forked) _exit(-1); return -1; } + } } if (bltin) { + if (forked || pin || pout) { + /* Builtin in pipe: disallowed */ + /* TODO: allow "exec"? */ + prs(bltin_name); + err(": cannot run builtin as part of pipe"); + if (forked) + _exit(-1); + return -1; + } i = setstatus(bltin(t)); if (forked) _exit(i); DBGPRINTF(("FORKEXEC: returning i=%d\n", i)); -/* Builtins in pipes ("ls /dev/null | cd"): - * here "cd" (which is not a child) will return to main msh, - * and we will read from ls's output as if it is our next command! - * Result: "/dev/null: cannot execute" - * and then we reach EOF on stdin and exit. - * See above for possible way to fix this. - */ return i; } @@ -2869,7 +2853,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) } if (t->type == TPAREN) - _exit(execute(t->left, NOPIPE, NOPIPE, FEXEC)); + _exit(execute(t->left, NOPIPE, NOPIPE, /* no_fork: */ 1)); if (wp[0] == NULL) _exit(0); @@ -2880,7 +2864,7 @@ static int forkexec(struct op *t, int *pin, int *pout, int act, char **wp) if (!execflg) trap[0] = NULL; - DBGPRINTF(("FORKEXEC: calling leave(), pid=%d\n", newpid)); + DBGPRINTF(("FORKEXEC: calling leave(), pid=%d\n", getpid())); leave(); /* NOTREACHED */ @@ -2927,6 +2911,7 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout) iop->io_flag = IOCLOSE; iop->io_flag &= ~(IOREAD | IOWRITE); } + switch (iop->io_flag) { case IOREAD: u = open(cp, O_RDONLY); @@ -2944,6 +2929,8 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout) lseek(u, (long) 0, SEEK_END); break; } + /* fall through to creation if >>file doesn't exist */ + case IOWRITE: u = creat(cp, 0666); break; @@ -2956,6 +2943,7 @@ static int iosetup(struct ioword *iop, int pipein, int pipeout) close(iop->io_unit); return 0; } + if (u < 0) { prs(cp); prs(": cannot "); @@ -3148,7 +3136,7 @@ static int run(struct ioarg *argp, int (*f) (struct ioarg *)) yynerrs = 0; failpt = rt; if (setjmp(failpt) == 0 && yyparse() == 0) - rv = execute(outtree, NOPIPE, NOPIPE, 0); + rv = execute(outtree, NOPIPE, NOPIPE, /* no_fork: */ 0); quitenv(); } else { DBGPRINTF(("RUN: error from newenv()!\n")); @@ -3267,20 +3255,21 @@ static int dologin(struct op *t) static int doumask(struct op *t) { - int i, n; + int i; char *cp; cp = t->words[1]; if (cp == NULL) { i = umask(0); umask(i); - for (n = 3 * 4; (n -= 3) >= 0;) - fputc('0' + ((i >> n) & 07), stderr); - fputc('\n', stderr); + printf("%04o\n", i); } else { - for (n = 0; *cp >= '0' && *cp <= '7'; cp++) - n = n * 8 + (*cp - '0'); - umask(n); + i = bb_strtou(cp, NULL, 8); + if (errno) { + err("umask: bad octal number"); + return 1; + } + umask(i); } return 0; } @@ -3292,14 +3281,15 @@ static int doexec(struct op *t) xint *ofail; t->ioact = NULL; - for (i = 0; (t->words[i] = t->words[i + 1]) != NULL; i++); + for (i = 0; (t->words[i] = t->words[i + 1]) != NULL; i++) + continue; if (i == 0) return 1; execflg = 1; ofail = failpt; failpt = ex; if (setjmp(failpt) == 0) - execute(t, NOPIPE, NOPIPE, FEXEC); + execute(t, NOPIPE, NOPIPE, /* no_fork: */ 1); failpt = ofail; execflg = 0; return 1; |