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Diffstat (limited to 'bin/dash/src/redir.c')
| -rw-r--r-- | bin/dash/src/redir.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/bin/dash/src/redir.c b/bin/dash/src/redir.c new file mode 100644 index 00000000..895140c3 --- /dev/null +++ b/bin/dash/src/redir.c @@ -0,0 +1,483 @@ +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * Copyright (c) 1997-2005 + * Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/param.h> /* PIPE_BUF */ +#include <signal.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdlib.h> + +/* + * Code for dealing with input/output redirection. + */ + +#include "main.h" +#include "shell.h" +#include "nodes.h" +#include "jobs.h" +#include "options.h" +#include "expand.h" +#include "redir.h" +#include "output.h" +#include "memalloc.h" +#include "error.h" + + +#define EMPTY -2 /* marks an unused slot in redirtab */ +#define CLOSED -1 /* fd opened for redir needs to be closed */ + +#ifndef PIPE_BUF +# define PIPESIZE 4096 /* amount of buffering in a pipe */ +#else +# define PIPESIZE PIPE_BUF +#endif + + +MKINIT +struct redirtab { + struct redirtab *next; + int renamed[10]; +}; + + +MKINIT struct redirtab *redirlist; + +/* Bit map of currently closed file descriptors. */ +static unsigned closed_redirs; + +STATIC int openredirect(union node *); +#ifdef notyet +STATIC void dupredirect(union node *, int, char[10]); +#else +STATIC void dupredirect(union node *, int); +#endif +STATIC int openhere(union node *); + + +static unsigned update_closed_redirs(int fd, int nfd) +{ + unsigned val = closed_redirs; + unsigned bit = 1 << fd; + + if (nfd >= 0) + closed_redirs &= ~bit; + else + closed_redirs |= bit; + + return val & bit; +} + + +/* + * Process a list of redirection commands. If the REDIR_PUSH flag is set, + * old file descriptors are stashed away so that the redirection can be + * undone by calling popredir. If the REDIR_BACKQ flag is set, then the + * standard output, and the standard error if it becomes a duplicate of + * stdout, is saved in memory. + */ + +void +redirect(union node *redir, int flags) +{ + union node *n; + struct redirtab *sv; + int i; + int fd; + int newfd; + int *p; +#if notyet + char memory[10]; /* file descriptors to write to memory */ + + for (i = 10 ; --i >= 0 ; ) + memory[i] = 0; + memory[1] = flags & REDIR_BACKQ; +#endif + if (!redir) + return; + sv = NULL; + INTOFF; + if (likely(flags & REDIR_PUSH)) + sv = redirlist; + n = redir; + do { + newfd = openredirect(n); + if (newfd < -1) + continue; + + fd = n->nfile.fd; + + if (sv) { + int closed; + + p = &sv->renamed[fd]; + i = *p; + + closed = update_closed_redirs(fd, newfd); + + if (likely(i == EMPTY)) { + i = CLOSED; + if (fd != newfd && !closed) { + i = savefd(fd, fd); + fd = -1; + } + } + + *p = i; + } + + if (fd == newfd) + continue; + +#ifdef notyet + dupredirect(n, newfd, memory); +#else + dupredirect(n, newfd); +#endif + } while ((n = n->nfile.next)); + INTON; +#ifdef notyet + if (memory[1]) + out1 = &memout; + if (memory[2]) + out2 = &memout; +#endif + if (flags & REDIR_SAVEFD2 && sv->renamed[2] >= 0) + preverrout.fd = sv->renamed[2]; +} + + +STATIC int +openredirect(union node *redir) +{ + struct stat64 sb; + char *fname; + int f; + + switch (redir->nfile.type) { + case NFROM: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_RDONLY)) < 0) + goto eopen; + break; + case NFROMTO: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_RDWR|O_CREAT, 0666)) < 0) + goto ecreate; + break; + case NTO: + /* Take care of noclobber mode. */ + if (Cflag) { + fname = redir->nfile.expfname; + if (stat64(fname, &sb) < 0) { + if ((f = open64(fname, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0) + goto ecreate; + } else if (!S_ISREG(sb.st_mode)) { + if ((f = open64(fname, O_WRONLY, 0666)) < 0) + goto ecreate; + if (!fstat64(f, &sb) && S_ISREG(sb.st_mode)) { + close(f); + errno = EEXIST; + goto ecreate; + } + } else { + errno = EEXIST; + goto ecreate; + } + break; + } + /* FALLTHROUGH */ + case NCLOBBER: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0) + goto ecreate; + break; + case NAPPEND: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0) + goto ecreate; + break; + case NTOFD: + case NFROMFD: + f = redir->ndup.dupfd; + if (f == redir->nfile.fd) + f = -2; + break; + default: +#ifdef DEBUG + abort(); +#endif + /* Fall through to eliminate warning. */ + case NHERE: + case NXHERE: + f = openhere(redir); + break; + } + + return f; +ecreate: + sh_error("cannot create %s: %s", fname, errmsg(errno, E_CREAT)); +eopen: + sh_error("cannot open %s: %s", fname, errmsg(errno, E_OPEN)); +} + + +STATIC void +#ifdef notyet +dupredirect(redir, f, memory) +#else +dupredirect(redir, f) +#endif + union node *redir; + int f; +#ifdef notyet + char memory[10]; +#endif + { + int fd = redir->nfile.fd; + int err = 0; + +#ifdef notyet + memory[fd] = 0; +#endif + if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) { + /* if not ">&-" */ + if (f >= 0) { +#ifdef notyet + if (memory[f]) + memory[fd] = 1; + else +#endif + if (dup2(f, fd) < 0) { + err = errno; + goto err; + } + return; + } + f = fd; + } else if (dup2(f, fd) < 0) + err = errno; + + close(f); + if (err < 0) + goto err; + + return; + +err: + sh_error("%d: %s", f, strerror(err)); +} + + +/* + * Handle here documents. Normally we fork off a process to write the + * data to a pipe. If the document is short, we can stuff the data in + * the pipe without forking. + */ + +STATIC int +openhere(union node *redir) +{ + char *p; + int pip[2]; + size_t len = 0; + + if (pipe(pip) < 0) + sh_error("Pipe call failed"); + + p = redir->nhere.doc->narg.text; + if (redir->type == NXHERE) { + expandarg(redir->nhere.doc, NULL, EXP_QUOTED); + p = stackblock(); + } + + len = strlen(p); + if (len <= PIPESIZE) { + xwrite(pip[1], p, len); + goto out; + } + + if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { + close(pip[0]); + signal(SIGINT, SIG_IGN); + signal(SIGQUIT, SIG_IGN); + signal(SIGHUP, SIG_IGN); +#ifdef SIGTSTP + signal(SIGTSTP, SIG_IGN); +#endif + signal(SIGPIPE, SIG_DFL); + xwrite(pip[1], p, len); + _exit(0); + } +out: + close(pip[1]); + return pip[0]; +} + + + +/* + * Undo the effects of the last redirection. + */ + +void +popredir(int drop) +{ + struct redirtab *rp; + int i; + + INTOFF; + rp = redirlist; + for (i = 0 ; i < 10 ; i++) { + int closed; + + if (rp->renamed[i] == EMPTY) + continue; + + closed = drop ? 1 : update_closed_redirs(i, rp->renamed[i]); + + switch (rp->renamed[i]) { + case CLOSED: + if (!closed) + close(i); + break; + default: + if (!drop) + dup2(rp->renamed[i], i); + close(rp->renamed[i]); + break; + } + } + redirlist = rp->next; + ckfree(rp); + INTON; +} + +/* + * Undo all redirections. Called on error or interrupt. + */ + +#ifdef mkinit + +INCLUDE "redir.h" + +EXITRESET { + /* + * Discard all saved file descriptors. + */ + unwindredir(0); +} + +FORKRESET { + redirlist = NULL; +} + +#endif + + + +/* + * Move a file descriptor to > 10. Invokes sh_error on error unless + * the original file dscriptor is not open. + */ + +int +savefd(int from, int ofd) +{ + int newfd; + int err; + + newfd = fcntl(from, F_DUPFD, 10); + err = newfd < 0 ? errno : 0; + if (err != EBADF) { + close(ofd); + if (err) + sh_error("%d: %s", from, strerror(err)); + else + fcntl(newfd, F_SETFD, FD_CLOEXEC); + } + + return newfd; +} + + +int +redirectsafe(union node *redir, int flags) +{ + int err; + volatile int saveint; + struct jmploc *volatile savehandler = handler; + struct jmploc jmploc; + + SAVEINT(saveint); + if (!(err = setjmp(jmploc.loc) * 2)) { + handler = &jmploc; + redirect(redir, flags); + } + handler = savehandler; + if (err && exception != EXERROR) + longjmp(handler->loc, 1); + RESTOREINT(saveint); + return err; +} + + +void unwindredir(struct redirtab *stop) +{ + while (redirlist != stop) + popredir(0); +} + + +struct redirtab *pushredir(union node *redir) +{ + struct redirtab *sv; + struct redirtab *q; + int i; + + q = redirlist; + if (!redir) + goto out; + + sv = ckmalloc(sizeof (struct redirtab)); + sv->next = q; + redirlist = sv; + for (i = 0; i < 10; i++) + sv->renamed[i] = EMPTY; + +out: + return q; +} |