X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=blobdiff_plain;f=src%2Fmisc.c;h=e92c8aa830e36fe2fca6cd25aeaf9f107d7b6bac;hp=b75f2ab4e419e4f9a928e75b25342630f2ad17ec;hb=45ccda119355a1087450039a250359c1d0de0d08;hpb=280751384120a61d8858bea0217061a98434f073 diff --git a/src/misc.c b/src/misc.c index b75f2ab..e92c8aa 100644 --- a/src/misc.c +++ b/src/misc.c @@ -1,7 +1,7 @@ /* Miscellaneous functions, not really specific to GNU tar. - Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001, - 2003, 2004, 2005, 2006, 2007, 2009, 2010 Free Software Foundation, Inc. + Copyright 1988, 1992, 1994-1997, 1999-2001, 2003-2007, 2009-2010, + 2012-2014 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the @@ -14,9 +14,9 @@ Public License for more details. You should have received a copy of the GNU General Public License along - with this program; if not, write to the Free Software Foundation, Inc., - 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + with this program. If not, see . */ +#define COMMON_INLINE _GL_EXTERN_INLINE #include #include #include "common.h" @@ -29,6 +29,8 @@ # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0 #endif +static const char *tar_getcdpath (int); + /* Handling strings. */ @@ -105,7 +107,7 @@ quote_copy_string (const char *string) completes the unquoting anyway. This is used for reading the saved directory file in incremental - dumps. It is used for decoding old `N' records (demangling names). + dumps. It is used for decoding old 'N' records (demangling names). But also, it is used for decoding file arguments, would they come from the shell or a -T file, and for decoding the --exclude argument. */ @@ -229,11 +231,12 @@ zap_slashes (char *name) } /* Normalize FILE_NAME by removing redundant slashes and "." - components, including redundant trailing slashes. Leave ".." - alone, as it may be significant in the presence of symlinks and on - platforms where "/.." != "/". Destructive version: modifies its - argument. */ -static void + components, including redundant trailing slashes. + Leave ".." alone, as it may be significant in the presence + of symlinks and on platforms where "/.." != "/". + + Destructive version: modifies its argument. */ +void normalize_filename_x (char *file_name) { char *name = file_name + FILE_SYSTEM_PREFIX_LEN (file_name); @@ -267,37 +270,41 @@ normalize_filename_x (char *file_name) } /* Normalize NAME by removing redundant slashes and "." components, - including redundant trailing slashes. Return a normalized - newly-allocated copy. */ + including redundant trailing slashes. + + Return a normalized newly-allocated copy. */ char * -normalize_filename (const char *name) +normalize_filename (int cdidx, const char *name) { char *copy = NULL; if (IS_RELATIVE_FILE_NAME (name)) { - /* Set COPY to the absolute file name if possible. + /* Set COPY to the absolute path for this name. FIXME: There should be no need to get the absolute file name. - getcwd is slow, it might fail, and it does not necessarily - return a canonical name even when it succeeds. Perhaps we - can use dev+ino pairs instead of names? */ - copy = xgetcwd (); - if (copy) - { - size_t copylen = strlen (copy); - bool need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT - && copylen == 2 && ISSLASH (copy[1])); - copy = xrealloc (copy, copylen + need_separator + strlen (name) + 1); - copy[copylen] = DIRECTORY_SEPARATOR; - strcpy (copy + copylen + need_separator, name); - } - else - WARN ((0, errno, _("Cannot get working directory"))); + tar_getcdpath does not return a true "canonical" path, so + this following approach may lead to situations where the same + file or directory is processed twice under different absolute + paths without that duplication being detected. Perhaps we + should use dev+ino pairs instead of names? */ + const char *cdpath = tar_getcdpath (cdidx); + size_t copylen; + bool need_separator; + + if (!cdpath) + call_arg_fatal ("getcwd", "."); + copylen = strlen (cdpath); + need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT + && copylen == 2 && ISSLASH (cdpath[1])); + copy = xmalloc (copylen + need_separator + strlen (name) + 1); + strcpy (copy, cdpath); + copy[copylen] = DIRECTORY_SEPARATOR; + strcpy (copy + copylen + need_separator, name); } - if (! copy) + if (!copy) copy = xstrdup (name); normalize_filename_x (copy); return copy; @@ -325,6 +332,76 @@ replace_prefix (char **pname, const char *samp, size_t slen, /* Handling numbers. */ +/* Convert VALUE, which is converted from a system integer type whose + minimum value is MINVAL and maximum MINVAL, to an decimal + integer string. Use the storage in BUF and return a pointer to the + converted string. If VALUE is converted from a negative integer in + the range MINVAL .. -1, represent it with a string representation + of the negative integer, using leading '-'. */ +#if ! (INTMAX_MAX <= UINTMAX_MAX / 2) +# error "sysinttostr: uintmax_t cannot represent all intmax_t values" +#endif +char * +sysinttostr (uintmax_t value, intmax_t minval, uintmax_t maxval, + char buf[SYSINT_BUFSIZE]) +{ + if (value <= maxval) + return umaxtostr (value, buf); + else + { + intmax_t i = value - minval; + return imaxtostr (i + minval, buf); + } +} + +/* Convert a prefix of the string ARG to a system integer type whose + minimum value is MINVAL and maximum MAXVAL. If MINVAL is negative, + negative integers MINVAL .. -1 are assumed to be represented using + leading '-' in the usual way. If the represented value exceeds + INTMAX_MAX, return a negative integer V such that (uintmax_t) V + yields the represented value. If ARGLIM is nonnull, store into + *ARGLIM a pointer to the first character after the prefix. + + This is the inverse of sysinttostr. + + On a normal return, set errno = 0. + On conversion error, return 0 and set errno = EINVAL. + On overflow, return an extreme value and set errno = ERANGE. */ +#if ! (INTMAX_MAX <= UINTMAX_MAX) +# error "strtosysint: nonnegative intmax_t does not fit in uintmax_t" +#endif +intmax_t +strtosysint (char const *arg, char **arglim, intmax_t minval, uintmax_t maxval) +{ + errno = 0; + if (maxval <= INTMAX_MAX) + { + if (ISDIGIT (arg[*arg == '-'])) + { + intmax_t i = strtoimax (arg, arglim, 10); + intmax_t imaxval = maxval; + if (minval <= i && i <= imaxval) + return i; + errno = ERANGE; + return i < minval ? minval : maxval; + } + } + else + { + if (ISDIGIT (*arg)) + { + uintmax_t i = strtoumax (arg, arglim, 10); + if (i <= maxval) + return represent_uintmax (i); + errno = ERANGE; + return maxval; + } + } + + errno = EINVAL; + return 0; +} + /* Output fraction and trailing digits appropriate for a nanoseconds count equal to NS, but don't output unnecessary '.' or trailing zeros. */ @@ -381,6 +458,84 @@ code_timespec (struct timespec t, char sbuf[TIMESPEC_STRSIZE_BOUND]) code_ns_fraction (ns, sbuf + UINTMAX_STRSIZE_BOUND); return np; } + +struct timespec +decode_timespec (char const *arg, char **arg_lim, bool parse_fraction) +{ + time_t s = TYPE_MINIMUM (time_t); + int ns = -1; + char const *p = arg; + bool negative = *arg == '-'; + struct timespec r; + + if (! ISDIGIT (arg[negative])) + errno = EINVAL; + else + { + errno = 0; + + if (negative) + { + intmax_t i = strtoimax (arg, arg_lim, 10); + if (TYPE_SIGNED (time_t) ? TYPE_MINIMUM (time_t) <= i : 0 <= i) + s = i; + else + errno = ERANGE; + } + else + { + uintmax_t i = strtoumax (arg, arg_lim, 10); + if (i <= TYPE_MAXIMUM (time_t)) + s = i; + else + errno = ERANGE; + } + + p = *arg_lim; + ns = 0; + + if (parse_fraction && *p == '.') + { + int digits = 0; + bool trailing_nonzero = false; + + while (ISDIGIT (*++p)) + if (digits < LOG10_BILLION) + digits++, ns = 10 * ns + (*p - '0'); + else + trailing_nonzero |= *p != '0'; + + while (digits < LOG10_BILLION) + digits++, ns *= 10; + + if (negative) + { + /* Convert "-1.10000000000001" to s == -2, ns == 89999999. + I.e., truncate time stamps towards minus infinity while + converting them to internal form. */ + ns += trailing_nonzero; + if (ns != 0) + { + if (s == TYPE_MINIMUM (time_t)) + ns = -1; + else + { + s--; + ns = BILLION - ns; + } + } + } + } + + if (errno == ERANGE) + ns = -1; + } + + *arg_lim = (char *) p; + r.tv_sec = s; + r.tv_nsec = ns; + return r; +} /* File handling. */ @@ -483,7 +638,7 @@ remove_any_file (const char *file_name, enum remove_option option) case RECURSIVE_REMOVE_OPTION: { - char *directory = savedir (file_name); + char *directory = tar_savedir (file_name, 0); char const *entry; size_t entrylen; @@ -616,6 +771,57 @@ deref_stat (char const *name, struct stat *buf) return fstatat (chdir_fd, name, buf, fstatat_flags); } +/* Read from FD into the buffer BUF with COUNT bytes. Attempt to fill + BUF. Wait until input is available; this matters because files are + opened O_NONBLOCK for security reasons, and on some file systems + this can cause read to fail with errno == EAGAIN. Return the + actual number of bytes read, zero for EOF, or + SAFE_READ_ERROR upon error. */ +size_t +blocking_read (int fd, void *buf, size_t count) +{ + size_t bytes = safe_read (fd, buf, count); + +#if defined F_SETFL && O_NONBLOCK + if (bytes == SAFE_READ_ERROR && errno == EAGAIN) + { + int flags = fcntl (fd, F_GETFL); + if (0 <= flags && flags & O_NONBLOCK + && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1) + bytes = safe_read (fd, buf, count); + } +#endif + + return bytes; +} + +/* Write to FD from the buffer BUF with COUNT bytes. Do a full write. + Wait until an output buffer is available; this matters because + files are opened O_NONBLOCK for security reasons, and on some file + systems this can cause write to fail with errno == EAGAIN. Return + the actual number of bytes written, setting errno if that is less + than COUNT. */ +size_t +blocking_write (int fd, void const *buf, size_t count) +{ + size_t bytes = full_write (fd, buf, count); + +#if defined F_SETFL && O_NONBLOCK + if (bytes < count && errno == EAGAIN) + { + int flags = fcntl (fd, F_GETFL); + if (0 <= flags && flags & O_NONBLOCK + && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1) + { + char const *buffer = buf; + bytes += full_write (fd, buffer + bytes, count - bytes); + } + } +#endif + + return bytes; +} + /* Set FD's (i.e., assuming the working directory is PARENTFD, FILE's) access time to ATIME. */ int @@ -632,7 +838,11 @@ struct wd { /* The directory's name. */ char const *name; - + /* "Absolute" path representing this directory; in the contrast to + the real absolute pathname, it can contain /../ components (see + normalize_filename_x for the reason of it). It is NULL if the + absolute path could not be determined. */ + char *abspath; /* If nonzero, the file descriptor of the directory, or AT_FDCWD if the working directory. If zero, the directory needs to be opened to be used. */ @@ -662,7 +872,7 @@ static int wdcache[CHDIR_CACHE_SIZE]; static size_t wdcache_count; int -chdir_count () +chdir_count (void) { if (wd_count == 0) return wd_count; @@ -674,19 +884,18 @@ chdir_count () int chdir_arg (char const *dir) { + char *absdir; + if (wd_count == wd_alloc) { if (wd_alloc == 0) - { - wd_alloc = 2; - wd = xmalloc (sizeof *wd * wd_alloc); - } - else - wd = x2nrealloc (wd, &wd_alloc, sizeof *wd); + wd_alloc = 2; + wd = x2nrealloc (wd, &wd_alloc, sizeof *wd); if (! wd_count) { wd[wd_count].name = "."; + wd[wd_count].abspath = xgetcwd (); wd[wd_count].fd = AT_FDCWD; wd_count++; } @@ -703,7 +912,22 @@ chdir_arg (char const *dir) return wd_count - 1; } + + /* If the given name is absolute, use it to represent this directory; + otherwise, construct a name based on the previous -C option. */ + if (IS_ABSOLUTE_FILE_NAME (dir)) + absdir = xstrdup (dir); + else if (wd[wd_count - 1].abspath) + { + namebuf_t nbuf = namebuf_create (wd[wd_count - 1].abspath); + namebuf_add_dir (nbuf, dir); + absdir = namebuf_finish (nbuf); + } + else + absdir = 0; + wd[wd_count].name = dir; + wd[wd_count].abspath = absdir; wd[wd_count].fd = 0; return wd_count++; } @@ -763,11 +987,11 @@ chdir_do (int i) int prev = wdcache[0]; for (ci = 1; prev != i; ci++) { - int curr = wdcache[ci]; + int cur = wdcache[ci]; wdcache[ci] = prev; - if (curr == i) + if (cur == i) break; - prev = curr; + prev = cur; } wdcache[0] = i; } @@ -777,6 +1001,32 @@ chdir_do (int i) } } +const char * +tar_dirname (void) +{ + return wd[chdir_current].name; +} + +/* Return the absolute path that represents the working + directory referenced by IDX. + + If wd is empty, then there were no -C options given, and + chdir_args() has never been called, so we simply return the + process's actual cwd. (Note that in this case IDX is ignored, + since it should always be 0.) */ +static const char * +tar_getcdpath (int idx) +{ + if (!wd) + { + static char *cwd; + if (!cwd) + cwd = xgetcwd (); + return cwd; + } + return wd[idx].abspath; +} + void close_diag (char const *name) { @@ -911,7 +1161,7 @@ page_aligned_alloc (void **ptr, size_t size) struct namebuf { - char *buffer; /* directory, `/', and directory member */ + char *buffer; /* directory, '/', and directory member */ size_t buffer_size; /* allocated size of name_buffer */ size_t dir_length; /* length of directory part in buffer */ }; @@ -945,3 +1195,55 @@ namebuf_name (namebuf_t buf, const char *name) strcpy (buf->buffer + buf->dir_length, name); return buf->buffer; } + +void +namebuf_add_dir (namebuf_t buf, const char *name) +{ + static char dirsep[] = { DIRECTORY_SEPARATOR, 0 }; + if (!ISSLASH (buf->buffer[buf->dir_length - 1])) + { + namebuf_name (buf, dirsep); + buf->dir_length++; + } + namebuf_name (buf, name); + buf->dir_length += strlen (name); +} + +char * +namebuf_finish (namebuf_t buf) +{ + char *res = buf->buffer; + + if (ISSLASH (buf->buffer[buf->dir_length - 1])) + buf->buffer[buf->dir_length] = 0; + free (buf); + return res; +} + +/* Return the filenames in directory NAME, relative to the chdir_fd. + If the directory does not exist, report error if MUST_EXIST is + true. + + Return NULL on errors. +*/ +char * +tar_savedir (const char *name, int must_exist) +{ + char *ret = NULL; + DIR *dir = NULL; + int fd = openat (chdir_fd, name, open_read_flags | O_DIRECTORY); + if (fd < 0) + { + if (!must_exist && errno == ENOENT) + return NULL; + open_error (name); + } + else if (! ((dir = fdopendir (fd)) + && (ret = streamsavedir (dir)))) + savedir_error (name); + + if (dir ? closedir (dir) != 0 : 0 <= fd && close (fd) != 0) + savedir_error (name); + + return ret; +}