diff options
Diffstat (limited to 'libtar/encode.c')
| -rw-r--r-- | libtar/encode.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/libtar/encode.c b/libtar/encode.c new file mode 100644 index 000000000..c9371527b --- /dev/null +++ b/libtar/encode.c @@ -0,0 +1,238 @@ +/* +** Copyright 1998-2003 University of Illinois Board of Trustees +** Copyright 1998-2003 Mark D. Roth +** All rights reserved. +** +** encode.c - libtar code to encode tar header blocks +** +** Mark D. Roth <roth@uiuc.edu> +** Campus Information Technologies and Educational Services +** University of Illinois at Urbana-Champaign +*/ + +#include <internal.h> + +#include <stdio.h> +#include <pwd.h> +#include <grp.h> +#include <sys/types.h> + +#ifdef STDC_HEADERS +# include <string.h> +# include <stdlib.h> +#endif + + +/* magic, version, and checksum */ +void +th_finish(TAR *t) +{ + if (t->options & TAR_GNU) + { + /* we're aiming for this result, but must do it in + * two calls to avoid FORTIFY segfaults on some Linux + * systems: + * strncpy(t->th_buf.magic, "ustar ", 8); + */ + strncpy(t->th_buf.magic, "ustar ", 6); + strncpy(t->th_buf.version, " ", 2); + } + else + { + strncpy(t->th_buf.version, TVERSION, TVERSLEN); + strncpy(t->th_buf.magic, TMAGIC, TMAGLEN); + } + + int_to_oct(th_crc_calc(t), t->th_buf.chksum, 8); +} + + +/* map a file mode to a typeflag */ +void +th_set_type(TAR *t, mode_t mode) +{ + if (S_ISLNK(mode)) + t->th_buf.typeflag = SYMTYPE; + if (S_ISREG(mode)) + t->th_buf.typeflag = REGTYPE; + if (S_ISDIR(mode)) + t->th_buf.typeflag = DIRTYPE; + if (S_ISCHR(mode)) + t->th_buf.typeflag = CHRTYPE; + if (S_ISBLK(mode)) + t->th_buf.typeflag = BLKTYPE; + if (S_ISFIFO(mode) || S_ISSOCK(mode)) + t->th_buf.typeflag = FIFOTYPE; +} + + +/* encode file path */ +void +th_set_path(TAR *t, const char *pathname) +{ + char suffix[2] = ""; + char *tmp; + size_t pathname_len = strlen(pathname); + +#ifdef DEBUG + printf("in th_set_path(th, pathname=\"%s\")\n", pathname); +#endif + + if (t->th_buf.gnu_longname != NULL) + free(t->th_buf.gnu_longname); + t->th_buf.gnu_longname = NULL; + + /* old archive compatibility (not needed for gnu): add trailing / to directories */ + if (pathname[pathname_len - 1] != '/' && TH_ISDIR(t)) + strcpy(suffix, "/"); + + if (pathname_len >= T_NAMELEN && (t->options & TAR_GNU)) + { + /* GNU-style long name (no file name length limit) */ + t->th_buf.gnu_longname = strdup(pathname); + strncpy(t->th_buf.name, t->th_buf.gnu_longname, T_NAMELEN); + } + else if (pathname_len >= T_NAMELEN) + { + /* POSIX-style prefix field: + * The maximum length of a file name is limited to 256 characters, + * provided that the file name can be split at a directory separator + * in two parts. The first part being at most 155 bytes long and + * the second part being at most 100 bytes long. So, in most cases + * the maximum file name length will be shorter than 256 characters. + */ + char tail_path[T_NAMELEN + 1]; + tmp = strchr(&(pathname[pathname_len - T_NAMELEN]), '/'); + if (tmp == NULL) + { + printf("!!! '/' not found in \"%s\"\n", pathname); + return; + } + snprintf(tail_path, T_NAMELEN + 1, "%s%s", &tmp[1], suffix); + strncpy(t->th_buf.name, tail_path, T_NAMELEN); + + /* + * first part, max = 155 == sizeof(t->th_buf.prefix) , include NULL if it fits + * trailing '/' is added during decode: decode.c/th_get_pathname() + */ + if (tmp - pathname >= 155) { + strncpy(t->th_buf.prefix, pathname, 155); + } else { + snprintf(t->th_buf.prefix, (tmp - pathname + 1), "%s", pathname); + } + } + else { + /* any short name for all formats, or classic tar format (99 chars max) */ + snprintf(t->th_buf.name, T_NAMELEN, "%s%s", pathname, suffix); + } + +#ifdef DEBUG + puts("returning from th_set_path()..."); +#endif +} + + +/* encode link path */ +void +th_set_link(TAR *t, const char *linkname) +{ +#ifdef DEBUG + printf("==> th_set_link(th, linkname=\"%s\")\n", linkname); +#endif + + if (strlen(linkname) >= T_NAMELEN && (t->options & TAR_GNU)) + { + /* --format=gnu: GNU-style long name (no file name length limit) */ + t->th_buf.gnu_longlink = strdup(linkname); + strcpy(t->th_buf.linkname, "././@LongLink"); + } + else if (strlen(linkname) >= T_NAMELEN) + { + /* --format=ustar: 100 chars max limit for symbolic links */ + strncpy(t->th_buf.linkname, linkname, T_NAMELEN); + if (t->th_buf.gnu_longlink != NULL) + free(t->th_buf.gnu_longlink); + t->th_buf.gnu_longlink = NULL; + } else { + /* all short links or v7 tar format: The maximum length of a symbolic link name is limited to 99 characters */ + snprintf(t->th_buf.linkname, T_NAMELEN, "%s", linkname); + if (t->th_buf.gnu_longlink != NULL) + free(t->th_buf.gnu_longlink); + t->th_buf.gnu_longlink = NULL; + } +} + + +/* encode device info */ +void +th_set_device(TAR *t, dev_t device) +{ +#ifdef DEBUG + printf("th_set_device(): major = %d, minor = %d\n", + major(device), minor(device)); +#endif + int_to_oct(major(device), t->th_buf.devmajor, 8); + int_to_oct(minor(device), t->th_buf.devminor, 8); +} + + +/* encode user info */ +void +th_set_user(TAR *t, uid_t uid) +{ + struct passwd *pw; + + if (!(t->options & TAR_USE_NUMERIC_ID)) { + pw = getpwuid(uid); + if (pw != NULL) + strlcpy(t->th_buf.uname, pw->pw_name, sizeof(t->th_buf.uname)); + } + + int_to_oct(uid, t->th_buf.uid, 8); +} + + +/* encode group info */ +void +th_set_group(TAR *t, gid_t gid) +{ + struct group *gr; + + if (!(t->options & TAR_USE_NUMERIC_ID)) { + gr = getgrgid(gid); + if (gr != NULL) + strlcpy(t->th_buf.gname, gr->gr_name, sizeof(t->th_buf.gname)); + } + + int_to_oct(gid, t->th_buf.gid, 8); +} + + +/* encode file mode */ +void +th_set_mode(TAR *t, mode_t fmode) +{ + if (S_ISSOCK(fmode)) + { + fmode &= ~S_IFSOCK; + fmode |= S_IFIFO; + } + int_to_oct(fmode, (t)->th_buf.mode, 8); +} + + +void +th_set_from_stat(TAR *t, struct stat *s) +{ + th_set_type(t, s->st_mode); + if (S_ISCHR(s->st_mode) || S_ISBLK(s->st_mode)) + th_set_device(t, s->st_rdev); + th_set_user(t, s->st_uid); + th_set_group(t, s->st_gid); + th_set_mode(t, s->st_mode); + th_set_mtime(t, s->st_mtime); + if (S_ISREG(s->st_mode)) + th_set_size(t, s->st_size); + else + th_set_size(t, 0); +} |