From: Paul Eggert Date: Mon, 12 Sep 2005 18:45:59 +0000 (+0000) Subject: Treat fishy-looking hard links like fishy-looking symlinks. X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=commitdiff_plain;h=af5d05729ade7f6d6f1552df31bce4c3dbc37247 Treat fishy-looking hard links like fishy-looking symlinks. (struct delayed_set_stat): Rename after_symlinks member to after_links. All uses changed. (struct delayed_link): Renamed from struct delayed_symlink. All uses changed. New member is_symlink. (delayed_link_head): Renamed from delayed_symlink_head. All uses changed. (create_placeholder_file): New function, taken from extract_symlink. (extract_link): Create placeholders for fishy-looking hard links. (extract_symlink): Move code into create_placeholder_file. (apply_delayed_links): Renamed from apply_delayed_symlinks. All uses changed. Create both hard links and symlinks. --- diff --git a/src/extract.c b/src/extract.c index 9be0a8b..d835813 100644 --- a/src/extract.c +++ b/src/extract.c @@ -48,8 +48,8 @@ enum permstatus /* List of directories whose statuses we need to extract after we've finished extracting their subsidiary files. If you consider each contiguous subsequence of elements of the form [D]?[^D]*, where [D] - represents an element where AFTER_SYMLINKS is nonzero and [^D] - represents an element where AFTER_SYMLINKS is zero, then the head + represents an element where AFTER_LINKS is nonzero and [^D] + represents an element where AFTER_LINKS is zero, then the head of the subsequence has the longest name, and each non-head element in the prefix is an ancestor (in the directory hierarchy) of the preceding element. */ @@ -61,28 +61,31 @@ struct delayed_set_stat size_t file_name_len; mode_t invert_permissions; enum permstatus permstatus; - bool after_symlinks; + bool after_links; char file_name[1]; }; static struct delayed_set_stat *delayed_set_stat_head; -/* List of symbolic links whose creation we have delayed. */ -struct delayed_symlink +/* List of links whose creation we have delayed. */ +struct delayed_link { - /* The next delayed symbolic link in the list. */ - struct delayed_symlink *next; + /* The next delayed link in the list. */ + struct delayed_link *next; /* The device, inode number and last-modified time of the placeholder. */ dev_t dev; ino_t ino; time_t mtime; - /* The desired owner and group of the symbolic link. */ + /* True if the link is symbolic. */ + bool is_symlink; + + /* The desired owner and group of the link, if it is a symlink. */ uid_t uid; gid_t gid; - /* A list of sources for this symlink. The sources are all to be + /* A list of sources for this link. The sources are all to be hard-linked together. */ struct string_list *sources; @@ -90,7 +93,7 @@ struct delayed_symlink char target[1]; }; -static struct delayed_symlink *delayed_symlink_head; +static struct delayed_link *delayed_link_head; struct string_list { @@ -322,7 +325,7 @@ delay_set_stat (char const *file_name, struct stat const *stat_info, strcpy (data->file_name, file_name); data->invert_permissions = invert_permissions; data->permstatus = permstatus; - data->after_symlinks = 0; + data->after_links = 0; data->stat_info = *stat_info; data->next = delayed_set_stat_head; delayed_set_stat_head = data; @@ -361,7 +364,7 @@ repair_delayed_set_stat (char const *dir, quotearg_colon (dir))); } -/* After a file/link/symlink/directory creation has failed, see if +/* After a file/link/directory creation has failed, see if it's because some required directory was not present, and if so, create all required directories. Return non-zero if a directory was created. */ @@ -513,12 +516,12 @@ maybe_recoverable (char *file_name, int *interdir_made) } /* Fix the statuses of all directories whose statuses need fixing, and - which are not ancestors of FILE_NAME. If AFTER_SYMLINKS is + which are not ancestors of FILE_NAME. If AFTER_LINKS is nonzero, do this for all such directories; otherwise, stop at the first directory that is marked to be fixed up only after delayed - symlinks are applied. */ + links are applied. */ static void -apply_nonancestor_delayed_set_stat (char const *file_name, bool after_symlinks) +apply_nonancestor_delayed_set_stat (char const *file_name, bool after_links) { size_t file_name_len = strlen (file_name); bool check_for_renamed_directories = 0; @@ -530,9 +533,9 @@ apply_nonancestor_delayed_set_stat (char const *file_name, bool after_symlinks) struct stat st; struct stat const *cur_info = 0; - check_for_renamed_directories |= data->after_symlinks; + check_for_renamed_directories |= data->after_links; - if (after_symlinks < data->after_symlinks + if (after_links < data->after_links || (data->file_name_len < file_name_len && file_name[data->file_name_len] && (ISSLASH (file_name[data->file_name_len]) @@ -776,6 +779,82 @@ extract_file (char *file_name, int typeflag) return status; } +/* Create a placeholder file with name FILE_NAME, which will be + replaced after other extraction is done by a symbolic link if + IS_SYMLINK is true, and by a hard link otherwise. Set + *INTERDIR_MADE if an intermediate directory is made in the + process. */ + +static int +create_placeholder_file (char *file_name, bool is_symlink, int *interdir_made) +{ + int fd; + struct stat st; + + while ((fd = open (file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0) + if (! maybe_recoverable (file_name, interdir_made)) + break; + + if (fd < 0) + open_error (file_name); + else if (fstat (fd, &st) != 0) + { + stat_error (file_name); + close (fd); + } + else if (close (fd) != 0) + close_error (file_name); + else + { + struct delayed_set_stat *h; + struct delayed_link *p = + xmalloc (offsetof (struct delayed_link, target) + + strlen (current_stat_info.link_name) + + 1); + p->next = delayed_link_head; + delayed_link_head = p; + p->dev = st.st_dev; + p->ino = st.st_ino; + p->mtime = st.st_mtime; + p->is_symlink = is_symlink; + if (is_symlink) + { + p->uid = current_stat_info.stat.st_uid; + p->gid = current_stat_info.stat.st_gid; + } + p->sources = xmalloc (offsetof (struct string_list, string) + + strlen (file_name) + 1); + p->sources->next = 0; + strcpy (p->sources->string, file_name); + strcpy (p->target, current_stat_info.link_name); + + h = delayed_set_stat_head; + if (h && ! h->after_links + && strncmp (file_name, h->file_name, h->file_name_len) == 0 + && ISSLASH (file_name[h->file_name_len]) + && (base_name (file_name) == file_name + h->file_name_len + 1)) + { + do + { + h->after_links = 1; + + if (stat (h->file_name, &st) != 0) + stat_error (h->file_name); + else + { + h->stat_info.st_dev = st.st_dev; + h->stat_info.st_ino = st.st_ino; + } + } + while ((h = h->next) && ! h->after_links); + } + + return 0; + } + + return -1; +} + static int extract_link (char *file_name, int typeflag) { @@ -783,6 +862,9 @@ extract_link (char *file_name, int typeflag) true, absolute_names_option); int interdir_made = 0; + if (! absolute_names_option && contains_dot_dot (link_name)) + return create_placeholder_file (file_name, false, &interdir_made); + do { struct stat st1, st2; @@ -792,7 +874,7 @@ extract_link (char *file_name, int typeflag) if (status == 0) { - struct delayed_symlink *ds = delayed_symlink_head; + struct delayed_link *ds = delayed_link_head; if (ds && lstat (link_name, &st1) == 0) for (; ds; ds = ds->next) if (ds->dev == st1.st_dev @@ -831,87 +913,22 @@ static int extract_symlink (char *file_name, int typeflag) { #ifdef HAVE_SYMLINK - int status, fd; + int status; int interdir_made = 0; - if (absolute_names_option - || ! (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name) - || contains_dot_dot (current_stat_info.link_name))) - { - while ((status = symlink (current_stat_info.link_name, file_name))) - if (!maybe_recoverable (file_name, &interdir_made)) - break; - - if (status == 0) - set_stat (file_name, ¤t_stat_info.stat, 0, 0, 0, SYMTYPE); - else - symlink_error (current_stat_info.link_name, file_name); - } - else - { - /* This symbolic link is potentially dangerous. Don't - create it now; instead, create a placeholder file, which - will be replaced after other extraction is done. */ - struct stat st; - - while ((fd = open (file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0) - if (! maybe_recoverable (file_name, &interdir_made)) - break; - - status = -1; - if (fd < 0) - open_error (file_name); - else if (fstat (fd, &st) != 0) - { - stat_error (file_name); - close (fd); - } - else if (close (fd) != 0) - close_error (file_name); - else - { - struct delayed_set_stat *h; - struct delayed_symlink *p = xmalloc (offsetof (struct delayed_symlink, target) - + strlen (current_stat_info.link_name) - + 1); - p->next = delayed_symlink_head; - delayed_symlink_head = p; - p->dev = st.st_dev; - p->ino = st.st_ino; - p->mtime = st.st_mtime; - p->uid = current_stat_info.stat.st_uid; - p->gid = current_stat_info.stat.st_gid; - p->sources = xmalloc (offsetof (struct string_list, string) - + strlen (file_name) + 1); - p->sources->next = 0; - strcpy (p->sources->string, file_name); - strcpy (p->target, current_stat_info.link_name); - - h = delayed_set_stat_head; - if (h && ! h->after_symlinks - && strncmp (file_name, h->file_name, h->file_name_len) == 0 - && ISSLASH (file_name[h->file_name_len]) - && (base_name (file_name) == file_name + h->file_name_len + 1)) - { - do - { - h->after_symlinks = 1; - - if (stat (h->file_name, &st) != 0) - stat_error (h->file_name); - else - { - h->stat_info.st_dev = st.st_dev; - h->stat_info.st_ino = st.st_ino; - } - } - while ((h = h->next) && ! h->after_symlinks); - } + if (! absolute_names_option + && (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name) + || contains_dot_dot (current_stat_info.link_name))) + return create_placeholder_file (file_name, true, &interdir_made); - status = 0; - } - } + while ((status = symlink (current_stat_info.link_name, file_name))) + if (!maybe_recoverable (file_name, &interdir_made)) + break; + if (status == 0) + set_stat (file_name, ¤t_stat_info.stat, 0, 0, 0, SYMTYPE); + else + symlink_error (current_stat_info.link_name, file_name); return status; #else @@ -1180,11 +1197,11 @@ extract_archive (void) /* Extract the symbolic links whose final extraction were delayed. */ static void -apply_delayed_symlinks (void) +apply_delayed_links (void) { - struct delayed_symlink *ds; + struct delayed_link *ds; - for (ds = delayed_symlink_head; ds; ) + for (ds = delayed_link_head; ds; ) { struct string_list *sources = ds->sources; char const *valid_source = 0; @@ -1195,7 +1212,7 @@ apply_delayed_symlinks (void) struct stat st; /* Make sure the placeholder file is still there. If not, - don't create a symlink, as the placeholder was probably + don't create a link, as the placeholder was probably removed by a later extraction. */ if (lstat (source, &st) == 0 && st.st_dev == ds->dev @@ -1208,6 +1225,11 @@ apply_delayed_symlinks (void) unlink_error (source); else if (valid_source && link (valid_source, source) == 0) ; + else if (!ds->is_symlink) + { + if (link (ds->target, source) != 0) + link_error (ds->target, source); + } else if (symlink (ds->target, source) != 0) symlink_error (ds->target, source); else @@ -1228,13 +1250,13 @@ apply_delayed_symlinks (void) } { - struct delayed_symlink *next = ds->next; + struct delayed_link *next = ds->next; free (ds); ds = next; } } - delayed_symlink_head = 0; + delayed_link_head = 0; } /* Finish the extraction of an archive. */ @@ -1244,12 +1266,12 @@ extract_finish (void) /* First, fix the status of ordinary directories that need fixing. */ apply_nonancestor_delayed_set_stat ("", 0); - /* Then, apply delayed symlinks, so that they don't affect delayed + /* Then, apply delayed links, so that they don't affect delayed directory status-setting for ordinary directories. */ - apply_delayed_symlinks (); + apply_delayed_links (); /* Finally, fix the status of directories that are ancestors - of delayed symlinks. */ + of delayed links. */ apply_nonancestor_delayed_set_stat ("", 1); }