Move get_ar_headers to libbb, make dpkg_deb.c independent of ar.c

2 files changed, 130 insertions, 0 deletions

diff --git a/libbb/get_ar_headers.c b/libbb/get_ar_headers.c
new file mode 100644
index 000000000..cf7de5c2a
--- /dev/null
+++ b/libbb/get_ar_headers.c
@@ -0,0 +1,118 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) tons of folks.  Tracking down who wrote what
+ * isn't something I'm going to worry about...  If you wrote something
+ * here, please feel free to acknowledge your work.
+ *
+ * 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 Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
+ * Permission has been granted to redistribute this code under the GPL.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "libbb.h"
+
+extern ar_headers_t get_ar_headers(int srcFd)
+{
+        typedef struct raw_ar_header_s {        /* Byte Offset */
+                char name[16];  /*  0-15 */
+                char date[12];  /* 16-27 */
+                char uid[6];    
+                char gid[6];    /* 28-39 */
+                char mode[8];   /* 40-47 */
+                char size[10];  /* 48-57 */
+                char fmag[2];   /* 58-59 */
+        } raw_ar_header_t;
+
+        raw_ar_header_t raw_ar_header;
+
+        ar_headers_t *head, *entry;
+        char ar_magic[8];
+        char *long_name=NULL;
+        
+        head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+        entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+        
+        /* check ar magic */
+        if (full_read(srcFd, ar_magic, 8) != 8) {
+                error_msg_and_die("cannot read magic");
+        }
+
+        if (strncmp(ar_magic,"!<arch>",7) != 0) {
+                error_msg_and_die("invalid magic");
+        }
+
+        while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
+                /* check the end of header markers are valid */
+                if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
+                        char newline;
+                        if (raw_ar_header.fmag[1]!='`') {
+                                break;
+                        }
+                        /* some version of ar, have an extra '\n' after each entry */
+                        read(srcFd, &newline, 1);
+                        if (newline!='\n') {
+                                break;
+                        }
+                        /* fix up the header, we started reading 1 byte too early due to a '\n' */
+                        memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
+                        /* dont worry about adding the last '\n', we dont need it now */
+                }
+                
+                entry->size = (off_t) atoi(raw_ar_header.size);
+                /* long filenames have '/' as the first character */
+                if (raw_ar_header.name[0] == '/') {
+                        if (raw_ar_header.name[1] == '/') {
+                                /* multiple long filenames are stored as data in one entry */
+                                long_name = (char *) xrealloc(long_name, entry->size);
+                                full_read(srcFd, long_name, entry->size);
+                                continue;
+                        }
+                        else {
+                                /* The number after the '/' indicates the offset in the ar data section
+                                        (saved in variable long_name) that conatains the real filename */
+                                const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
+                                entry->name = xmalloc(strlen(&long_name[long_name_offset]));
+                                strcpy(entry->name, &long_name[long_name_offset]);
+                        }
+                }
+                else {
+                        /* short filenames */
+                        entry->name = xmalloc(16);
+                        strncpy(entry->name, raw_ar_header.name, 16);
+                }
+                entry->name[strcspn(entry->name, " /")]='\0';
+
+                /* convert the rest of the now valid char header to its typed struct */ 
+                parse_mode(raw_ar_header.mode, &entry->mode);
+                entry->mtime = atoi(raw_ar_header.date);
+                entry->uid = atoi(raw_ar_header.uid);
+                entry->gid = atoi(raw_ar_header.gid);
+                entry->offset = lseek(srcFd, 0, SEEK_CUR);
+
+                /* add this entries header to our combined list */
+                entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
+                *entry->next = *head;
+                *head = *entry;
+                lseek(srcFd, (off_t) entry->size, SEEK_CUR);
+        }
+        return(*head);
+}
\ No newline at end of file
diff --git a/libbb/libbb.h b/libbb/libbb.h
index 6133b19d3..649fe11c1 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -215,4 +215,16 @@ int klogctl(int type, char * b, int len);
 char *xgetcwd(char *cwd);
 char *concat_path_file(const char *path, const char *filename);
 
+typedef struct ar_headers_s {
+        char *name;
+        off_t size;
+        uid_t uid;
+        gid_t gid;
+        mode_t mode;
+        time_t mtime;
+        off_t offset;
+        struct ar_headers_s *next;
+} ar_headers_t;
+extern ar_headers_t get_ar_headers(int srcFd);
+
 #endif /* __LIBBB_H__ */