unzip: fix endianness bugs
authorDenis Vlasenko <vda.linux@googlemail.com>
Thu, 18 Oct 2007 23:27:46 +0000 (23:27 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Thu, 18 Oct 2007 23:27:46 +0000 (23:27 -0000)
archival/unzip.c

index bd113af208f2719d4510778dd021ecdeb32ba396..37781e44e4a7d03fea49c21cc5a64316a24e515e 100644 (file)
 #include "libbb.h"
 #include "unarchive.h"
 
-#define ZIP_FILEHEADER_MAGIC           SWAP_LE32(0x04034b50)
-#define ZIP_CDS_MAGIC                  SWAP_LE32(0x02014b50)
-#define ZIP_CDS_END_MAGIC              SWAP_LE32(0x06054b50)
-#define ZIP_DD_MAGIC                   SWAP_LE32(0x08074b50)
+enum {
+#if BB_BIG_ENDIAN
+       ZIP_FILEHEADER_MAGIC = 0x504b0304,
+       ZIP_CDS_MAGIC        = 0x504b0102,
+       ZIP_CDS_END_MAGIC    = 0x504b0506,
+       ZIP_DD_MAGIC         = 0x504b0708,
+#else
+       ZIP_FILEHEADER_MAGIC = 0x04034b50,
+       ZIP_CDS_MAGIC        = 0x02014b50,
+       ZIP_CDS_END_MAGIC    = 0x06054b50,
+       ZIP_DD_MAGIC         = 0x08074b50,
+#endif
+};
 
 typedef union {
-       unsigned char raw[26];
+       uint8_t raw[26];
        struct {
-               unsigned short version; /* 0-1 */
-               unsigned short flags;   /* 2-3 */
-               unsigned short method;  /* 4-5 */
-               unsigned short modtime; /* 6-7 */
-               unsigned short moddate; /* 8-9 */
-               unsigned int crc32 ATTRIBUTE_PACKED;    /* 10-13 */
-               unsigned int cmpsize ATTRIBUTE_PACKED;  /* 14-17 */
-               unsigned int ucmpsize ATTRIBUTE_PACKED; /* 18-21 */
-               unsigned short filename_len;    /* 22-23 */
-               unsigned short extra_len;               /* 24-25 */
+               uint16_t version;                       /* 0-1 */
+               uint16_t flags;                         /* 2-3 */
+               uint16_t method;                        /* 4-5 */
+               uint16_t modtime;                       /* 6-7 */
+               uint16_t moddate;                       /* 8-9 */
+               uint32_t crc32 ATTRIBUTE_PACKED;        /* 10-13 */
+               uint32_t cmpsize ATTRIBUTE_PACKED;      /* 14-17 */
+               uint32_t ucmpsize ATTRIBUTE_PACKED;     /* 18-21 */
+               uint16_t filename_len;                  /* 22-23 */
+               uint16_t extra_len;                     /* 24-25 */
        } formatted ATTRIBUTE_PACKED;
 } zip_header_t;
 
+struct BUG_zip_header_must_be_26_bytes {
+       char BUG_zip_header_must_be_26_bytes[sizeof(zip_header_t) == 26 ? 1 : -1];
+};
+
+#define FIX_ENDIANNESS(zip_header) do { \
+       (zip_header).formatted.version      = SWAP_LE16((zip_header).formatted.version     ); \
+       (zip_header).formatted.flags        = SWAP_LE16((zip_header).formatted.flags       ); \
+       (zip_header).formatted.method       = SWAP_LE16((zip_header).formatted.method      ); \
+       (zip_header).formatted.modtime      = SWAP_LE16((zip_header).formatted.modtime     ); \
+       (zip_header).formatted.moddate      = SWAP_LE16((zip_header).formatted.moddate     ); \
+       (zip_header).formatted.crc32        = SWAP_LE32((zip_header).formatted.crc32       ); \
+       (zip_header).formatted.cmpsize      = SWAP_LE32((zip_header).formatted.cmpsize     ); \
+       (zip_header).formatted.ucmpsize     = SWAP_LE32((zip_header).formatted.ucmpsize    ); \
+       (zip_header).formatted.filename_len = SWAP_LE16((zip_header).formatted.filename_len); \
+       (zip_header).formatted.extra_len    = SWAP_LE16((zip_header).formatted.extra_len   ); \
+} while (0)
+
 static void unzip_skip(int fd, off_t skip)
 {
-       if (lseek(fd, skip, SEEK_CUR) == (off_t)-1) {
-               if (errno != ESPIPE)
-                       bb_error_msg_and_die("seek failure");
-               bb_copyfd_exact_size(fd, -1, skip);
-       }
+       bb_copyfd_exact_size(fd, -1, skip);
 }
 
-static void unzip_create_leading_dirs(char *fn)
+static void unzip_create_leading_dirs(const char *fn)
 {
        /* Create all leading directories */
        char *name = xstrdup(fn);
@@ -67,7 +89,7 @@ static void unzip_create_leading_dirs(char *fn)
        free(name);
 }
 
-static int unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
+static void unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
 {
        if (zip_header->formatted.method == 0) {
                /* Method 0 - stored (not compressed) */
@@ -77,42 +99,43 @@ static int unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
        } else {
                /* Method 8 - inflate */
                inflate_unzip_result res;
-               /* err = */ inflate_unzip(&res, zip_header->formatted.cmpsize, src_fd, dst_fd);
-// we should check for -1 error return
+               if (inflate_unzip(&res, zip_header->formatted.cmpsize, src_fd, dst_fd) < 0)
+                       bb_error_msg_and_die("inflate error");
                /* Validate decompression - crc */
                if (zip_header->formatted.crc32 != (res.crc ^ 0xffffffffL)) {
-                       bb_error_msg("invalid compressed data--%s error", "crc");
-                       return 1;
+                       bb_error_msg_and_die("crc error");
                }
                /* Validate decompression - size */
                if (zip_header->formatted.ucmpsize != res.bytes_out) {
-                       bb_error_msg("invalid compressed data--%s error", "length");
-                       return 1;
+                       bb_error_msg("bad length");
                }
        }
-       return 0;
 }
 
 int unzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int unzip_main(int argc, char **argv)
 {
+       enum { O_PROMPT, O_NEVER, O_ALWAYS };
+
        zip_header_t zip_header;
        smallint verbose = 1;
        smallint listing = 0;
-       smallint list_header_done = 0;
-       smallint failed;
-       enum {o_prompt, o_never, o_always} overwrite = o_prompt;
-       unsigned int total_size = 0;
-       unsigned int total_entries = 0;
-       int src_fd = -1, dst_fd = -1;
-       char *src_fn = NULL, *dst_fn = NULL;
+       smallint overwrite = O_PROMPT;
+       unsigned total_size;
+       unsigned total_entries;
+       int src_fd = -1;
+       int dst_fd = -1;
+       char *src_fn = NULL;
+       char *dst_fn = NULL;
        llist_t *zaccept = NULL;
        llist_t *zreject = NULL;
        char *base_dir = NULL;
-       int i, opt, opt_range = 0;
-       char key_buf[512];
+       int i, opt;
+       int opt_range = 0;
+       char key_buf[80];
        struct stat stat_buf;
 
+       /* '-' makes getopt return 1 for non-options */
        while ((opt = getopt(argc, argv, "-d:lnopqx")) != -1) {
                switch (opt_range) {
                case 0: /* Options */
@@ -122,11 +145,11 @@ int unzip_main(int argc, char **argv)
                                break;
 
                        case 'n': /* Never overwrite existing files */
-                               overwrite = o_never;
+                               overwrite = O_NEVER;
                                break;
 
                        case 'o': /* Always overwrite existing files */
-                               overwrite = o_always;
+                               overwrite = O_ALWAYS;
                                break;
 
                        case 'p': /* Extract files to stdout and fall through to set verbosity */
@@ -136,8 +159,9 @@ int unzip_main(int argc, char **argv)
                                verbose = 0;
                                break;
 
-                       case 1 : /* The zip file */
-                               src_fn = xmalloc(strlen(optarg)+4);
+                       case 1: /* The zip file */
+                               /* +5: space for ".zip" and NUL */
+                               src_fn = xmalloc(strlen(optarg) + 5);
                                strcpy(src_fn, optarg);
                                opt_range++;
                                break;
@@ -151,31 +175,30 @@ int unzip_main(int argc, char **argv)
                case 1: /* Include files */
                        if (opt == 1) {
                                llist_add_to(&zaccept, optarg);
-
-                       } else if (opt == 'd') {
+                               break;
+                       }
+                       if (opt == 'd') {
                                base_dir = optarg;
                                opt_range += 2;
-
-                       } else if (opt == 'x') {
+                               break;
+                       }
+                       if (opt == 'x') {
                                opt_range++;
-
-                       } else {
-                               bb_show_usage();
+                               break;
                        }
-                       break;
+                       bb_show_usage();
 
                case 2 : /* Exclude files */
                        if (opt == 1) {
                                llist_add_to(&zreject, optarg);
-
-                       } else if (opt == 'd') { /* Extract to base directory */
+                               break;
+                       }
+                       if (opt == 'd') { /* Extract to base directory */
                                base_dir = optarg;
                                opt_range++;
-
-                       } else {
-                               bb_show_usage();
+                               break;
                        }
-                       break;
+                       /* fall through */
 
                default:
                        bb_show_usage();
@@ -190,17 +213,19 @@ int unzip_main(int argc, char **argv)
        if (LONE_DASH(src_fn)) {
                src_fd = STDIN_FILENO;
                /* Cannot use prompt mode since zip data is arriving on STDIN */
-               overwrite = (overwrite == o_prompt) ? o_never : overwrite;
+               if (overwrite == O_PROMPT)
+                       overwrite = O_NEVER;
        } else {
-               static const char *const extn[] = {"", ".zip", ".ZIP"};
+               static const char extn[][5] = {"", ".zip", ".ZIP"};
                int orig_src_fn_len = strlen(src_fn);
+
                for (i = 0; (i < 3) && (src_fd == -1); i++) {
                        strcpy(src_fn + orig_src_fn_len, extn[i]);
                        src_fd = open(src_fn, O_RDONLY);
                }
                if (src_fd == -1) {
                        src_fn[orig_src_fn_len] = '\0';
-                       bb_error_msg_and_die("cannot open %s, %s.zip, %s.ZIP", src_fn, src_fn, src_fn);
+                       bb_error_msg_and_die("can't open %s, %s.zip, %s.ZIP", src_fn, src_fn, src_fn);
                }
        }
 
@@ -208,36 +233,31 @@ int unzip_main(int argc, char **argv)
        if (base_dir)
                xchdir(base_dir);
 
-       if (verbose)
+       if (verbose) {
                printf("Archive:  %s\n", src_fn);
+               if (listing){
+                       puts("  Length     Date   Time    Name\n"
+                            " --------    ----   ----    ----");
+               }
+       }
 
-       failed = 0;
-
+       total_size = 0;
+       total_entries = 0;
        while (1) {
-               unsigned int magic;
+               uint32_t magic;
 
                /* Check magic number */
                xread(src_fd, &magic, 4);
-               if (magic == ZIP_CDS_MAGIC) {
+               if (magic == ZIP_CDS_MAGIC)
                        break;
-               } else if (magic != ZIP_FILEHEADER_MAGIC) {
+               if (magic != ZIP_FILEHEADER_MAGIC)
                        bb_error_msg_and_die("invalid zip magic %08X", magic);
-               }
 
                /* Read the file header */
-               xread(src_fd, zip_header.raw, 26);
-               zip_header.formatted.version = SWAP_LE32(zip_header.formatted.version);
-               zip_header.formatted.flags = SWAP_LE32(zip_header.formatted.flags);
-               zip_header.formatted.method = SWAP_LE32(zip_header.formatted.method);
-               zip_header.formatted.modtime = SWAP_LE32(zip_header.formatted.modtime);
-               zip_header.formatted.moddate = SWAP_LE32(zip_header.formatted.moddate);
-               zip_header.formatted.crc32 = SWAP_LE32(zip_header.formatted.crc32);
-               zip_header.formatted.cmpsize = SWAP_LE32(zip_header.formatted.cmpsize);
-               zip_header.formatted.ucmpsize = SWAP_LE32(zip_header.formatted.ucmpsize);
-               zip_header.formatted.filename_len = SWAP_LE32(zip_header.formatted.filename_len);
-               zip_header.formatted.extra_len = SWAP_LE32(zip_header.formatted.extra_len);
+               xread(src_fd, zip_header.raw, sizeof(zip_header));
+               FIX_ENDIANNESS(zip_header);
                if ((zip_header.formatted.method != 0) && (zip_header.formatted.method != 8)) {
-                       bb_error_msg_and_die("unsupported compression method %d", zip_header.formatted.method);
+                       bb_error_msg_and_die("unsupported method %d", zip_header.formatted.method);
                }
 
                /* Read filename */
@@ -248,23 +268,16 @@ int unzip_main(int argc, char **argv)
                /* Skip extra header bytes */
                unzip_skip(src_fd, zip_header.formatted.extra_len);
 
-               if (listing && verbose && !list_header_done){
-                       puts("  Length     Date   Time    Name\n"
-                            " --------    ----   ----    ----");
-                       list_header_done = 1;
-               }
-
                /* Filter zip entries */
-               if (find_list_entry(zreject, dst_fn) ||
-                       (zaccept && !find_list_entry(zaccept, dst_fn))) { /* Skip entry */
+               if (find_list_entry(zreject, dst_fn)
+                || (zaccept && !find_list_entry(zaccept, dst_fn))
+               ) { /* Skip entry */
                        i = 'n';
 
                } else { /* Extract entry */
-                       total_size += zip_header.formatted.ucmpsize;
-
                        if (listing) { /* List entry */
                                if (verbose) {
-                                       unsigned int dostime = zip_header.formatted.modtime | (zip_header.formatted.moddate << 16);
+                                       unsigned dostime = zip_header.formatted.modtime | (zip_header.formatted.moddate << 16);
                                        printf("%9u  %02u-%02u-%02u %02u:%02u   %s\n",
                                           zip_header.formatted.ucmpsize,
                                           (dostime & 0x01e00000) >> 21,
@@ -273,6 +286,7 @@ int unzip_main(int argc, char **argv)
                                           (dostime & 0x0000f800) >> 11,
                                           (dostime & 0x000007e0) >> 5,
                                           dst_fn);
+                                       total_size += zip_header.formatted.ucmpsize;
                                        total_entries++;
                                } else {
                                        /* short listing -- filenames only */
@@ -308,14 +322,14 @@ int unzip_main(int argc, char **argv)
                                        }
                                        i = 'y';
                                } else { /* File already exists */
-                                       if (overwrite == o_never) {
+                                       if (overwrite == O_NEVER) {
                                                i = 'n';
                                        } else if (S_ISREG(stat_buf.st_mode)) { /* File is regular file */
-                                               if (overwrite == o_always) {
+                                               if (overwrite == O_ALWAYS) {
                                                        i = 'y';
                                                } else {
                                                        printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
-                                                       if (!fgets(key_buf, 512, stdin)) {
+                                                       if (!fgets(key_buf, sizeof(key_buf), stdin)) {
                                                                bb_perror_msg_and_die("cannot read input");
                                                        }
                                                        i = key_buf[0];
@@ -329,7 +343,7 @@ int unzip_main(int argc, char **argv)
 
                switch (i) {
                case 'A':
-                       overwrite = o_always;
+                       overwrite = O_ALWAYS;
                case 'y': /* Open file and fall into unzip */
                        unzip_create_leading_dirs(dst_fn);
                        dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC);
@@ -337,9 +351,7 @@ int unzip_main(int argc, char **argv)
                        if (verbose) {
                                printf("  inflating: %s\n", dst_fn);
                        }
-                       if (unzip_extract(&zip_header, src_fd, dst_fd)) {
-                               failed = 1;
-                       }
+                       unzip_extract(&zip_header, src_fd, dst_fd);
                        if (dst_fd != STDOUT_FILENO) {
                                /* closing STDOUT is potentially bad for future business */
                                close(dst_fd);
@@ -347,7 +359,7 @@ int unzip_main(int argc, char **argv)
                        break;
 
                case 'N':
-                       overwrite = o_never;
+                       overwrite = O_NEVER;
                case 'n':
                        /* Skip entry data */
                        unzip_skip(src_fd, zip_header.formatted.cmpsize);
@@ -356,7 +368,7 @@ int unzip_main(int argc, char **argv)
                case 'r':
                        /* Prompt for new name */
                        printf("new name: ");
-                       if (!fgets(key_buf, 512, stdin)) {
+                       if (!fgets(key_buf, sizeof(key_buf), stdin)) {
                                bb_perror_msg_and_die("cannot read input");
                        }
                        free(dst_fn);
@@ -378,8 +390,9 @@ int unzip_main(int argc, char **argv)
 
        if (listing && verbose) {
                printf(" --------                   -------\n"
-                      "%9d                   %d files\n", total_size, total_entries);
+                      "%9d                   %d files\n",
+                      total_size, total_entries);
        }
 
-       return failed;
+       return 0;
 }