diff options
Diffstat (limited to 'archival/libarchive/get_header_ar.c')
| -rw-r--r-- | archival/libarchive/get_header_ar.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/archival/libarchive/get_header_ar.c b/archival/libarchive/get_header_ar.c new file mode 100644 index 0000000..df603b1 --- /dev/null +++ b/archival/libarchive/get_header_ar.c @@ -0,0 +1,133 @@ +/* vi: set sw=4 ts=4: */ +/* Copyright 2001 Glenn McGrath. + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + */ + +#include "libbb.h" +#include "archive.h" +#include "ar.h" + +static unsigned read_num(const char *str, int base) +{ + /* This code works because + * on misformatted numbers bb_strtou returns all-ones */ + int err = bb_strtou(str, NULL, base); + if (err == -1) + bb_error_msg_and_die("invalid ar header"); + return err; +} + +char FAST_FUNC get_header_ar(archive_handle_t *archive_handle) +{ + file_header_t *typed = archive_handle->file_header; + unsigned size; + union { + char raw[60]; + struct ar_header formatted; + } ar; +#if ENABLE_FEATURE_AR_LONG_FILENAMES + static char *ar_long_names; + static unsigned ar_long_name_size; +#endif + + /* dont use xread as we want to handle the error ourself */ + if (read(archive_handle->src_fd, ar.raw, 60) != 60) { + /* End Of File */ + return EXIT_FAILURE; + } + + /* ar header starts on an even byte (2 byte aligned) + * '\n' is used for padding + */ + if (ar.raw[0] == '\n') { + /* fix up the header, we started reading 1 byte too early */ + memmove(ar.raw, &ar.raw[1], 59); + ar.raw[59] = xread_char(archive_handle->src_fd); + archive_handle->offset++; + } + archive_handle->offset += 60; + + if (ar.formatted.magic[0] != '`' || ar.formatted.magic[1] != '\n') + bb_error_msg_and_die("invalid ar header"); + + /* FIXME: more thorough routine would be in order here + * (we have something like that in tar) + * but for now we are lax. */ + ar.formatted.magic[0] = '\0'; /* else 4G-2 file will have size="4294967294`\n..." */ + typed->size = size = read_num(ar.formatted.size, 10); + + /* special filenames have '/' as the first character */ + if (ar.formatted.name[0] == '/') { + if (ar.formatted.name[1] == ' ') { + /* This is the index of symbols in the file for compilers */ + data_skip(archive_handle); + archive_handle->offset += size; + return get_header_ar(archive_handle); /* Return next header */ + } +#if ENABLE_FEATURE_AR_LONG_FILENAMES + if (ar.formatted.name[1] == '/') { + /* If the second char is a '/' then this entries data section + * stores long filename for multiple entries, they are stored + * in static variable long_names for use in future entries + */ + ar_long_name_size = size; + free(ar_long_names); + ar_long_names = xmalloc(size); + xread(archive_handle->src_fd, ar_long_names, size); + archive_handle->offset += size; + /* Return next header */ + return get_header_ar(archive_handle); + } +#else + bb_error_msg_and_die("long filenames not supported"); +#endif + } + /* Only size is always present, the rest may be missing in + * long filename pseudo file. Thus we decode the rest + * after dealing with long filename pseudo file. + */ + typed->mode = read_num(ar.formatted.mode, 8); + typed->mtime = read_num(ar.formatted.date, 10); + typed->uid = read_num(ar.formatted.uid, 10); + typed->gid = read_num(ar.formatted.gid, 10); + +#if ENABLE_FEATURE_AR_LONG_FILENAMES + if (ar.formatted.name[0] == '/') { + unsigned long_offset; + + /* The number after the '/' indicates the offset in the ar data section + * (saved in ar_long_names) that conatains the real filename */ + long_offset = read_num(&ar.formatted.name[1], 10); + if (long_offset >= ar_long_name_size) { + bb_error_msg_and_die("can't resolve long filename"); + } + typed->name = xstrdup(ar_long_names + long_offset); + } else +#endif + { + /* short filenames */ + typed->name = xstrndup(ar.formatted.name, 16); + } + + typed->name[strcspn(typed->name, " /")] = '\0'; + + if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) { + archive_handle->action_header(typed); +#if ENABLE_DPKG || ENABLE_DPKG_DEB + if (archive_handle->dpkg__sub_archive) { + while (archive_handle->dpkg__action_data_subarchive(archive_handle->dpkg__sub_archive) == EXIT_SUCCESS) + continue; + } else +#endif + archive_handle->action_data(archive_handle); + } else { + data_skip(archive_handle); + } + + archive_handle->offset += typed->size; + /* Set the file pointer to the correct spot, we may have been reading a compressed file */ + lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET); + + return EXIT_SUCCESS; +} |