diff options
Diffstat (limited to 'libtar/block.c')
| -rw-r--r-- | libtar/block.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/libtar/block.c b/libtar/block.c index 89e5e3d70..1cfc0e418 100644 --- a/libtar/block.c +++ b/libtar/block.c @@ -21,6 +21,10 @@ #define BIT_ISSET(bitmask, bit) ((bitmask) & (bit)) +// Used to identify selinux_context in extended ('x') +// metadata. From RedHat implementation. +#define SELINUX_TAG "RHT.security.selinux=" +#define SELINUX_TAG_LEN 21 /* read a header block */ int @@ -101,6 +105,11 @@ th_read(TAR *t) free(t->th_buf.gnu_longname); if (t->th_buf.gnu_longlink != NULL) free(t->th_buf.gnu_longlink); +#ifdef HAVE_SELINUX + if (t->th_buf.selinux_context != NULL) + free(t->th_buf.selinux_context); +#endif + memset(&(t->th_buf), 0, sizeof(struct tar_header)); i = th_read_internal(t); @@ -203,6 +212,57 @@ th_read(TAR *t) } } +#ifdef HAVE_SELINUX + if(TH_ISEXTHEADER(t)) + { + sz = th_get_size(t); + + if(sz >= T_BLOCKSIZE) // Not supported + { +#ifdef DEBUG + printf(" th_read(): Extended header is too long!\n"); +#endif + } + else + { + char buf[T_BLOCKSIZE]; + i = tar_block_read(t, buf); + if (i != T_BLOCKSIZE) + { + if (i != -1) + errno = EINVAL; + return -1; + } + + // To be sure + buf[T_BLOCKSIZE-1] = 0; + + int len = strlen(buf); + char *start = strstr(buf, SELINUX_TAG); + if(start && start+SELINUX_TAG_LEN < buf+len) + { + start += SELINUX_TAG_LEN; + char *end = strchr(start, '\n'); + if(end) + { + t->th_buf.selinux_context = strndup(start, end-start); +#ifdef DEBUG + printf(" th_read(): SELinux context xattr detected: %s\n", t->th_buf.selinux_context); +#endif + } + } + } + + i = th_read_internal(t); + if (i != T_BLOCKSIZE) + { + if (i != -1) + errno = EINVAL; + return -1; + } + } +#endif + #if 0 /* ** work-around for old archive files with broken typeflag fields @@ -359,6 +419,59 @@ th_write(TAR *t) th_set_size(t, sz2); } +#ifdef HAVE_SELINUX + if((t->options & TAR_STORE_SELINUX) && t->th_buf.selinux_context != NULL) + { +#ifdef DEBUG + printf("th_write(): using selinux_context (\"%s\")\n", + t->th_buf.selinux_context); +#endif + /* save old size and type */ + type2 = t->th_buf.typeflag; + sz2 = th_get_size(t); + + /* write out initial header block with fake size and type */ + t->th_buf.typeflag = TH_EXT_TYPE; + + /* setup size - EXT header has format "*size of this whole tag as ascii numbers* *space* *content* *newline* */ + // size newline + sz = SELINUX_TAG_LEN + strlen(t->th_buf.selinux_context) + 3 + 1; + + if(sz >= 100) // another ascci digit for size + ++sz; + + if(sz >= T_BLOCKSIZE) // impossible + { + errno = EINVAL; + return -1; + } + + th_set_size(t, sz); + th_finish(t); + i = tar_block_write(t, &(t->th_buf)); + if (i != T_BLOCKSIZE) + { + if (i != -1) + errno = EINVAL; + return -1; + } + + memset(buf, 0, T_BLOCKSIZE); + snprintf(buf, T_BLOCKSIZE, "%d "SELINUX_TAG"%s\n", sz, t->th_buf.selinux_context); + i = tar_block_write(t, &buf); + if (i != T_BLOCKSIZE) + { + if (i != -1) + errno = EINVAL; + return -1; + } + + /* reset type and size to original values */ + t->th_buf.typeflag = type2; + th_set_size(t, sz2); + } +#endif + th_finish(t); #ifdef DEBUG |