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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-04 12:43:57 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-04 13:42:06 +0200
commit6623b1fe4df1e2fceb27eff286a86cf36809b2bc (patch)
tree95dce50157ca3f79e3fdcfae901a124660f20e93 /lib/tar
parent56c1be44b5f77b067994a6f8f6ef2b397d7acadc (diff)
libtar: add support for xattr extensions
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/tar')
-rw-r--r--lib/tar/base64.c33
-rw-r--r--lib/tar/cleanup.c12
-rw-r--r--lib/tar/internal.h6
-rw-r--r--lib/tar/read_header.c52
-rw-r--r--lib/tar/urldecode.c31
5 files changed, 133 insertions, 1 deletions
diff --git a/lib/tar/base64.c b/lib/tar/base64.c
new file mode 100644
index 0000000..313e9f4
--- /dev/null
+++ b/lib/tar/base64.c
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "internal.h"
+
+static uint8_t convert(char in)
+{
+ if (isupper(in))
+ return in - 'A';
+ if (islower(in))
+ return in - 'a' + 26;
+ if (isdigit(in))
+ return in - '0' + 52;
+ if (in == '+')
+ return 62;
+ if (in == '/' || in == '-')
+ return 63;
+ return 0;
+}
+
+void base64_decode(uint8_t *out, const char *in)
+{
+ char temp[4];
+
+ while (*in != '\0' && *in != '=') {
+ temp[0] = *in == '\0' ? 0 : convert(*(in++));
+ temp[1] = *in == '\0' ? 0 : convert(*(in++));
+ temp[2] = *in == '\0' ? 0 : convert(*(in++));
+ temp[3] = *in == '\0' ? 0 : convert(*(in++));
+
+ *(out++) = ((temp[0] << 2) & 0xFC) | ((temp[1] >> 4) & 0x03);
+ *(out++) = ((temp[1] << 4) & 0xF0) | ((temp[2] >> 2) & 0x0F);
+ *(out++) = ((temp[2] << 6) & 0xC0) | ( temp[3] & 0x3F);
+ }
+}
diff --git a/lib/tar/cleanup.c b/lib/tar/cleanup.c
index c4d1734..a34c28b 100644
--- a/lib/tar/cleanup.c
+++ b/lib/tar/cleanup.c
@@ -12,8 +12,20 @@ void free_sparse_list(sparse_map_t *sparse)
}
}
+void free_xattr_list(tar_xattr_t *list)
+{
+ tar_xattr_t *old;
+
+ while (list != NULL) {
+ old = list;
+ list = list->next;
+ free(old);
+ }
+}
+
void clear_header(tar_header_decoded_t *hdr)
{
+ free_xattr_list(hdr->xattr);
free_sparse_list(hdr->sparse);
free(hdr->name);
free(hdr->link_target);
diff --git a/lib/tar/internal.h b/lib/tar/internal.h
index 3c0e27f..04a97d3 100644
--- a/lib/tar/internal.h
+++ b/lib/tar/internal.h
@@ -50,4 +50,10 @@ sparse_map_t *read_gnu_old_sparse(int fd, tar_header_t *hdr);
void free_sparse_list(sparse_map_t *sparse);
+void free_xattr_list(tar_xattr_t *list);
+
+void base64_decode(uint8_t *out, const char *in);
+
+void urldecode(char *str);
+
#endif /* INTERNAL_H */
diff --git a/lib/tar/read_header.c b/lib/tar/read_header.c
index db40d7d..94c4a69 100644
--- a/lib/tar/read_header.c
+++ b/lib/tar/read_header.c
@@ -60,12 +60,29 @@ fail:
return NULL;
}
+static tar_xattr_t *mkxattr(const char *key, size_t keylen,
+ const char *value, size_t valuelen)
+{
+ tar_xattr_t *xattr;
+
+ xattr = calloc(1, sizeof(*xattr) + keylen + 1 + valuelen + 1);
+ if (xattr == NULL)
+ return NULL;
+
+ xattr->key = xattr->data;
+ xattr->value = xattr->data + keylen + 1;
+ memcpy(xattr->key, key, keylen);
+ memcpy(xattr->value, value, valuelen);
+ return xattr;
+}
+
static int read_pax_header(int fd, uint64_t entsize, unsigned int *set_by_pax,
tar_header_decoded_t *out)
{
sparse_map_t *sparse_last = NULL, *sparse;
uint64_t field, offset = 0, num_bytes = 0;
- char *buffer, *line;
+ char *buffer, *line, *key, *ptr, *value;
+ tar_xattr_t *xattr;
uint64_t i;
buffer = record_to_memory(fd, entsize);
@@ -183,6 +200,39 @@ static int read_pax_header(int fd, uint64_t entsize, unsigned int *set_by_pax,
sparse_last->next = sparse;
sparse_last = sparse;
}
+ } else if (!strncmp(line, "SCHILY.xattr.", 13)) {
+ key = line + 13;
+
+ ptr = strrchr(key, '=');
+ if (ptr == NULL || ptr == key)
+ continue;
+
+ value = ptr + 1;
+
+ xattr = mkxattr(key, ptr - key, value, strlen(value));
+ if (xattr == NULL)
+ goto fail_errno;
+
+ xattr->next = out->xattr;
+ out->xattr = xattr;
+ } else if (!strncmp(line, "LIBARCHIVE.xattr.", 17)) {
+ key = line + 17;
+
+ ptr = strrchr(key, '=');
+ if (ptr == NULL || ptr == key)
+ continue;
+
+ value = ptr + 1;
+
+ xattr = mkxattr(key, ptr - key, value, strlen(value));
+ if (xattr == NULL)
+ goto fail_errno;
+
+ urldecode(xattr->key);
+ base64_decode((uint8_t *)xattr->value, value);
+
+ xattr->next = out->xattr;
+ out->xattr = xattr;
}
}
diff --git a/lib/tar/urldecode.c b/lib/tar/urldecode.c
new file mode 100644
index 0000000..ac03f10
--- /dev/null
+++ b/lib/tar/urldecode.c
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "internal.h"
+
+static int xdigit(int x)
+{
+ if (isupper(x))
+ return x - 'A' + 0x0A;
+ if (islower(x))
+ return x - 'a' + 0x0A;
+ return x - '0';
+}
+
+void urldecode(char *str)
+{
+ unsigned char *out = (unsigned char *)str;
+ char *in = str;
+ int x;
+
+ while (*in != '\0') {
+ x = *(in++);
+
+ if (x == '%' && isxdigit(in[0]) && isxdigit(in[1])) {
+ x = xdigit(*(in++)) << 4;
+ x |= xdigit(*(in++));
+ }
+
+ *(out++) = x;
+ }
+
+ *out = '\0';
+}