tag.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "commit.h"
   4 #include "tree.h"
   5 #include "blob.h"
   6
   7 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
   8 #define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
   9
  10 const char *tag_type = "tag";
  11
  12 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
  13 {
  14         while (o && o->type == OBJ_TAG)
  15                 if (((struct tag *)o)->tagged)
  16                         o = parse_object(((struct tag *)o)->tagged->sha1);
  17                 else
  18                         o = NULL;
  19         if (!o && warn) {
  20                 if (!warnlen)
  21                         warnlen = strlen(warn);
  22                 error("missing object referenced by '%.*s'", warnlen, warn);
  23         }
  24         return o;
  25 }
  26
  27 struct object *deref_tag_noverify(struct object *o)
  28 {
  29         while (o && o->type == OBJ_TAG) {
  30                 o = parse_object(o->sha1);
  31                 if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
  32                         o = ((struct tag *)o)->tagged;
  33                 else
  34                         o = NULL;
  35         }
  36         return o;
  37 }
  38
  39 struct tag *lookup_tag(const unsigned char *sha1)
  40 {
  41         struct object *obj = lookup_object(sha1);
  42         if (!obj)
  43                 return create_object(sha1, OBJ_TAG, alloc_tag_node());
  44         if (!obj->type)
  45                 obj->type = OBJ_TAG;
  46         if (obj->type != OBJ_TAG) {
  47                 error("Object %s is a %s, not a tag",
  48                       sha1_to_hex(sha1), typename(obj->type));
  49                 return NULL;
  50         }
  51         return (struct tag *) obj;
  52 }
  53
  54 static unsigned long parse_tag_date(const char *buf, const char *tail)
  55 {
  56         const char *dateptr;
  57
  58         while (buf < tail && *buf++ != '>')
  59                 /* nada */;
  60         if (buf >= tail)
  61                 return 0;
  62         dateptr = buf;
  63         while (buf < tail && *buf++ != '\n')
  64                 /* nada */;
  65         if (buf >= tail)
  66                 return 0;
  67         /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  68         return strtoul(dateptr, NULL, 10);
  69 }
  70
  71 int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
  72 {
  73         unsigned char sha1[20];
  74         char type[20];
  75         const char *bufptr = data;
  76         const char *tail = bufptr + size;
  77         const char *nl;
  78
  79         if (item->object.parsed)
  80                 return 0;
  81         item->object.parsed = 1;
  82
  83         if (size < 64)
  84                 return -1;
  85         if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
  86                 return -1;
  87         bufptr += 48; /* "object " + sha1 + "\n" */
  88
  89         if (prefixcmp(bufptr, "type "))
  90                 return -1;
  91         bufptr += 5;
  92         nl = memchr(bufptr, '\n', tail - bufptr);
  93         if (!nl || sizeof(type) <= (nl - bufptr))
  94                 return -1;
  95         strncpy(type, bufptr, nl - bufptr);
  96         type[nl - bufptr] = '\0';
  97         bufptr = nl + 1;
  98
  99         if (!strcmp(type, blob_type)) {
 100                 item->tagged = &lookup_blob(sha1)->object;
 101         } else if (!strcmp(type, tree_type)) {
 102                 item->tagged = &lookup_tree(sha1)->object;
 103         } else if (!strcmp(type, commit_type)) {
 104                 item->tagged = &lookup_commit(sha1)->object;
 105         } else if (!strcmp(type, tag_type)) {
 106                 item->tagged = &lookup_tag(sha1)->object;
 107         } else {
 108                 error("Unknown type %s", type);
 109                 item->tagged = NULL;
 110         }
 111
 112         if (bufptr + 4 < tail && !prefixcmp(bufptr, "tag "))
 113                 ;               /* good */
 114         else
 115                 return -1;
 116         bufptr += 4;
 117         nl = memchr(bufptr, '\n', tail - bufptr);
 118         if (!nl)
 119                 return -1;
 120         item->tag = xmemdupz(bufptr, nl - bufptr);
 121         bufptr = nl + 1;
 122
 123         if (bufptr + 7 < tail && !prefixcmp(bufptr, "tagger "))
 124                 item->date = parse_tag_date(bufptr, tail);
 125         else
 126                 item->date = 0;
 127
 128         return 0;
 129 }
 130
 131 int parse_tag(struct tag *item)
 132 {
 133         enum object_type type;
 134         void *data;
 135         unsigned long size;
 136         int ret;
 137
 138         if (item->object.parsed)
 139                 return 0;
 140         data = read_sha1_file(item->object.sha1, &type, &size);
 141         if (!data)
 142                 return error("Could not read %s",
 143                              sha1_to_hex(item->object.sha1));
 144         if (type != OBJ_TAG) {
 145                 free(data);
 146                 return error("Object %s not a tag",
 147                              sha1_to_hex(item->object.sha1));
 148         }
 149         ret = parse_tag_buffer(item, data, size);
 150         free(data);
 151         return ret;
 152 }
 153
 154 /*
 155  * Look at a signed tag object, and return the offset where
 156  * the embedded detached signature begins, or the end of the
 157  * data when there is no such signature.
 158  */
 159 size_t parse_signature(const char *buf, unsigned long size)
 160 {
 161         char *eol;
 162         size_t len = 0;
 163         while (len < size && prefixcmp(buf + len, PGP_SIGNATURE) &&
 164                         prefixcmp(buf + len, PGP_MESSAGE)) {
 165                 eol = memchr(buf + len, '\n', size - len);
 166                 len += eol ? eol - (buf + len) + 1 : size - len;
 167         }
 168         return len;
 169 }