On Fri, Feb 10, 2017 at 12:47:31PM -0800, John Johansen wrote:
> +typedef struct {
> + size_t size; /* length of s */
> + const char *entry; /* not necessarily NULL-terminated */
> +} aa_label_data_ent;
> +
> +typedef struct {
> + char *data; /* free data */
> + size_t n; /* number of ents */
> + aa_label_data_ent *ents; /* free vec of entries */
> +} aa_label_data_info;
Note that these use size_t, which can vary between 32 bit and 64 bit
platforms.
> +int aa_query_label_data(const char *label, const char *key,
> aa_label_data_info *out)
> +{
> + autofclose FILE *file = NULL;
> + const char *p;
> + uint32_t bytes;
> + uint32_t tmp;
> + int fd;
> +
> + if (!out)
> + return 0;
> +
> + memset(out, 0, sizeof(*out));
> +
> + fd = aa_query_label_data_open(label, key);
> + if (fd == -1)
> + return -1;
> +
> + file = fdopen(fd, "r+");
> + if (!file)
> + return -1;
> +
> + if (fread(&tmp, sizeof(tmp), 1, file) != 1) {
> + errno = EPROTO;
> + goto done;
> + }
> +
> + bytes = le32toh(tmp);
> + out->data = malloc(bytes);
> + if (!out->data) {
> + errno = ENOMEM;
> + goto done;
> + }
But here, only 32 bits is used.
> +
> + if (fread(out->data, sizeof(char), bytes, file) != bytes) {
> + errno = EPROTO;
> + goto done;
> + }
> +
> + p = out->data;
> + memcpy(&tmp, p, sizeof(tmp));
> + out->n = le32toh(tmp);
> + p += sizeof(tmp);
And here, only 32 bits is used.
Is this a problem? I suspect it's fine but wanted to point it out anyway.
> +
> + out->ents = malloc(out->n * sizeof(*out->ents));
If out->n is large enough, this multiplication might overflow. calloc()
would suffice but would be slightly wasteful.
> + if (!out->data) {
> + errno = ENOMEM;
> + goto done;
> + }
> +
> + for (int i = 0; i < out->n; i++) {
> + memcpy(&tmp, p, sizeof(tmp));
> + out->ents[i].size = le32toh(tmp);
> + p += sizeof(tmp);
> + out->ents[i].entry = p;
> + p += out->ents[i].size;
> + }
> +
> +done:
> + if (errno)
> + aa_clear_label_data(out);
> +
> + return errno ? -1 : 0;
> +}
Thanks
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