diff options
| -rw-r--r-- | net/rxrpc/ar-key.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c index a3a7acb5071..bf4d623ee1c 100644 --- a/net/rxrpc/ar-key.c +++ b/net/rxrpc/ar-key.c @@ -29,6 +29,7 @@ static int rxrpc_instantiate_s(struct key *, const void *, size_t); static void rxrpc_destroy(struct key *); static void rxrpc_destroy_s(struct key *); static void rxrpc_describe(const struct key *, struct seq_file *); +static long rxrpc_read(const struct key *, char __user *, size_t); /* * rxrpc defined keys take an arbitrary string as the description and an @@ -40,6 +41,7 @@ struct key_type key_type_rxrpc = { .match = user_match, .destroy = rxrpc_destroy, .describe = rxrpc_describe, + .read = rxrpc_read, }; EXPORT_SYMBOL(key_type_rxrpc); @@ -592,3 +594,110 @@ struct key *rxrpc_get_null_key(const char *keyname) return key; } EXPORT_SYMBOL(rxrpc_get_null_key); + +/* + * read the contents of an rxrpc key + * - this returns the result in XDR form + */ +static long rxrpc_read(const struct key *key, + char __user *buffer, size_t buflen) +{ + struct rxrpc_key_token *token; + size_t size, toksize; + __be32 __user *xdr; + u32 cnlen, tktlen, ntoks, zero; + + _enter(""); + + /* we don't know what form we should return non-AFS keys in */ + if (memcmp(key->description, "afs@", 4) != 0) + return -EOPNOTSUPP; + cnlen = strlen(key->description + 4); + + /* AFS keys we return in XDR form, so we need to work out the size of + * the XDR */ + size = 2 * 4; /* flags, cellname len */ + size += (cnlen + 3) & ~3; /* cellname */ + size += 1 * 4; /* token count */ + + ntoks = 0; + for (token = key->payload.data; token; token = token->next) { + switch (token->security_index) { + case RXRPC_SECURITY_RXKAD: + size += 2 * 4; /* length, security index (switch ID) */ + size += 8 * 4; /* viceid, kvno, key*2, begin, end, + * primary, tktlen */ + size += (token->kad->ticket_len + 3) & ~3; /* ticket */ + ntoks++; + break; + + default: /* can't encode */ + break; + } + } + + if (!buffer || buflen < size) + return size; + + xdr = (__be32 __user *) buffer; + zero = 0; +#define ENCODE(x) \ + do { \ + __be32 y = htonl(x); \ + if (put_user(y, xdr++) < 0) \ + goto fault; \ + } while(0) + + ENCODE(0); /* flags */ + ENCODE(cnlen); /* cellname length */ + if (copy_to_user(xdr, key->description + 4, cnlen) != 0) + goto fault; + if (cnlen & 3 && + copy_to_user((u8 *)xdr + cnlen, &zero, 4 - (cnlen & 3)) != 0) + goto fault; + xdr += (cnlen + 3) >> 2; + ENCODE(ntoks); /* token count */ + + for (token = key->payload.data; token; token = token->next) { + toksize = 1 * 4; /* sec index */ + + switch (token->security_index) { + case RXRPC_SECURITY_RXKAD: + toksize += 8 * 4; + toksize += (token->kad->ticket_len + 3) & ~3; + ENCODE(toksize); + ENCODE(token->security_index); + ENCODE(token->kad->vice_id); + ENCODE(token->kad->kvno); + if (copy_to_user(xdr, token->kad->session_key, 8) != 0) + goto fault; + xdr += 8 >> 2; + ENCODE(token->kad->start); + ENCODE(token->kad->expiry); + ENCODE(token->kad->primary_flag); + tktlen = token->kad->ticket_len; + ENCODE(tktlen); + if (copy_to_user(xdr, token->kad->ticket, tktlen) != 0) + goto fault; + if (tktlen & 3 && + copy_to_user((u8 *)xdr + tktlen, &zero, + 4 - (tktlen & 3)) != 0) + goto fault; + xdr += (tktlen + 3) >> 2; + break; + + default: + break; + } + } + +#undef ENCODE + + ASSERTCMP((char __user *) xdr - buffer, ==, size); + _leave(" = %zu", size); + return size; + +fault: + _leave(" = -EFAULT"); + return -EFAULT; +} |