From 71bb49596bbf4e5a3328e1704d18604e822ba181 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp: Query supported CCIDs This provides a data structure to record which CCIDs are locally supported and three accessor functions: - a test function for internal use which is used to validate CCID requests made by the user; - a copy function so that the list can be used for feature-negotiation; - documented getsockopt() support so that the user can query capabilities. The data structure is a table which is filled in at compile-time with the list of available CCIDs (which in turn depends on the Kconfig choices). Using the copy function for cloning the list of supported CCIDs is useful for feature negotiation, since the negotiation is now with the full list of available CCIDs (e.g. {2, 3}) instead of the default value {2}. This means negotiation will not fail if the peer requests to use CCID3 instead of CCID2. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald --- net/dccp/ccid.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'net/dccp/ccid.c') diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c index 4809753d12ae..f72ca83df552 100644 --- a/net/dccp/ccid.c +++ b/net/dccp/ccid.c @@ -13,6 +13,13 @@ #include "ccid.h" +static u8 builtin_ccids[] = { + DCCPC_CCID2, /* CCID2 is supported by default */ +#if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE) + DCCPC_CCID3, +#endif +}; + static struct ccid_operations *ccids[CCID_MAX]; #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) static atomic_t ccids_lockct = ATOMIC_INIT(0); @@ -86,6 +93,47 @@ static void ccid_kmem_cache_destroy(struct kmem_cache *slab) } } +/* check that up to @array_len members in @ccid_array are supported */ +bool ccid_support_check(u8 const *ccid_array, u8 array_len) +{ + u8 i, j, found; + + for (i = 0, found = 0; i < array_len; i++, found = 0) { + for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++) + found = (ccid_array[i] == builtin_ccids[j]); + if (!found) + return false; + } + return true; +} + +/** + * ccid_get_builtin_ccids - Provide copy of `builtin' CCID array + * @ccid_array: pointer to copy into + * @array_len: value to return length into + * This function allocates memory - caller must see that it is freed after use. + */ +int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) +{ + *ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any()); + if (*ccid_array == NULL) + return -ENOBUFS; + *array_len = ARRAY_SIZE(builtin_ccids); + return 0; +} + +int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, + char __user *optval, int __user *optlen) +{ + if (len < sizeof(builtin_ccids)) + return -EINVAL; + + if (put_user(sizeof(builtin_ccids), optlen) || + copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids))) + return -EFAULT; + return 0; +} + int ccid_register(struct ccid_operations *ccid_ops) { int err = -ENOBUFS; -- cgit v1.2.2 From 78673e24df27c76ec75565f4024d45c2c74ef148 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp: Remove obsolete parts of the old CCID interface The TX/RX CCIDs of the minisock are now redundant: similar to the Ack Vector case, their value equals initially that of the sysctl, but at the end of feature negotiation may be something different. The old interface removed by this patch thus has been replaced by the newer interface to dynamically query the currently loaded CCIDs earlier in this patch set. Also removed the constructors for the TX CCID and the RX CCID, since the switch rx/non-rx is done by the handler in minisocks.c (and the handler is the only place in the code where CCIDs are loaded). Signed-off-by: Gerrit Renker Acked-by: Ian McDonald --- net/dccp/ccid.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'net/dccp/ccid.c') diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c index f72ca83df552..330372a1a0b6 100644 --- a/net/dccp/ccid.c +++ b/net/dccp/ccid.c @@ -253,20 +253,6 @@ out_module_put: EXPORT_SYMBOL_GPL(ccid_new); -struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp) -{ - return ccid_new(id, sk, 1, gfp); -} - -EXPORT_SYMBOL_GPL(ccid_hc_rx_new); - -struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk, gfp_t gfp) -{ - return ccid_new(id, sk, 0, gfp); -} - -EXPORT_SYMBOL_GPL(ccid_hc_tx_new); - static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx) { struct ccid_operations *ccid_ops; -- cgit v1.2.2 From 09856c108956c99088ead9267ccbd1dab77f7043 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp: Auto-load (when supported) CCID plugins for negotiation This adds auto-loading of CCIDs (when module loading is enabled) for the purpose of feature negotiation. The problem with loading the CCIDs at the end of feature negotiation is that this would happen in software interrupt context. Besides, if the host advertises CCIDs during negotiation, it should have them ready to use, in case an agreeing peer wants to use it for the connection. Signed-off-by: Gerrit Renker Signed-off-by: Ian McDonald --- net/dccp/ccid.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) (limited to 'net/dccp/ccid.c') diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c index 330372a1a0b6..e3fb52b4f5c6 100644 --- a/net/dccp/ccid.c +++ b/net/dccp/ccid.c @@ -196,22 +196,41 @@ int ccid_unregister(struct ccid_operations *ccid_ops) EXPORT_SYMBOL_GPL(ccid_unregister); +/** + * ccid_request_module - Pre-load CCID module for later use + * This should be called only from process context (e.g. during connection + * setup) and is necessary for later calls to ccid_new (typically in software + * interrupt), so that it has the modules available when they are needed. + */ +static int ccid_request_module(u8 id) +{ + if (!in_atomic()) { + ccids_read_lock(); + if (ccids[id] == NULL) { + ccids_read_unlock(); + return request_module("net-dccp-ccid-%d", id); + } + ccids_read_unlock(); + } + return 0; +} + +int ccid_request_modules(u8 const *ccid_array, u8 array_len) +{ +#ifdef CONFIG_KMOD + while (array_len--) + if (ccid_request_module(ccid_array[array_len])) + return -1; +#endif + return 0; +} + struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp) { struct ccid_operations *ccid_ops; struct ccid *ccid = NULL; ccids_read_lock(); -#ifdef CONFIG_KMOD - if (ccids[id] == NULL) { - /* We only try to load if in process context */ - ccids_read_unlock(); - if (gfp & GFP_ATOMIC) - goto out; - request_module("net-dccp-ccid-%d", id); - ccids_read_lock(); - } -#endif ccid_ops = ccids[id]; if (ccid_ops == NULL) goto out_unlock; -- cgit v1.2.2