From fe4944e59c357f945f81bc67edb7ed1392e875ad Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Fri, 4 Aug 2006 23:03:05 -0700 Subject: [NETLINK]: Extend netlink messaging interface Adds: nlmsg_get_pos() return current position in message nlmsg_trim() trim part of message nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr nla_put_nohdr(skb, len, data) add attribute w/o hdr nla_find_nested() find attribute in nested attributes Fixes nlmsg_new() to take allocation flags and consider size. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 74 ++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 64 insertions(+), 10 deletions(-) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index 640c26a90cf1..3a5e40b1e045 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -35,6 +35,8 @@ * nlmsg_put() add a netlink message to an skb * nlmsg_put_answer() callback based nlmsg_put() * nlmsg_end() finanlize netlink message + * nlmsg_get_pos() return current position in message + * nlmsg_trim() trim part of message * nlmsg_cancel() cancel message construction * nlmsg_free() free a netlink message * @@ -80,8 +82,10 @@ * struct nlattr netlink attribtue header * * Attribute Construction: - * nla_reserve(skb, type, len) reserve skb tailroom for an attribute + * nla_reserve(skb, type, len) reserve room for an attribute + * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr * nla_put(skb, type, len, data) add attribute to skb + * nla_put_nohdr(skb, len, data) add attribute w/o hdr * * Attribute Construction for Basic Types: * nla_put_u8(skb, type, value) add u8 attribute to skb @@ -139,6 +143,7 @@ * nla_next(nla, remaining) get next netlink attribute * nla_validate() validate a stream of attributes * nla_find() find attribute in stream of attributes + * nla_find_nested() find attribute in nested attributes * nla_parse() parse and validate stream of attrs * nla_parse_nested() parse nested attribuets * nla_for_each_attr() loop over all attributes @@ -203,12 +208,18 @@ extern int nla_memcmp(const struct nlattr *nla, const void *data, extern int nla_strcmp(const struct nlattr *nla, const char *str); extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen); extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, int attrlen); +extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); extern void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); +extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, + const void *data); extern int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data); +extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, + const void *data); /************************************************************************** * Netlink Messages @@ -453,12 +464,13 @@ static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, /** * nlmsg_new - Allocate a new netlink message * @size: maximum size of message + * @flags: the type of memory to allocate. * * Use NLMSG_GOODSIZE if size isn't know and you need a good default size. */ -static inline struct sk_buff *nlmsg_new(int size) +static inline struct sk_buff *nlmsg_new(int size, gfp_t flags) { - return alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + return alloc_skb(size, flags); } /** @@ -479,6 +491,32 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) return skb->len; } +/** + * nlmsg_get_pos - return current position in netlink message + * @skb: socket buffer the message is stored in + * + * Returns a pointer to the current tail of the message. + */ +static inline void *nlmsg_get_pos(struct sk_buff *skb) +{ + return skb->tail; +} + +/** + * nlmsg_trim - Trim message to a mark + * @skb: socket buffer the message is stored in + * @mark: mark to trim to + * + * Trims the message to the provided mark. Returns -1. + */ +static inline int nlmsg_trim(struct sk_buff *skb, void *mark) +{ + if (mark) + skb_trim(skb, (unsigned char *) mark - skb->data); + + return -1; +} + /** * nlmsg_cancel - Cancel construction of a netlink message * @skb: socket buffer the message is stored in @@ -489,9 +527,7 @@ static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) */ static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) { - skb_trim(skb, (unsigned char *) nlh - skb->data); - - return -1; + return nlmsg_trim(skb, nlh); } /** @@ -630,6 +666,18 @@ static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) return (struct nlattr *) ((char *) nla + totlen); } +/** + * nla_find_nested - find attribute in a set of nested attributes + * @nla: attribute containing the nested attributes + * @attrtype: type of attribute to look for + * + * Returns the first attribute which matches the specified type. + */ +static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) +{ + return nla_find(nla_data(nla), nla_len(nla), attrtype); +} + /** * nla_parse_nested - parse nested attributes * @tb: destination array with maxtype+1 elements @@ -862,10 +910,7 @@ static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) */ static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) { - if (start) - skb_trim(skb, (unsigned char *) start - skb->data); - - return -1; + return nlmsg_trim(skb, start); } /** @@ -880,4 +925,13 @@ static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) nla_ok(pos, rem); \ pos = nla_next(pos, &(rem))) +/** + * nla_for_each_nested - iterate over nested attributes + * @pos: loop counter, set to current attribute + * @nla: attribute containing the nested attributes + * @rem: initialized to len, holds bytes currently remaining in stream + */ +#define nla_for_each_nested(pos, nla, rem) \ + nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) + #endif -- cgit v1.2.3 From d387f6ad10764fc2174373b4a1cca443adee36e3 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 15 Aug 2006 00:31:06 -0700 Subject: [NETLINK]: Add notification message sending interface Adds nlmsg_notify() implementing proper notification logic. The message is multicasted to all listeners in the group. The applications the requests orignates from can request a unicast back report in which case said socket will be excluded from the multicast to avoid duplicated notifications. nlmsg_multicast() is extended to take allocation flags to allow notification in atomic contexts. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index 3a5e40b1e045..b154b81d9a7a 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -43,6 +43,7 @@ * Message Sending: * nlmsg_multicast() multicast message to several groups * nlmsg_unicast() unicast a message to a single socket + * nlmsg_notify() send notification message * * Message Length Calculations: * nlmsg_msg_size(payload) length of message w/o padding @@ -545,15 +546,16 @@ static inline void nlmsg_free(struct sk_buff *skb) * @skb: netlink message as socket buffer * @pid: own netlink pid to avoid sending to yourself * @group: multicast group id + * @flags: allocation flags */ static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, - u32 pid, unsigned int group) + u32 pid, unsigned int group, gfp_t flags) { int err; NETLINK_CB(skb).dst_group = group; - err = netlink_broadcast(sk, skb, pid, group, GFP_KERNEL); + err = netlink_broadcast(sk, skb, pid, group, flags); if (err > 0) err = 0; -- cgit v1.2.3 From 97676b6b5538b3e059d33b8338e7d5cc41c5f1f1 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 15 Aug 2006 00:31:41 -0700 Subject: [RTNETLINK]: Add rtnetlink notification interface Adds rtnl_notify() to send rtnetlink notification messages and rtnl_set_sk_err() to report notification errors as socket errors in order to indicate the need of a resync due to loss of events. nlmsg_report() is added to properly document the meaning of NLM_F_ECHO. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index b154b81d9a7a..bf593eb59e1b 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -65,6 +65,9 @@ * nlmsg_validate() validate netlink message incl. attrs * nlmsg_for_each_attr() loop over all attributes * + * Misc: + * nlmsg_report() report back to application? + * * ------------------------------------------------------------------------ * Attributes Interface * ------------------------------------------------------------------------ @@ -194,6 +197,9 @@ extern void netlink_run_queue(struct sock *sk, unsigned int *qlen, struct nlmsghdr *, int *)); extern void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb); +extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, + u32 pid, unsigned int group, int report, + gfp_t flags); extern int nla_validate(struct nlattr *head, int len, int maxtype, struct nla_policy *policy); @@ -375,6 +381,17 @@ static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, nlmsg_attrlen(nlh, hdrlen), maxtype, policy); } +/** + * nlmsg_report - need to report back to application? + * @nlh: netlink message header + * + * Returns 1 if a report back to the application is requested. + */ +static inline int nlmsg_report(struct nlmsghdr *nlh) +{ + return !!(nlh->nlmsg_flags & NLM_F_ECHO); +} + /** * nlmsg_for_each_attr - iterate over a stream of attributes * @pos: loop counter, set to current attribute -- cgit v1.2.3 From 4e902c57417c4c285b98ba2722468d1c3ed83d1b Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Thu, 17 Aug 2006 18:14:52 -0700 Subject: [IPv4]: FIB configuration using struct fib_config Introduces struct fib_config replacing the ugly struct kern_rta prone to ordering issues. Avoids creating faked netlink messages for auto generated routes or requests via ioctl. A new interface net/nexthop.h is added to help navigate through nexthop configuration arrays. A new struct nl_info will be used to carry the necessary netlink information to be used for notifications later on. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index bf593eb59e1b..47044da167c5 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -192,6 +192,16 @@ struct nla_policy { u16 minlen; }; +/** + * struct nl_info - netlink source information + * @nlh: Netlink message header of original request + * @pid: Netlink PID of requesting application + */ +struct nl_info { + struct nlmsghdr *nlh; + u32 pid; +}; + extern void netlink_run_queue(struct sock *sk, unsigned int *qlen, int (*cb)(struct sk_buff *, struct nlmsghdr *, int *)); -- cgit v1.2.3 From ff5dfe736dd9f6c74b206aa77c0465dfd503bdb9 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Sat, 26 Aug 2006 19:17:53 -0700 Subject: [NETLINK]: remove third bogus argument from NLA_PUT_FLAG This patch removes the 'value' argument from NLA_PUT_FLAG which is unused anyway. The documentation comment was already correct so it doesn't need an update :) Signed-off-by: Johannes Berg Signed-off-by: David S. Miller --- include/net/netlink.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index 47044da167c5..bcb27e3a312e 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -828,7 +828,7 @@ static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, #define NLA_PUT_STRING(skb, attrtype, value) \ NLA_PUT(skb, attrtype, strlen(value) + 1, value) -#define NLA_PUT_FLAG(skb, attrtype, value) \ +#define NLA_PUT_FLAG(skb, attrtype) \ NLA_PUT(skb, attrtype, 0, NULL) #define NLA_PUT_MSECS(skb, attrtype, jiffies) \ -- cgit v1.2.3 From a5531a5d852008be40811496029012f4ad3093d1 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Sat, 26 Aug 2006 20:11:47 -0700 Subject: [NETLINK]: Improve string attribute validation Introduces a new attribute type NLA_NUL_STRING to support NUL terminated strings. Attributes of this kind require to carry a terminating NUL within the maximum specified in the policy. The `old' NLA_STRING which is not required to be NUL terminated is extended to provide means to specify a maximum length of the string. Aims at easing the pain with using nla_strlcpy() on temporary buffers. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- include/net/netlink.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'include/net/netlink.h') diff --git a/include/net/netlink.h b/include/net/netlink.h index bcb27e3a312e..11dc2e7f679a 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -167,6 +167,7 @@ enum { NLA_FLAG, NLA_MSECS, NLA_NESTED, + NLA_NUL_STRING, __NLA_TYPE_MAX, }; @@ -175,21 +176,27 @@ enum { /** * struct nla_policy - attribute validation policy * @type: Type of attribute or NLA_UNSPEC - * @minlen: Minimal length of payload required to be available + * @len: Type specific length of payload * * Policies are defined as arrays of this struct, the array must be * accessible by attribute type up to the highest identifier to be expected. * + * Meaning of `len' field: + * NLA_STRING Maximum length of string + * NLA_NUL_STRING Maximum length of string (excluding NUL) + * NLA_FLAG Unused + * All other Exact length of attribute payload + * * Example: * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { * [ATTR_FOO] = { .type = NLA_U16 }, - * [ATTR_BAR] = { .type = NLA_STRING }, - * [ATTR_BAZ] = { .minlen = sizeof(struct mystruct) }, + * [ATTR_BAR] = { .type = NLA_STRING, len = BARSIZ }, + * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, * }; */ struct nla_policy { u16 type; - u16 minlen; + u16 len; }; /** -- cgit v1.2.3