diff options
author | Steve French <sfrench@us.ibm.com> | 2005-11-10 15:34:57 -0800 |
---|---|---|
committer | Steve French <sfrench@us.ibm.com> | 2005-11-10 15:34:57 -0800 |
commit | 9551583e55e26a0940894828c2d1066e9276325e (patch) | |
tree | ff412949400da94aa788bd094ced2138e9175935 /net/netlink | |
parent | a2653ebab3a96c6e6183360821faa492c1f88c3f (diff) | |
parent | 985834a1c3a2e9639145bd8ea16af6e25f2143ad (diff) |
Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Diffstat (limited to 'net/netlink')
-rw-r--r-- | net/netlink/Makefile | 2 | ||||
-rw-r--r-- | net/netlink/af_netlink.c | 97 | ||||
-rw-r--r-- | net/netlink/attr.c | 328 | ||||
-rw-r--r-- | net/netlink/genetlink.c | 579 |
4 files changed, 1003 insertions, 3 deletions
diff --git a/net/netlink/Makefile b/net/netlink/Makefile index 39d9c2dcd03..e3589c2de49 100644 --- a/net/netlink/Makefile +++ b/net/netlink/Makefile @@ -2,4 +2,4 @@ # Makefile for the netlink driver. # -obj-y := af_netlink.o +obj-y := af_netlink.o attr.o genetlink.o diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 5ca283537bc..8c38ee6d255 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -58,6 +58,7 @@ #include <net/sock.h> #include <net/scm.h> +#include <net/netlink.h> #define Nprintk(a...) #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) @@ -427,7 +428,8 @@ static int netlink_release(struct socket *sock) spin_lock(&nlk->cb_lock); if (nlk->cb) { - nlk->cb->done(nlk->cb); + if (nlk->cb->done) + nlk->cb->done(nlk->cb); netlink_destroy_callback(nlk->cb); nlk->cb = NULL; } @@ -1322,7 +1324,8 @@ static int netlink_dump(struct sock *sk) skb_queue_tail(&sk->sk_receive_queue, skb); sk->sk_data_ready(sk, skb->len); - cb->done(cb); + if (cb->done) + cb->done(cb); nlk->cb = NULL; spin_unlock(&nlk->cb_lock); @@ -1409,6 +1412,94 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); } +static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, + struct nlmsghdr *, int *)) +{ + unsigned int total_len; + struct nlmsghdr *nlh; + int err; + + while (skb->len >= nlmsg_total_size(0)) { + nlh = (struct nlmsghdr *) skb->data; + + if (skb->len < nlh->nlmsg_len) + return 0; + + total_len = min(NLMSG_ALIGN(nlh->nlmsg_len), skb->len); + + if (cb(skb, nlh, &err) < 0) { + /* Not an error, but we have to interrupt processing + * here. Note: that in this case we do not pull + * message from skb, it will be processed later. + */ + if (err == 0) + return -1; + netlink_ack(skb, nlh, err); + } else if (nlh->nlmsg_flags & NLM_F_ACK) + netlink_ack(skb, nlh, 0); + + skb_pull(skb, total_len); + } + + return 0; +} + +/** + * nelink_run_queue - Process netlink receive queue. + * @sk: Netlink socket containing the queue + * @qlen: Place to store queue length upon entry + * @cb: Callback function invoked for each netlink message found + * + * Processes as much as there was in the queue upon entry and invokes + * a callback function for each netlink message found. The callback + * function may refuse a message by returning a negative error code + * but setting the error pointer to 0 in which case this function + * returns with a qlen != 0. + * + * qlen must be initialized to 0 before the initial entry, afterwards + * the function may be called repeatedly until qlen reaches 0. + */ +void netlink_run_queue(struct sock *sk, unsigned int *qlen, + int (*cb)(struct sk_buff *, struct nlmsghdr *, int *)) +{ + struct sk_buff *skb; + + if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue)) + *qlen = skb_queue_len(&sk->sk_receive_queue); + + for (; *qlen; (*qlen)--) { + skb = skb_dequeue(&sk->sk_receive_queue); + if (netlink_rcv_skb(skb, cb)) { + if (skb->len) + skb_queue_head(&sk->sk_receive_queue, skb); + else { + kfree_skb(skb); + (*qlen)--; + } + break; + } + + kfree_skb(skb); + } +} + +/** + * netlink_queue_skip - Skip netlink message while processing queue. + * @nlh: Netlink message to be skipped + * @skb: Socket buffer containing the netlink messages. + * + * Pulls the given netlink message off the socket buffer so the next + * call to netlink_queue_run() will not reconsider the message. + */ +void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb) +{ + int msglen = NLMSG_ALIGN(nlh->nlmsg_len); + + if (msglen > skb->len) + msglen = skb->len; + + skb_pull(skb, msglen); +} #ifdef CONFIG_PROC_FS struct nl_seq_iter { @@ -1657,6 +1748,8 @@ out: core_initcall(netlink_proto_init); EXPORT_SYMBOL(netlink_ack); +EXPORT_SYMBOL(netlink_run_queue); +EXPORT_SYMBOL(netlink_queue_skip); EXPORT_SYMBOL(netlink_broadcast); EXPORT_SYMBOL(netlink_dump_start); EXPORT_SYMBOL(netlink_kernel_create); diff --git a/net/netlink/attr.c b/net/netlink/attr.c new file mode 100644 index 00000000000..fffef4ab276 --- /dev/null +++ b/net/netlink/attr.c @@ -0,0 +1,328 @@ +/* + * NETLINK Netlink attributes + * + * Authors: Thomas Graf <tgraf@suug.ch> + * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/jiffies.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/string.h> +#include <linux/types.h> +#include <net/netlink.h> + +static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { + [NLA_U8] = sizeof(u8), + [NLA_U16] = sizeof(u16), + [NLA_U32] = sizeof(u32), + [NLA_U64] = sizeof(u64), + [NLA_STRING] = 1, + [NLA_NESTED] = NLA_HDRLEN, +}; + +static int validate_nla(struct nlattr *nla, int maxtype, + struct nla_policy *policy) +{ + struct nla_policy *pt; + int minlen = 0; + + if (nla->nla_type <= 0 || nla->nla_type > maxtype) + return 0; + + pt = &policy[nla->nla_type]; + + BUG_ON(pt->type > NLA_TYPE_MAX); + + if (pt->minlen) + minlen = pt->minlen; + else if (pt->type != NLA_UNSPEC) + minlen = nla_attr_minlen[pt->type]; + + if (pt->type == NLA_FLAG && nla_len(nla) > 0) + return -ERANGE; + + if (nla_len(nla) < minlen) + return -ERANGE; + + return 0; +} + +/** + * nla_validate - Validate a stream of attributes + * @head: head of attribute stream + * @len: length of attribute stream + * @maxtype: maximum attribute type to be expected + * @policy: validation policy + * + * Validates all attributes in the specified attribute stream against the + * specified policy. Attributes with a type exceeding maxtype will be + * ignored. See documenation of struct nla_policy for more details. + * + * Returns 0 on success or a negative error code. + */ +int nla_validate(struct nlattr *head, int len, int maxtype, + struct nla_policy *policy) +{ + struct nlattr *nla; + int rem, err; + + nla_for_each_attr(nla, head, len, rem) { + err = validate_nla(nla, maxtype, policy); + if (err < 0) + goto errout; + } + + err = 0; +errout: + return err; +} + +/** + * nla_parse - Parse a stream of attributes into a tb buffer + * @tb: destination array with maxtype+1 elements + * @maxtype: maximum attribute type to be expected + * @head: head of attribute stream + * @len: length of attribute stream + * + * Parses a stream of attributes and stores a pointer to each attribute in + * the tb array accessable via the attribute type. Attributes with a type + * exceeding maxtype will be silently ignored for backwards compatibility + * reasons. policy may be set to NULL if no validation is required. + * + * Returns 0 on success or a negative error code. + */ +int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, + struct nla_policy *policy) +{ + struct nlattr *nla; + int rem, err; + + memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); + + nla_for_each_attr(nla, head, len, rem) { + u16 type = nla->nla_type; + + if (type > 0 && type <= maxtype) { + if (policy) { + err = validate_nla(nla, maxtype, policy); + if (err < 0) + goto errout; + } + + tb[type] = nla; + } + } + + if (unlikely(rem > 0)) + printk(KERN_WARNING "netlink: %d bytes leftover after parsing " + "attributes.\n", rem); + + err = 0; +errout: + return err; +} + +/** + * nla_find - Find a specific attribute in a stream of attributes + * @head: head of attribute stream + * @len: length of attribute stream + * @attrtype: type of attribute to look for + * + * Returns the first attribute in the stream matching the specified type. + */ +struct nlattr *nla_find(struct nlattr *head, int len, int attrtype) +{ + struct nlattr *nla; + int rem; + + nla_for_each_attr(nla, head, len, rem) + if (nla->nla_type == attrtype) + return nla; + + return NULL; +} + +/** + * nla_strlcpy - Copy string attribute payload into a sized buffer + * @dst: where to copy the string to + * @src: attribute to copy the string from + * @dstsize: size of destination buffer + * + * Copies at most dstsize - 1 bytes into the destination buffer. + * The result is always a valid NUL-terminated string. Unlike + * strlcpy the destination buffer is always padded out. + * + * Returns the length of the source buffer. + */ +size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize) +{ + size_t srclen = nla_len(nla); + char *src = nla_data(nla); + + if (srclen > 0 && src[srclen - 1] == '\0') + srclen--; + + if (dstsize > 0) { + size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen; + + memset(dst, 0, dstsize); + memcpy(dst, src, len); + } + + return srclen; +} + +/** + * nla_memcpy - Copy a netlink attribute into another memory area + * @dest: where to copy to memcpy + * @src: netlink attribute to copy from + * @count: size of the destination area + * + * Note: The number of bytes copied is limited by the length of + * attribute's payload. memcpy + * + * Returns the number of bytes copied. + */ +int nla_memcpy(void *dest, struct nlattr *src, int count) +{ + int minlen = min_t(int, count, nla_len(src)); + + memcpy(dest, nla_data(src), minlen); + + return minlen; +} + +/** + * nla_memcmp - Compare an attribute with sized memory area + * @nla: netlink attribute + * @data: memory area + * @size: size of memory area + */ +int nla_memcmp(const struct nlattr *nla, const void *data, + size_t size) +{ + int d = nla_len(nla) - size; + + if (d == 0) + d = memcmp(nla_data(nla), data, size); + + return d; +} + +/** + * nla_strcmp - Compare a string attribute against a string + * @nla: netlink string attribute + * @str: another string + */ +int nla_strcmp(const struct nlattr *nla, const char *str) +{ + int len = strlen(str) + 1; + int d = nla_len(nla) - len; + + if (d == 0) + d = memcmp(nla_data(nla), str, len); + + return d; +} + +/** + * __nla_reserve - reserve room for attribute on the skb + * @skb: socket buffer to reserve room on + * @attrtype: attribute type + * @attrlen: length of attribute payload + * + * Adds a netlink attribute header to a socket buffer and reserves + * room for the payload but does not copy it. + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) +{ + struct nlattr *nla; + + nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen)); + nla->nla_type = attrtype; + nla->nla_len = nla_attr_size(attrlen); + + memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen)); + + return nla; +} + +/** + * nla_reserve - reserve room for attribute on the skb + * @skb: socket buffer to reserve room on + * @attrtype: attribute type + * @attrlen: length of attribute payload + * + * Adds a netlink attribute header to a socket buffer and reserves + * room for the payload but does not copy it. + * + * Returns NULL if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen) +{ + if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) + return NULL; + + return __nla_reserve(skb, attrtype, attrlen); +} + +/** + * __nla_put - Add a netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * The caller is responsible to ensure that the skb provides enough + * tailroom for the attribute header and payload. + */ +void __nla_put(struct sk_buff *skb, int attrtype, int attrlen, + const void *data) +{ + struct nlattr *nla; + + nla = __nla_reserve(skb, attrtype, attrlen); + memcpy(nla_data(nla), data, attrlen); +} + + +/** + * nla_put - Add a netlink attribute to a socket buffer + * @skb: socket buffer to add attribute to + * @attrtype: attribute type + * @attrlen: length of attribute payload + * @data: head of attribute payload + * + * Returns -1 if the tailroom of the skb is insufficient to store + * the attribute header and payload. + */ +int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data) +{ + if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen))) + return -1; + + __nla_put(skb, attrtype, attrlen, data); + return 0; +} + + +EXPORT_SYMBOL(nla_validate); +EXPORT_SYMBOL(nla_parse); +EXPORT_SYMBOL(nla_find); +EXPORT_SYMBOL(nla_strlcpy); +EXPORT_SYMBOL(__nla_reserve); +EXPORT_SYMBOL(nla_reserve); +EXPORT_SYMBOL(__nla_put); +EXPORT_SYMBOL(nla_put); +EXPORT_SYMBOL(nla_memcpy); +EXPORT_SYMBOL(nla_memcmp); +EXPORT_SYMBOL(nla_strcmp); diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c new file mode 100644 index 00000000000..287cfcc5695 --- /dev/null +++ b/net/netlink/genetlink.c @@ -0,0 +1,579 @@ +/* + * NETLINK Generic Netlink Family + * + * Authors: Jamal Hadi Salim + * Thomas Graf <tgraf@suug.ch> + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/string.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/genetlink.h> + +struct sock *genl_sock = NULL; + +static DECLARE_MUTEX(genl_sem); /* serialization of message processing */ + +static void genl_lock(void) +{ + down(&genl_sem); +} + +static int genl_trylock(void) +{ + return down_trylock(&genl_sem); +} + +static void genl_unlock(void) +{ + up(&genl_sem); + + if (genl_sock && genl_sock->sk_receive_queue.qlen) + genl_sock->sk_data_ready(genl_sock, 0); +} + +#define GENL_FAM_TAB_SIZE 16 +#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1) + +static struct list_head family_ht[GENL_FAM_TAB_SIZE]; + +static int genl_ctrl_event(int event, void *data); + +static inline unsigned int genl_family_hash(unsigned int id) +{ + return id & GENL_FAM_TAB_MASK; +} + +static inline struct list_head *genl_family_chain(unsigned int id) +{ + return &family_ht[genl_family_hash(id)]; +} + +static struct genl_family *genl_family_find_byid(unsigned int id) +{ + struct genl_family *f; + + list_for_each_entry(f, genl_family_chain(id), family_list) + if (f->id == id) + return f; + + return NULL; +} + +static struct genl_family *genl_family_find_byname(char *name) +{ + struct genl_family *f; + int i; + + for (i = 0; i < GENL_FAM_TAB_SIZE; i++) + list_for_each_entry(f, genl_family_chain(i), family_list) + if (strcmp(f->name, name) == 0) + return f; + + return NULL; +} + +static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) +{ + struct genl_ops *ops; + + list_for_each_entry(ops, &family->ops_list, ops_list) + if (ops->cmd == cmd) + return ops; + + return NULL; +} + +/* Of course we are going to have problems once we hit + * 2^16 alive types, but that can only happen by year 2K +*/ +static inline u16 genl_generate_id(void) +{ + static u16 id_gen_idx; + int overflowed = 0; + + do { + if (id_gen_idx == 0) + id_gen_idx = GENL_MIN_ID; + + if (++id_gen_idx > GENL_MAX_ID) { + if (!overflowed) { + overflowed = 1; + id_gen_idx = 0; + continue; + } else + return 0; + } + + } while (genl_family_find_byid(id_gen_idx)); + + return id_gen_idx; +} + +/** + * genl_register_ops - register generic netlink operations + * @family: generic netlink family + * @ops: operations to be registered + * + * Registers the specified operations and assigns them to the specified + * family. Either a doit or dumpit callback must be specified or the + * operation will fail. Only one operation structure per command + * identifier may be registered. + * + * See include/net/genetlink.h for more documenation on the operations + * structure. + * + * Returns 0 on success or a negative error code. + */ +int genl_register_ops(struct genl_family *family, struct genl_ops *ops) +{ + int err = -EINVAL; + + if (ops->dumpit == NULL && ops->doit == NULL) + goto errout; + + if (genl_get_cmd(ops->cmd, family)) { + err = -EEXIST; + goto errout; + } + + genl_lock(); + list_add_tail(&ops->ops_list, &family->ops_list); + genl_unlock(); + + genl_ctrl_event(CTRL_CMD_NEWOPS, ops); + err = 0; +errout: + return err; +} + +/** + * genl_unregister_ops - unregister generic netlink operations + * @family: generic netlink family + * @ops: operations to be unregistered + * + * Unregisters the specified operations and unassigns them from the + * specified family. The operation blocks until the current message + * processing has finished and doesn't start again until the + * unregister process has finished. + * + * Note: It is not necessary to unregister all operations before + * unregistering the family, unregistering the family will cause + * all assigned operations to be unregistered automatically. + * + * Returns 0 on success or a negative error code. + */ +int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops) +{ + struct genl_ops *rc; + + genl_lock(); + list_for_each_entry(rc, &family->ops_list, ops_list) { + if (rc == ops) { + list_del(&ops->ops_list); + genl_unlock(); + genl_ctrl_event(CTRL_CMD_DELOPS, ops); + return 0; + } + } + genl_unlock(); + + return -ENOENT; +} + +/** + * genl_register_family - register a generic netlink family + * @family: generic netlink family + * + * Registers the specified family after validating it first. Only one + * family may be registered with the same family name or identifier. + * The family id may equal GENL_ID_GENERATE causing an unique id to + * be automatically generated and assigned. + * + * Return 0 on success or a negative error code. + */ +int genl_register_family(struct genl_family *family) +{ + int err = -EINVAL; + + if (family->id && family->id < GENL_MIN_ID) + goto errout; + + if (family->id > GENL_MAX_ID) + goto errout; + + INIT_LIST_HEAD(&family->ops_list); + + genl_lock(); + + if (genl_family_find_byname(family->name)) { + err = -EEXIST; + goto errout_locked; + } + + if (genl_family_find_byid(family->id)) { + err = -EEXIST; + goto errout_locked; + } + + if (!try_module_get(family->owner)) { + err = -EBUSY; + goto errout_locked; + } + + if (family->id == GENL_ID_GENERATE) { + u16 newid = genl_generate_id(); + + if (!newid) { + err = -ENOMEM; + goto errout_locked; + } + + family->id = newid; + } + + if (family->maxattr) { + family->attrbuf = kmalloc((family->maxattr+1) * + sizeof(struct nlattr *), GFP_KERNEL); + if (family->attrbuf == NULL) { + err = -ENOMEM; + goto errout; + } + } else + family->attrbuf = NULL; + + list_add_tail(&family->family_list, genl_family_chain(family->id)); + genl_unlock(); + + genl_ctrl_event(CTRL_CMD_NEWFAMILY, family); + + return 0; + +errout_locked: + genl_unlock(); +errout: + return err; +} + +/** + * genl_unregister_family - unregister generic netlink family + * @family: generic netlink family + * + * Unregisters the specified family. + * + * Returns 0 on success or a negative error code. + */ +int genl_unregister_family(struct genl_family *family) +{ + struct genl_family *rc; + + genl_lock(); + + list_for_each_entry(rc, genl_family_chain(family->id), family_list) { + if (family->id != rc->id || strcmp(rc->name, family->name)) + continue; + + list_del(&rc->family_list); + INIT_LIST_HEAD(&family->ops_list); + genl_unlock(); + + module_put(family->owner); + kfree(family->attrbuf); + genl_ctrl_event(CTRL_CMD_DELFAMILY, family); + return 0; + } + + genl_unlock(); + + return -ENOENT; +} + +static inline int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, + int *errp) +{ + struct genl_ops *ops; + struct genl_family *family; + struct genl_info info; + struct genlmsghdr *hdr = nlmsg_data(nlh); + int hdrlen, err = -EINVAL; + + if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) + goto ignore; + + if (nlh->nlmsg_type < NLMSG_MIN_TYPE) + goto ignore; + + family = genl_family_find_byid(nlh->nlmsg_type); + if (family == NULL) { + err = -ENOENT; + goto errout; + } + + hdrlen = GENL_HDRLEN + family->hdrsize; + if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) + goto errout; + + ops = genl_get_cmd(hdr->cmd, family); + if (ops == NULL) { + err = -EOPNOTSUPP; + goto errout; + } + + if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb)) { + err = -EPERM; + goto errout; + } + + if (nlh->nlmsg_flags & NLM_F_DUMP) { + if (ops->dumpit == NULL) { + err = -EOPNOTSUPP; + goto errout; + } + + *errp = err = netlink_dump_start(genl_sock, skb, nlh, + ops->dumpit, NULL); + if (err == 0) + skb_pull(skb, min(NLMSG_ALIGN(nlh->nlmsg_len), + skb->len)); + return -1; + } + + if (ops->doit == NULL) { + err = -EOPNOTSUPP; + goto errout; + } + + if (family->attrbuf) { + err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr, + ops->policy); + if (err < 0) + goto errout; + } + + info.snd_seq = nlh->nlmsg_seq; + info.snd_pid = NETLINK_CB(skb).pid; + info.nlhdr = nlh; + info.genlhdr = nlmsg_data(nlh); + info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; + info.attrs = family->attrbuf; + + *errp = err = ops->doit(skb, &info); + return err; + +ignore: + return 0; + +errout: + *errp = err; + return -1; +} + +static void genl_rcv(struct sock *sk, int len) +{ + unsigned int qlen = 0; + + do { + if (genl_trylock()) + return; + netlink_run_queue(sk, &qlen, &genl_rcv_msg); + genl_unlock(); + } while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen); +} + +/************************************************************************** + * Controller + **************************************************************************/ + +static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq, + u32 flags, struct sk_buff *skb, u8 cmd) +{ + void *hdr; + + hdr = genlmsg_put(skb, pid, seq, GENL_ID_CTRL, 0, flags, cmd, + family->version); + if (hdr == NULL) + return -1; + + NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name); + NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id); + + return genlmsg_end(skb, hdr); + +nla_put_failure: + return genlmsg_cancel(skb, hdr); +} + +static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) +{ + + int i, n = 0; + struct genl_family *rt; + int chains_to_skip = cb->args[0]; + int fams_to_skip = cb->args[1]; + + for (i = 0; i < GENL_FAM_TAB_SIZE; i++) { + if (i < chains_to_skip) + continue; + n = 0; + list_for_each_entry(rt, genl_family_chain(i), family_list) { + if (++n < fams_to_skip) + continue; + if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + skb, CTRL_CMD_NEWFAMILY) < 0) + goto errout; + } + + fams_to_skip = 0; + } + +errout: + cb->args[0] = i; + cb->args[1] = n; + + return skb->len; +} + +static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, + int seq, int cmd) +{ + struct sk_buff *skb; + int err; + + skb = nlmsg_new(NLMSG_GOODSIZE); + if (skb == NULL) + return ERR_PTR(-ENOBUFS); + + err = ctrl_fill_info(family, pid, seq, 0, skb, cmd); + if (err < 0) { + nlmsg_free(skb); + return ERR_PTR(err); + } + + return skb; +} + +static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = { + [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, + [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING }, +}; + +static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) +{ + struct sk_buff *msg; + struct genl_family *res = NULL; + int err = -EINVAL; + + if (info->attrs[CTRL_ATTR_FAMILY_ID]) { + u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]); + res = genl_family_find_byid(id); + } + + if (info->attrs[CTRL_ATTR_FAMILY_NAME]) { + char name[GENL_NAMSIZ]; + + if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME], + GENL_NAMSIZ) >= GENL_NAMSIZ) + goto errout; + + res = genl_family_find_byname(name); + } + + if (res == NULL) { + err = -ENOENT; + goto errout; + } + + msg = ctrl_build_msg(res, info->snd_pid, info->snd_seq, + CTRL_CMD_NEWFAMILY); + if (IS_ERR(msg)) { + err = PTR_ERR(msg); + goto errout; + } + + err = genlmsg_unicast(msg, info->snd_pid); +errout: + return err; +} + +static int genl_ctrl_event(int event, void *data) +{ + struct sk_buff *msg; + + if (genl_sock == NULL) + return 0; + + switch (event) { + case CTRL_CMD_NEWFAMILY: + case CTRL_CMD_DELFAMILY: + msg = ctrl_build_msg(data, 0, 0, event); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + genlmsg_multicast(msg, 0, GENL_ID_CTRL); + break; + } + + return 0; +} + +static struct genl_ops genl_ctrl_ops = { + .cmd = CTRL_CMD_GETFAMILY, + .doit = ctrl_getfamily, + .dumpit = ctrl_dumpfamily, + .policy = ctrl_policy, +}; + +static struct genl_family genl_ctrl = { + .id = GENL_ID_CTRL, + .name = "nlctrl", + .version = 0x1, + .maxattr = CTRL_ATTR_MAX, + .owner = THIS_MODULE, +}; + +static int __init genl_init(void) +{ + int i, err; + + for (i = 0; i < GENL_FAM_TAB_SIZE; i++) + INIT_LIST_HEAD(&family_ht[i]); + + err = genl_register_family(&genl_ctrl); + if (err < 0) + goto errout; + + err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops); + if (err < 0) + goto errout_register; + + netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV); + genl_sock = netlink_kernel_create(NETLINK_GENERIC, GENL_MAX_ID, + genl_rcv, THIS_MODULE); + if (genl_sock == NULL) { + panic("GENL: Cannot initialize generic netlink\n"); + return -ENOMEM; + } + + return 0; + +errout_register: + genl_unregister_family(&genl_ctrl); +errout: + panic("GENL: Cannot register controller: %d\n", err); + return err; +} + +subsys_initcall(genl_init); + +EXPORT_SYMBOL(genl_sock); +EXPORT_SYMBOL(genl_register_ops); +EXPORT_SYMBOL(genl_unregister_ops); +EXPORT_SYMBOL(genl_register_family); +EXPORT_SYMBOL(genl_unregister_family); |