/** * Convert a character string to a neighbour flag * @arg name name of the flag * * Converts the provided character string specifying a neighbour * flag the corresponding numeric value. * * @return Neighbour flag or a negative value if none was found. */ int rtnl_neigh_str2flag(const char *name) { return __str2type(name, neigh_flags, ARRAY_SIZE(neigh_flags)); }
enum nfnl_log_copy_mode nfnl_log_str2copy_mode(const char *name) { return __str2type(name, copy_modes, ARRAY_SIZE(copy_modes)); }
/** * Send netlink message with control over sendmsg() message header. * @arg handle Netlink handle. * @arg msg Netlink message to be sent. * @arg hdr Sendmsg() message header. * @return Number of characters sent on sucess or a negative error code. */ int nl_sendmsg(struct nl_handle *handle, struct nl_msg *msg, struct msghdr *hdr) { struct nl_cb *cb; int ret; struct iovec iov = { .iov_base = (void *) nlmsg_hdr(msg), .iov_len = nlmsg_hdr(msg)->nlmsg_len, }; hdr->msg_iov = &iov; hdr->msg_iovlen = 1; nlmsg_set_src(msg, &handle->h_local); cb = nl_handle_get_cb(handle); if (cb->cb_set[NL_CB_MSG_OUT]) if (nl_cb_call(cb, NL_CB_MSG_OUT, msg) != NL_PROCEED) return 0; ret = sendmsg(handle->h_fd, hdr, 0); if (ret < 0) return nl_errno(errno); return ret; } /** * Send netlink message. * @arg handle Netlink handle * @arg msg Netlink message to be sent. * @see nl_sendmsg() * @return Number of characters sent on success or a negative error code. */ int nl_send(struct nl_handle *handle, struct nl_msg *msg) { struct sockaddr_nl *dst; struct ucred *creds; struct msghdr hdr = { .msg_name = (void *) &handle->h_peer, .msg_namelen = sizeof(struct sockaddr_nl), }; /* Overwrite destination if specified in the message itself, defaults * to the peer address of the handle. */ dst = nlmsg_get_dst(msg); if (dst->nl_family == AF_NETLINK) hdr.msg_name = dst; /* Add credentials if present. */ creds = nlmsg_get_creds(msg); if (creds != NULL) { char buf[CMSG_SPACE(sizeof(struct ucred))]; struct cmsghdr *cmsg; hdr.msg_control = buf; hdr.msg_controllen = sizeof(buf); cmsg = CMSG_FIRSTHDR(&hdr); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_CREDENTIALS; cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred)); memcpy(CMSG_DATA(cmsg), creds, sizeof(struct ucred)); } return nl_sendmsg(handle, msg, &hdr); } /** * Send netlink message and check & extend header values as needed. * @arg handle Netlink handle. * @arg msg Netlink message to be sent. * * Checks the netlink message \c nlh for completness and extends it * as required before sending it out. Checked fields include pid, * sequence nr, and flags. * * @see nl_send() * @return Number of characters sent or a negative error code. */ int nl_send_auto_complete(struct nl_handle *handle, struct nl_msg *msg) { struct nlmsghdr *nlh; nlh = nlmsg_hdr(msg); if (nlh->nlmsg_pid == 0) nlh->nlmsg_pid = handle->h_local.nl_pid; if (nlh->nlmsg_seq == 0) nlh->nlmsg_seq = handle->h_seq_next++; nlh->nlmsg_flags |= (NLM_F_REQUEST | NLM_F_ACK); if (handle->h_cb->cb_send_ow) return handle->h_cb->cb_send_ow(handle, msg); else return nl_send(handle, msg); } /** * Send simple netlink message using nl_send_auto_complete() * @arg handle Netlink handle. * @arg type Netlink message type. * @arg flags Netlink message flags. * @arg buf Data buffer. * @arg size Size of data buffer. * * Builds a netlink message with the specified type and flags and * appends the specified data as payload to the message. * * @see nl_send_auto_complete() * @return Number of characters sent on success or a negative error code. */ int nl_send_simple(struct nl_handle *handle, int type, int flags, void *buf, size_t size) { int err; struct nl_msg *msg; struct nlmsghdr nlh = { .nlmsg_len = nlmsg_msg_size(0), .nlmsg_type = type, .nlmsg_flags = flags, }; msg = nlmsg_build(&nlh); if (!msg) return nl_errno(ENOMEM); if (buf && size) nlmsg_append(msg, buf, size, 1); err = nl_send_auto_complete(handle, msg); nlmsg_free(msg); return err; } /** @} */ /** * @name Receive * @{ */ /** * Receive netlink message from netlink socket. * @arg handle Netlink handle. * @arg nla Destination pointer for peer's netlink address. * @arg buf Destination pointer for message content. * @arg creds Destination pointer for credentials. * * Receives a netlink message, allocates a buffer in \c *buf and * stores the message content. The peer's netlink address is stored * in \c *nla. The caller is responsible for freeing the buffer allocated * in \c *buf if a positive value is returned. Interruped system calls * are handled by repeating the read. The input buffer size is determined * by peeking before the actual read is done. * * A non-blocking sockets causes the function to return immediately if * no data is available. * * @return Number of octets read, 0 on EOF or a negative error code. */ int nl_recv(struct nl_handle *handle, struct sockaddr_nl *nla, unsigned char **buf, struct ucred **creds) { int n; int flags = MSG_PEEK; struct iovec iov = { .iov_len = 4096, }; struct msghdr msg = { .msg_name = (void *) nla, .msg_namelen = sizeof(sizeof(struct sockaddr_nl)), .msg_iov = &iov, .msg_iovlen = 1, .msg_control = NULL, .msg_controllen = 0, .msg_flags = 0, }; struct cmsghdr *cmsg; iov.iov_base = *buf = calloc(1, iov.iov_len); if (handle->h_flags & NL_SOCK_PASSCRED) { msg.msg_controllen = CMSG_SPACE(sizeof(struct ucred)); msg.msg_control = calloc(1, msg.msg_controllen); } retry: if ((n = recvmsg(handle->h_fd, &msg, flags)) <= 0) { if (!n) goto abort; else if (n < 0) { if (errno == EINTR) goto retry; else if (errno == EAGAIN) goto abort; else { free(msg.msg_control); free(*buf); return nl_error(errno, "recvmsg failed"); } } } if (iov.iov_len < n) { /* Provided buffer is not long enough, enlarge it * and try again. */ iov.iov_len *= 2; iov.iov_base = *buf = realloc(*buf, iov.iov_len); goto retry; } else if (msg.msg_flags & MSG_CTRUNC) { msg.msg_controllen *= 2; msg.msg_control = realloc(msg.msg_control, msg.msg_controllen); goto retry; } else if (flags != 0) { /* Buffer is big enough, do the actual reading */ flags = 0; goto retry; } if (msg.msg_namelen != sizeof(struct sockaddr_nl)) { free(msg.msg_control); free(*buf); return nl_error(EADDRNOTAVAIL, "socket address size mismatch"); } for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_CREDENTIALS) { *creds = calloc(1, sizeof(struct ucred)); memcpy(*creds, CMSG_DATA(cmsg), sizeof(struct ucred)); break; } } free(msg.msg_control); return n; abort: free(msg.msg_control); free(*buf); return 0; } /** * Receive a set of messages from a netlink socket. * @arg handle netlink handle * @arg cb set of callbacks to control the behaviour. * * Repeatedly calls nl_recv() and parses the messages as netlink * messages. Stops reading if one of the callbacks returns * NL_EXIT or nl_recv returns either 0 or a negative error code. * * A non-blocking sockets causes the function to return immediately if * no data is available. * * @return 0 on success or a negative error code from nl_recv(). */ int nl_recvmsgs(struct nl_handle *handle, struct nl_cb *cb) { int n, err = 0; unsigned char *buf = NULL; struct nlmsghdr *hdr; struct sockaddr_nl nla = {0}; struct nl_msg *msg = NULL; struct ucred *creds = NULL; continue_reading: if (cb->cb_recv_ow) n = cb->cb_recv_ow(handle, &nla, &buf, &creds); else n = nl_recv(handle, &nla, &buf, &creds); if (n <= 0) return n; NL_DBG(3, "recvmsgs(%p): Read %d bytes\n", handle, n); hdr = (struct nlmsghdr *) buf; while (nlmsg_ok(hdr, n)) { NL_DBG(3, "recgmsgs(%p): Processing valid message...\n", handle); nlmsg_free(msg); msg = nlmsg_convert(hdr); if (!msg) { err = nl_errno(ENOMEM); goto out; } nlmsg_set_proto(msg, handle->h_proto); nlmsg_set_src(msg, &nla); if (creds) nlmsg_set_creds(msg, creds); /* Raw callback is the first, it gives the most control * to the user and he can do his very own parsing. */ if (cb->cb_set[NL_CB_MSG_IN]) { err = nl_cb_call(cb, NL_CB_MSG_IN, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } /* Sequence number checking. The check may be done by * the user, otherwise a very simple check is applied * enforcing strict ordering */ if (cb->cb_set[NL_CB_SEQ_CHECK]) { err = nl_cb_call(cb, NL_CB_SEQ_CHECK, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else if (hdr->nlmsg_seq != handle->h_seq_expect) { if (cb->cb_set[NL_CB_INVALID]) { err = nl_cb_call(cb, NL_CB_INVALID, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } if (hdr->nlmsg_type == NLMSG_DONE || hdr->nlmsg_type == NLMSG_ERROR || hdr->nlmsg_type == NLMSG_NOOP || hdr->nlmsg_type == NLMSG_OVERRUN) { /* We can't check for !NLM_F_MULTI since some netlink * users in the kernel are broken. */ handle->h_seq_expect++; NL_DBG(3, "recvmsgs(%p): Increased expected " \ "sequence number to %d\n", handle, handle->h_seq_expect); } /* Other side wishes to see an ack for this message */ if (hdr->nlmsg_flags & NLM_F_ACK) { if (cb->cb_set[NL_CB_SEND_ACK]) { err = nl_cb_call(cb, NL_CB_SEND_ACK, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else { /* FIXME: implement */ } } /* messages terminates a multpart message, this is * usually the end of a message and therefore we slip * out of the loop by default. the user may overrule * this action by skipping this packet. */ if (hdr->nlmsg_type == NLMSG_DONE) { if (cb->cb_set[NL_CB_FINISH]) { err = nl_cb_call(cb, NL_CB_FINISH, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } err = 0; goto out; } /* Message to be ignored, the default action is to * skip this message if no callback is specified. The * user may overrule this action by returning * NL_PROCEED. */ else if (hdr->nlmsg_type == NLMSG_NOOP) { if (cb->cb_set[NL_CB_SKIPPED]) { err = nl_cb_call(cb, NL_CB_SKIPPED, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto skip; } /* Data got lost, report back to user. The default action is to * quit parsing. The user may overrule this action by retuning * NL_SKIP or NL_PROCEED (dangerous) */ else if (hdr->nlmsg_type == NLMSG_OVERRUN) { if (cb->cb_set[NL_CB_OVERRUN]) { err = nl_cb_call(cb, NL_CB_OVERRUN, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } /* Message carries a nlmsgerr */ else if (hdr->nlmsg_type == NLMSG_ERROR) { struct nlmsgerr *e = nlmsg_data(hdr); if (hdr->nlmsg_len < nlmsg_msg_size(sizeof(*e))) { /* Truncated error message, the default action * is to stop parsing. The user may overrule * this action by returning NL_SKIP or * NL_PROCEED (dangerous) */ if (cb->cb_set[NL_CB_INVALID]) { err = nl_cb_call(cb, NL_CB_INVALID, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } else if (e->error) { /* Error message reported back from kernel. */ if (cb->cb_err) { err = cb->cb_err(&nla, e, cb->cb_err_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) { nl_error(-e->error, "Netlink Error"); err = e->error; goto out; } } else { nl_error(-e->error, "Netlink Error"); err = e->error; goto out; } } else if (cb->cb_set[NL_CB_ACK]) { /* ACK */ err = nl_cb_call(cb, NL_CB_ACK, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } } else { /* Valid message (not checking for MULTIPART bit to * get along with broken kernels. NL_SKIP has no * effect on this. */ if (cb->cb_set[NL_CB_VALID]) { err = nl_cb_call(cb, NL_CB_VALID, msg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } } skip: hdr = nlmsg_next(hdr, &n); } nlmsg_free(msg); free(buf); free(creds); buf = NULL; msg = NULL; creds = NULL; /* Multipart message not yet complete, continue reading */ goto continue_reading; out: nlmsg_free(msg); free(buf); free(creds); return err; } /** * Receive a set of message from a netlink socket using handlers in nl_handle. * @arg handle netlink handle * * Calls nl_recvmsgs() with the handlers configured in the netlink handle. */ int nl_recvmsgs_def(struct nl_handle *handle) { if (handle->h_cb->cb_recvmsgs_ow) return handle->h_cb->cb_recvmsgs_ow(handle, handle->h_cb); else return nl_recvmsgs(handle, handle->h_cb); } static int ack_wait_handler(struct nl_msg *msg, void *arg) { return NL_EXIT; } /** * Wait for ACK. * @arg handle netlink handle * @pre The netlink socket must be in blocking state. * * Waits until an ACK is received for the latest not yet acknowledged * netlink message. */ int nl_wait_for_ack(struct nl_handle *handle) { int err; struct nl_cb *cb = nl_cb_clone(nl_handle_get_cb(handle)); nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_wait_handler, NULL); err = nl_recvmsgs(handle, cb); nl_cb_destroy(cb); return err; } /** @} */ /** * @name Netlink Family Translations * @{ */ static struct trans_tbl nlfamilies[] = { __ADD(NETLINK_ROUTE,route) __ADD(NETLINK_W1,w1) __ADD(NETLINK_USERSOCK,usersock) __ADD(NETLINK_FIREWALL,firewall) __ADD(NETLINK_INET_DIAG,inetdiag) __ADD(NETLINK_NFLOG,nflog) __ADD(NETLINK_XFRM,xfrm) __ADD(NETLINK_SELINUX,selinux) __ADD(NETLINK_ISCSI,iscsi) __ADD(NETLINK_AUDIT,audit) __ADD(NETLINK_FIB_LOOKUP,fib_lookup) __ADD(NETLINK_CONNECTOR,connector) __ADD(NETLINK_NETFILTER,netfilter) __ADD(NETLINK_IP6_FW,ip6_fw) __ADD(NETLINK_DNRTMSG,dnrtmsg) __ADD(NETLINK_KOBJECT_UEVENT,kobject_uevent) __ADD(NETLINK_GENERIC,generic) }; /** * Convert netlink family to character string. * @arg family Netlink family. * @arg buf Destination buffer. * @arg size Size of destination buffer. * * Converts a netlink family to a character string and stores it in * the specified destination buffer. * * @return The destination buffer or the family encoded in hexidecimal * form if no match was found. */ char * nl_nlfamily2str(int family, char *buf, size_t size) { return __type2str(family, buf, size, nlfamilies, ARRAY_SIZE(nlfamilies)); } /** * Convert character string to netlink family. * @arg name Name of netlink family. * * Converts the provided character string specifying a netlink * family to the corresponding numeric value. * * @return Numeric netlink family or a negative value if no match was found. */ int nl_str2nlfamily(const char *name) { return __str2type(name, nlfamilies, ARRAY_SIZE(nlfamilies)); }
/** * Convert a character string to a neighbour state * @arg name Name of cscope * * Converts the provided character string specifying a neighbour * state the corresponding numeric value. * * @return Neighbour state or a negative value if none was found. */ int rtnl_neigh_str2state(const char *name) { return __str2type(name, neigh_states, ARRAY_SIZE(neigh_states)); }
unsigned int nfnl_str2inet_hook(const char *name) { return __str2type(name, nfnl_inet_hooks, ARRAY_SIZE(nfnl_inet_hooks)); }
int nfnl_ct_str2tcp_state(const char *name) { return __str2type(name, tcp_states, ARRAY_SIZE(tcp_states)); }
/** * Convert inet diag timer string to int. * @arg name inetdiag timer string * * @return the int representation of the timer string or a negative error code. */ int idiagnl_str2timer(const char *name) { return __str2type(name, idiag_timers, ARRAY_SIZE(idiag_timers)); }
int nl_str2ether_proto(const char *name) { return __str2type(name, ether_protos, ARRAY_SIZE(ether_protos)); }
/** * Convert a string to a CBQ OVL strategy * @arg name CBQ OVL stragegy name * * Converts a CBQ OVL stragegy name to it's corresponding CBQ OVL strategy * type. Returns the type or -1 if none was found. */ int nl_str2ovl_strategy(const char *name) { return __str2type(name, ovl_strategies, ARRAY_SIZE(ovl_strategies)); }
/** * Convert inet diag socket state string to int. * @arg name inetdiag socket state string * * @return the int representation of the socket state strign or a negative error * code. */ int idiagnl_str2state(const char *name) { return __str2type(name, idiag_states, ARRAY_SIZE(idiag_states)); }
int nl_str2rtntype(const char *name) { return __str2type(name, rtntypes, ARRAY_SIZE(rtntypes)); }
int rtnl_str2scope(const char *name) { return __str2type(name, scopes, ARRAY_SIZE(scopes)); }
uint8_t rtnl_link_inet6_str2addrgenmode(const char *mode) { return (uint8_t) __str2type(mode, inet6_addr_gen_mode, ARRAY_SIZE(inet6_addr_gen_mode)); }
int nl_str2nlfamily(const char *name) { return __str2type(name, nlfamilies, ARRAY_SIZE(nlfamilies)); }
int nfnl_queue_str2copy_mode(const char *name) { return __str2type(name, copy_modes, ARRAY_SIZE(copy_modes)); }
int nl_str2llproto(const char *name) { return __str2type(name, llprotos, ARRAY_SIZE(llprotos)); }
/** * Send a netlink message. * @arg handle netlink handle * @arg nmsg netlink message * @return see sendmsg(2) */ int nl_send(struct nl_handle *handle, struct nlmsghdr *nmsg) { struct nl_cb *cb; struct iovec iov = { .iov_base = (void *) nmsg, .iov_len = nmsg->nlmsg_len, }; struct msghdr msg = { .msg_name = (void *) &handle->h_peer, .msg_namelen = sizeof(struct sockaddr_nl), .msg_iov = &iov, .msg_iovlen = 1, }; cb = &handle->h_cb; if (cb->cb_msg_out) if (cb->cb_msg_out(nmsg, cb->cb_msg_out_arg) != NL_PROCEED) return 0; return sendmsg(handle->h_fd, &msg, 0); } /** * Send a netlink message and check & extend needed header values * @arg handle netlink handle * @arg nmsg netlink message * * Checks the netlink message \c nmsg for completness and extends it * as required before sending it out. Checked fields include pid, * sequence nr, and flags. * * @return see sendmsg(2) */ int nl_send_auto_complete(struct nl_handle *handle, struct nlmsghdr *nmsg) { if (nmsg->nlmsg_pid == 0) nmsg->nlmsg_pid = handle->h_local.nl_pid; if (nmsg->nlmsg_seq == 0) nmsg->nlmsg_seq = handle->h_seq_next++; nmsg->nlmsg_flags |= (NLM_F_REQUEST | NLM_F_ACK); if (handle->h_cb.cb_send_ow) return handle->h_cb.cb_send_ow(handle, nmsg); else return nl_send(handle, nmsg); } /** * Send a netlink request message * @arg handle netlink handle * @arg type message type * @arg flags message flags * * Fills out a netlink request message and sends it out using * nl_send_auto_complete() * * @return See sendmsg(2) */ int nl_request(struct nl_handle *handle, int type, int flags) { struct nlmsghdr n = { .nlmsg_len = NLMSG_LENGTH(0), .nlmsg_type = type, .nlmsg_flags = flags, }; return nl_send_auto_complete(handle, &n); } /** * Send a netlink request message with data. * @arg handle netlink handle * @arg type message type * @arg flags message flags * @arg buf data buffer * @arg len length of data * * Fills out a netlink request message, appends the data to the tail * and sends it out using nl_send_auto_complete(). * * @return See sendmsg(2) */ int nl_request_with_data(struct nl_handle *handle, int type, int flags, unsigned char *buf, size_t len) { int err = 0; struct nl_msg *m; struct nlmsghdr n = { .nlmsg_len = NLMSG_LENGTH(0), .nlmsg_type = type, .nlmsg_flags = flags, }; m = nl_msg_build(&n); nl_msg_append_raw(m, buf, len); err = nl_send_auto_complete(handle, m->nmsg); nl_msg_free(m); return err; } /** @} */ /** * @name Receive * @{ */ /** * Receive a netlink message from netlink socket. * @arg handle netlink handle * @arg nla target pointer for peer's netlink address * @arg buf target pointer for message content. * * Receives a netlink message, allocates a buffer in \c *buf and * stores the message content. The peer's netlink address is stored * in \c *nla. The caller is responsible for freeing the buffer allocated * in \c *buf if a positive value is returned. Interruped system calls * are handled by repeating the read. The input buffer size is determined * by peeking before the actual read is done. * * A non-blocking sockets causes the function to return immediately if * no data is available. * * @return Number of octets read, 0 on EOF or a negative error code. */ int nl_recv(struct nl_handle *handle, struct sockaddr_nl *nla, unsigned char **buf) { int n; int flags = MSG_PEEK; struct iovec iov = { .iov_len = 4096, }; struct msghdr msg = { .msg_name = (void *) nla, .msg_namelen = sizeof(sizeof(struct sockaddr_nl)), .msg_iov = &iov, .msg_iovlen = 1, .msg_control = NULL, .msg_controllen = 0, .msg_flags = 0, }; iov.iov_base = *buf = calloc(1, iov.iov_len); retry: if ((n = recvmsg(handle->h_fd, &msg, flags)) <= 0) { if (!n) goto abort; else if (n < 0) { if (errno == EINTR) goto retry; else if (errno == EAGAIN) goto abort; else { free(*buf); return nl_error(errno, "recvmsg failed"); } } } if (iov.iov_len < n) { /* Provided buffer is not long enough, enlarge it * and try again. */ iov.iov_len *= 2; iov.iov_base = *buf = realloc(*buf, iov.iov_len); goto retry; } else if (flags != 0) { /* Buffer is big enough, do the actual reading */ flags = 0; goto retry; } if (msg.msg_namelen != sizeof(struct sockaddr_nl)) { free(*buf); return nl_error(EADDRNOTAVAIL, "socket address size mismatch"); } return n; abort: free(*buf); return 0; } /** * Receive a set of messages from a netlink socket. * @arg handle netlink handle * @arg cb set of callbacks to control the behaviour. * * Repeatedly calls nl_recv() and parses the messages as netlink * messages. Stops reading if one of the callbacks returns * NL_EXIT or nl_recv returns either 0 or a negative error code. * * A non-blocking sockets causes the function to return immediately if * no data is available. * * @return 0 on success or a negative error code from nl_recv(). * @see \ref Handlers */ int nl_recvmsgs(struct nl_handle *handle, struct nl_cb *cb) { int n, err = 0; unsigned char *buf = NULL; struct nlmsghdr *hdr; struct sockaddr_nl nla = {0}; continue_reading: if (cb->cb_recv_ow) n = cb->cb_recv_ow(handle, &nla, &buf); else n = nl_recv(handle, &nla, &buf); if (n <= 0) return n; hdr = (struct nlmsghdr *) buf; while (NLMSG_OK(hdr, n)) { /* Raw callback is the first, it gives the most control * to the user and he can do his very own parsing. */ if (cb->cb_msg_in) { err = cb->cb_msg_in(&nla, hdr, cb->cb_msg_in_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } /* Sequence number checking. The check may be done by * the user, otherwise a very simple check is applied * enforcing strict ordering */ if (cb->cb_seq_check) { err = cb->cb_seq_check(&nla, hdr, cb->cb_seq_check_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else if (hdr->nlmsg_seq != handle->h_seq_expect) { if (cb->cb_invalid) { err = cb->cb_invalid(&nla, hdr, cb->cb_invalid_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } if (hdr->nlmsg_type == NLMSG_DONE || hdr->nlmsg_type == NLMSG_ERROR || hdr->nlmsg_type == NLMSG_NOOP || hdr->nlmsg_type == NLMSG_OVERRUN) { /* We can't check for !NLM_F_MULTI since some netlink * users in the kernel are broken. */ handle->h_seq_expect++; } /* Other side wishes to see an ack for this message */ if (hdr->nlmsg_flags & NLM_F_ACK) { if (cb->cb_send_ack) { err = cb->cb_send_ack(&nla, hdr, cb->cb_send_ack_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else { /* FIXME: implement */ } } /* messages terminates a multpart message, this is * usually the end of a message and therefore we slip * out of the loop by default. the user may overrule * this action by skipping this packet. */ if (hdr->nlmsg_type == NLMSG_DONE) { if (cb->cb_finish) { err = cb->cb_finish(&nla, hdr, cb->cb_finish_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } goto out; } /* Message to be ignored, the default action is to * skip this message if no callback is specified. The * user may overrule this action by returning * NL_PROCEED. */ else if (hdr->nlmsg_type == NLMSG_NOOP) { if (cb->cb_skipped) { err = cb->cb_skipped(&nla, hdr, cb->cb_skipped_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto skip; } /* Data got lost, report back to user. The default action is to * quit parsing. The user may overrule this action by retuning * NL_SKIP or NL_PROCEED (dangerous) */ else if (hdr->nlmsg_type == NLMSG_OVERRUN) { if (cb->cb_overrun) { err = cb->cb_overrun(&nla, hdr, cb->cb_overrun_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } /* Message carries a nlmsgerr */ else if (hdr->nlmsg_type == NLMSG_ERROR) { struct nlmsgerr *e = (struct nlmsgerr*) NLMSG_DATA(hdr); if (hdr->nlmsg_len < NLMSG_LENGTH(sizeof(*e))) { /* Truncated error message, the default action * is to stop parsing. The user may overrule * this action by returning NL_SKIP or * NL_PROCEED (dangerous) */ if (cb->cb_invalid) { err = cb->cb_invalid(&nla, hdr, cb->cb_invalid_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } else if (e->error) { /* Error message reported back from kernel. */ if (cb->cb_error) { err = cb->cb_error(&nla, e, cb->cb_error_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } else goto out; } else if (cb->cb_ack) { /* ACK */ err = cb->cb_ack(&nla, hdr, cb->cb_ack_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } } else { /* Valid message (not checking for MULTIPART bit to * get along with broken kernels. NL_SKIP has no * effect on this. */ if (cb->cb_valid) { err = cb->cb_valid(&nla, hdr, cb->cb_valid_arg); if (err == NL_SKIP) goto skip; else if (err == NL_EXIT || err < 0) goto out; } } skip: hdr = NLMSG_NEXT(hdr, n); } if (buf) { free(buf); buf = NULL; } /* Multipart message not yet complete, continue reading */ goto continue_reading; out: if (buf) free(buf); return err; } /** * Receive a set of message from a netlink socket using handlers in nl_handle. * @arg handle netlink handle * * Calls nl_recvmsgs() with the handlers configured in the netlink handle. * * @see \ref Handlers */ int nl_recvmsgs_def(struct nl_handle *handle) { if (handle->h_cb.cb_recvmsgs_ow) return handle->h_cb.cb_recvmsgs_ow(handle, &handle->h_cb); else return nl_recvmsgs(handle, &handle->h_cb); } static int ack_wait_handler(struct sockaddr_nl *who, struct nlmsghdr *n, void *arg) { return NL_EXIT; } /** * Wait for ACK. * @arg handle netlink handle * @pre The netlink socket must be in blocking state. * * Waits until an ACK is received for the latest not yet acknoledged * netlink message. */ int nl_wait_for_ack(struct nl_handle *handle) { struct nl_cb cb; memcpy(&cb, &handle->h_cb, sizeof(cb)); cb.cb_ack = ack_wait_handler; return nl_recvmsgs(handle, &cb); } /** @} */ /** * @name Netlink Family Translations * @{ */ static struct trans_tbl nlfamilies[] = { __ADD(NETLINK_ROUTE,route) __ADD(NETLINK_SKIP,skip) __ADD(NETLINK_USERSOCK,usersock) __ADD(NETLINK_FIREWALL,firewall) __ADD(NETLINK_TCPDIAG,tcpdiag) __ADD(NETLINK_NFLOG,nflog) __ADD(NETLINK_XFRM,xfrm) __ADD(NETLINK_SELINUX,selinux) __ADD(NETLINK_ARPD,arpd) __ADD(NETLINK_AUDIT,audit) __ADD(NETLINK_ROUTE6,route6) __ADD(NETLINK_IP6_FW,ip6_fw) __ADD(NETLINK_DNRTMSG,dnrtmsg) __ADD(NETLINK_KOBJECT_UEVENT,kobject_uevent) __ADD(NETLINK_TAPBASE,tapbase) }; /** * Convert a netlink family to a character string (Reentrant). * @arg family netlink family * @arg buf destination buffer * @arg len buffer length * * Converts a netlink family to a character string and stores it in * the specified destination buffer. * * @return The destination buffer or the family encoded in hexidecimal * form if no match was found. */ char * nl_nlfamily2str_r(int family, char *buf, size_t len) { return __type2str_r(family, buf, len, nlfamilies, ARRAY_SIZE(nlfamilies)); } /** * Convert a netlink family to a character string. * @arg family netlink family * * Converts a netlink family to a character string and stores it in a * static buffer. * * @return A static buffer or the family encoded in hexidecimal * form if no match was found. * @attention This funnction is NOT thread safe. */ char * nl_nlfamily2str(int family) { static char buf[32]; memset(buf, 0, sizeof(buf)); return __type2str_r(family, buf, sizeof(buf), nlfamilies, ARRAY_SIZE(nlfamilies)); } /** * Convert a character string to a netlink family * @arg name name of netlink family * * Converts the provided character string specifying a netlink * family to the corresponding numeric value. * * @return Netlink family negative value if none was found. */ int nl_str2nlfamily(const char *name) { return __str2type(name, nlfamilies, ARRAY_SIZE(nlfamilies)); }
/** * Transform a character string into a policer type number * @arg name policer type name * * Transform the provided character string specifying a policer * type into the corresponding numeric value * * @return Policer type number or a negative value. */ int nl_str2police(const char *name) { return __str2type(name, police_types, ARRAY_SIZE(police_types)); }
unsigned int nfnl_str2verdict(const char *name) { return __str2type(name, nfnl_verdicts, ARRAY_SIZE(nfnl_verdicts)); }