From 38c416988fe7956f377f064e98423d8f0f30eaea Mon Sep 17 00:00:00 2001 From: dimitri staessens Date: Tue, 19 Apr 2016 19:22:03 +0200 Subject: shim-udp: flow allocation added This implements the API for flow allocation. The shims currently does the following. The shim IPCP binds to an interface (IP address) and listens for flow allocation requests on UDP port 0x0D1F (3359), referenced as the listen port (lp). It will treat any datagram received on lp as a flow allocation request. Upon receiving an allocation request IRM_MSG_CODE__IPCP_FLOW_ALLOC from the IRMd, the shim IPCP will bind a UDP socket to a port (cp) allocated by the host OS. From that port it will send a UDP packet containing the destination ap_name to server_host:lp and wait for a response. Upon reception of a packet on server_host:lp, the shim_IPCP creates a UDP socket for the flow with a port set by the host os (sp), binds to it and echoes the received datagram back from server_host:sp to client_host:cp. It will also notify the IRMd of an incoming flow allocation request IRM_MSG_CODE__IPCP_FLOW_REQ_ARR, with as src_ap_name ("John Day"). It will get the port_id as a return value of that message and create a flow with status FLOW_PENDING with that port_id. If the server responds negatively to the flow allocation request (i.e. the shim IPCP on the server side receives a IRM_MSG_CODE__IPCP_FLOW_ALLOC_RESPONSE with a response != 0, it will delete the pending flow. If response == 0, it will set the status to FLOW_ALLOCATED. On the client machine the IPCP will learn sp upon reception of the echoed datagram. It will then create a flow with the port_id it received with the message from the IRMd and set it to ALLOCATED. Pending implementation: DNS support, this PR only supports local flows on the loopback adapter 127.0.0.1. A thread to listen for the echoed message, to avoid the entire IPCP to block when the echoed message is lost. This PR compiles but is untested pending necessary implementations elsewhere in the stack. --- src/ipcpd/shim-udp/main.c | 294 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 287 insertions(+), 7 deletions(-) (limited to 'src/ipcpd/shim-udp') diff --git a/src/ipcpd/shim-udp/main.c b/src/ipcpd/shim-udp/main.c index df731490..66513b02 100644 --- a/src/ipcpd/shim-udp/main.c +++ b/src/ipcpd/shim-udp/main.c @@ -43,10 +43,23 @@ #include #include +#include "irmd_messages.pb-c.h" + +typedef IrmMsg irm_msg_t; + +#include "ipcpd_messages.pb-c.h" + +typedef IpcpMsg ipcp_msg_t; + #define THIS_TYPE IPCP_SHIM_UDP +#define LISTEN_PORT htons(0x0D1F) +#define SHIM_UDP_BUF_SIZE 256 #define shim_data(type) ((struct ipcp_udp_data *) type->data) +#define local_ip (((struct ipcp_udp_data *) \ + _ipcp->data)->s_saddr.sin_addr.s_addr) + /* global for trapping signal */ int irmd_pid; @@ -64,16 +77,16 @@ struct ipcp_udp_data { uint32_t ip_addr; uint32_t dns_addr; + /* listen server */ + struct sockaddr_in s_saddr; + int s_fd; + pthread_mutex_t lock; }; struct udp_flow { /* FLOW MUST BE FIRST !!!! */ flow_t flow; - - uint16_t localport; - - struct sockaddr_in * remote; int fd; }; @@ -131,10 +144,117 @@ struct ipcp_udp_data * ipcp_udp_data_create(char * ap_name, return udp_data; } +void * ipcp_udp_listener() +{ + char buf[SHIM_UDP_BUF_SIZE]; + int n = 0; + + struct sockaddr_in f_saddr; + struct sockaddr_in c_saddr; + struct hostent * hostp; + struct udp_flow * flow; + int sfd = shim_data(_ipcp)->s_fd; + + irm_msg_t msg = IRM_MSG__INIT; + irm_msg_t * ret_msg ; + + while (true) { + flow = malloc(sizeof *flow); + if (flow == NULL) + continue; + n = sizeof c_saddr; + n = recvfrom(sfd, buf, SHIM_UDP_BUF_SIZE, 0, + (struct sockaddr *) &c_saddr, (unsigned *) &n); + if (n < 0) + continue; + + /* flow alloc request from other host */ + hostp = gethostbyaddr((const char *)&c_saddr.sin_addr.s_addr, + sizeof(c_saddr.sin_addr.s_addr), AF_INET); + if (hostp == NULL) + continue; + + /* create a new socket for the server */ + + flow->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (flow->fd == -1) { + free(flow); + continue; + } + + memset((char *)&f_saddr, 0, sizeof f_saddr); + f_saddr.sin_family = AF_INET; + f_saddr.sin_addr.s_addr = local_ip; + + /* + * FIXME: we could have a port dedicated per registered AP + * Not that critical for UDP, but will be for LLC + */ + + f_saddr.sin_port = 0; + + /* at least try to get the packet on the wire */ + while (sendto(flow->fd, buf, n, 0, + (struct sockaddr *) &c_saddr, sizeof c_saddr) < 0) + ; + + /* + * store the remote address in the file descriptor + * this avoids having to store the sockaddr_in in + * the flow structure + */ + + if (connect(flow->fd, + (struct sockaddr *)&c_saddr, sizeof c_saddr) < 0) { + close(flow->fd); + free(flow); + continue; + } + + + /* GERONIMOO */ + + msg.code = IRM_MSG_CODE__IPCP_FLOW_REQ_ARR; + msg.ap_name = "John Day"; + msg.ae_name = ""; /* no AE */ + msg.has_reg_ap_id = true; + msg.reg_ap_id = ipcp_data_get_reg_ap_id(_ipcp->data, buf); + + ret_msg = send_recv_irm_msg(&msg); + if (ret_msg == NULL) { + LOG_ERR("Could not send message to IRM."); + close(flow->fd); + free(flow); + continue; + } + + if (!ret_msg->has_port_id) { + LOG_ERR("Didn't get port_id."); + free(ret_msg); + close(flow->fd); + free(flow); + continue; + } + + flow->flow.port_id = ret_msg->port_id; + flow->flow.oflags = FLOW_O_DEFAULT; + flow->flow.state = FLOW_PENDING; + + if(ipcp_data_add_flow(_ipcp->data, (flow_t *) flow)) { + LOG_DBGF("Could not add flow."); + free(ret_msg); + close(flow->fd); + free(flow); + continue; + } + } +} + int ipcp_udp_bootstrap(struct dif_config * conf) { char ipstr[INET_ADDRSTRLEN]; char dnsstr[INET_ADDRSTRLEN]; + pthread_t handler; if (conf->type != THIS_TYPE) { LOG_ERR("Config doesn't match IPCP type."); @@ -162,6 +282,27 @@ int ipcp_udp_bootstrap(struct dif_config * conf) shim_data(_ipcp)->ip_addr = conf->ip_addr; shim_data(_ipcp)->dns_addr = conf->dns_addr; + /* UDP listen server */ + + if ((shim_data(_ipcp)->s_fd = + socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) { + LOG_DBGF("Can't create socket."); + return -1; + } + + shim_data(_ipcp)->s_saddr.sin_family = AF_INET; + shim_data(_ipcp)->s_saddr.sin_addr.s_addr = conf->ip_addr; + shim_data(_ipcp)->s_saddr.sin_port = LISTEN_PORT; + + if (bind(shim_data(_ipcp)->s_fd, + (struct sockaddr *)&shim_data(_ipcp)->s_saddr, + sizeof shim_data(_ipcp)->s_saddr ) < 0) { + LOG_ERR("Couldn't bind to %s.", ipstr); + return -1; + } + + pthread_create(&handler, NULL, ipcp_udp_listener, NULL); + _ipcp->state = IPCP_ENROLLED; LOG_DBG("Bootstrapped shim IPCP over UDP %s-%d.", @@ -196,7 +337,6 @@ int ipcp_udp_ap_unreg(uint32_t reg_ap_id) { char * name = strdup(ipcp_data_get_reg_ap_name(_ipcp->data, reg_ap_id)); - LOG_DBG("Unregistering %s.", name); ipcp_data_del_reg_entry(_ipcp->data, reg_ap_id); @@ -214,11 +354,151 @@ int ipcp_udp_flow_alloc(uint32_t port_id, char * src_ae_name, struct qos_spec * qos) { - return 0; + char buf[SHIM_UDP_BUF_SIZE]; + struct udp_flow * flow = NULL; + struct sockaddr_in l_saddr; + struct sockaddr_in r_saddr; + int n; + + irm_msg_t msg = IRM_MSG__INIT; + irm_msg_t * ret_msg = NULL; + + if (dst_ap_name == NULL || src_ap_name == NULL || src_ae_name == NULL) + return -1; + + LOG_DBG("Received flow allocation request from %s to %s.", + src_ap_name, dst_ap_name); + + if (strlen(dst_ap_name) > 255 + || strlen(src_ap_name) > 255 + || strlen(src_ae_name) > 255) { + LOG_ERR("Name too long for this shim."); + return -1; + } + + if (qos != NULL) + LOG_DBGF("QoS requested. UDP/IP can't do that."); + + flow = malloc (sizeof *flow); + if (flow == NULL) + return -1; + + flow->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (flow->fd == -1) { + free(flow); + return -1; + } + + /* this socket is for the flow */ + memset((char *)&l_saddr, 0, sizeof l_saddr); + l_saddr.sin_family = AF_INET; + l_saddr.sin_addr.s_addr = local_ip; + l_saddr.sin_port = 0; + + if (bind(flow->fd, (struct sockaddr *) &l_saddr, sizeof l_saddr) < 0) { + char ipstr[INET_ADDRSTRLEN]; + inet_ntop(AF_INET, + &l_saddr.sin_addr.s_addr, + ipstr, + INET_ADDRSTRLEN); + close(flow->fd); + free(flow); + return -1; + } + + /* get the remote IPv4 address using dns */ + /* FIXME: use calls to specify DDNS server */ + +#define IP_ADDR 0x7f000001; /* localhost */ + + LOG_MISSING; + + memset((char *)&r_saddr, 0, sizeof r_saddr); + r_saddr.sin_family = AF_INET; + /* FIXME: pull in correct IP address */ + r_saddr.sin_addr.s_addr = IP_ADDR; /* FIXME */ + r_saddr.sin_port = LISTEN_PORT; + + /* at least try to get the packet on the wire */ + while (sendto(flow->fd, dst_ap_name, n, 0, + (struct sockaddr *) &r_saddr, sizeof r_saddr) < 0) + + /* wait for the echo from the server */ + /* FIXME: do this in a different thread not to block the entire shim */ + n = sizeof r_saddr; + n = recvfrom(flow->fd, buf, SHIM_UDP_BUF_SIZE, 0, + (struct sockaddr *) &r_saddr, (unsigned *) &n); + + flow->flow.port_id = port_id; + flow->flow.oflags = FLOW_O_DEFAULT; + flow->flow.state = FLOW_ALLOCATED; + + /* + * store the remote address in the file descriptor + * this avoids having to store the sockaddr_in in + * the flow structure + */ + + if (connect(flow->fd, + (struct sockaddr *)&r_saddr, sizeof r_saddr) < 0) { + close(flow->fd); + free(flow); + return -1; + } + + /* add flow to the list */ + + pthread_mutex_lock(&_ipcp->data->flow_lock); + + if(ipcp_data_add_flow(_ipcp->data, (flow_t *)flow)) { + LOG_DBGF("Could not add flow."); + pthread_mutex_unlock(&_ipcp->data->flow_lock); + close(flow->fd); + free(flow); + return -1; + } + + pthread_mutex_unlock(&_ipcp->data->flow_lock); + + /* tell IRMd that flow allocation worked */ + /* well,there is no flow allocation */ + + msg.code = IRM_MSG_CODE__IPCP_FLOW_ALLOC_REPLY; + msg.has_port_id = true; + msg.port_id = flow->flow.port_id; + msg.has_response = true; + msg.response = 0; + + ret_msg = send_recv_irm_msg(&msg); + if (ret_msg == NULL) { + close (flow->fd); + ipcp_data_del_flow(_ipcp->data, flow->flow.port_id); + return -1; + } + + return flow->fd; } int ipcp_udp_flow_alloc_resp(uint32_t port_id, - int result) + int response) { + struct udp_flow * flow = (struct udp_flow *) ipcp_data_find_flow( + _ipcp->data, port_id); + if (flow == NULL) { + return -1; + } + + if (response) { + ipcp_data_del_flow(_ipcp->data, port_id); + return 0; + } + + /* awaken pending flow */ + + if (flow->flow.state != FLOW_PENDING) + return -1; + + flow->flow.state = FLOW_ALLOCATED; + return 0; } -- cgit v1.2.3