examples/ip_pipeline/conn.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2018 Intel Corporation
   3  */
   4
   5 #include <string.h>
   6 #include <stdlib.h>
   7 #include <stdio.h>
   8 #include <unistd.h>
   9 #include <sys/types.h>
  10
  11 #define __USE_GNU
  12 #include <sys/socket.h>
  13
  14 #include <sys/epoll.h>
  15 #include <netinet/in.h>
  16 #include <arpa/inet.h>
  17 #include <errno.h>
  18
  19 #include "conn.h"
  20
  21 #define MSG_CMD_TOO_LONG "Command too long."
  22
  23 struct conn {
  24         char *welcome;
  25         char *prompt;
  26         char *buf;
  27         char *msg_in;
  28         char *msg_out;
  29         size_t buf_size;
  30         size_t msg_in_len_max;
  31         size_t msg_out_len_max;
  32         size_t msg_in_len;
  33         int fd_server;
  34         int fd_client_group;
  35         conn_msg_handle_t msg_handle;
  36 };
  37
  38 struct conn *
  39 conn_init(struct conn_params *p)
  40 {
  41         struct sockaddr_in server_address;
  42         struct conn *conn;
  43         int fd_server, fd_client_group, status;
  44
  45         memset(&server_address, 0, sizeof(server_address));
  46
  47         /* Check input arguments */
  48         if ((p == NULL) ||
  49                 (p->welcome == NULL) ||
  50                 (p->prompt == NULL) ||
  51                 (p->addr == NULL) ||
  52                 (p->buf_size == 0) ||
  53                 (p->msg_in_len_max == 0) ||
  54                 (p->msg_out_len_max == 0) ||
  55                 (p->msg_handle == NULL))
  56                 return NULL;
  57
  58         status = inet_aton(p->addr, &server_address.sin_addr);
  59         if (status == 0)
  60                 return NULL;
  61
  62         /* Memory allocation */
  63         conn = calloc(1, sizeof(struct conn));
  64         if (conn == NULL)
  65                 return NULL;
  66
  67         conn->welcome = calloc(1, CONN_WELCOME_LEN_MAX + 1);
  68         conn->prompt = calloc(1, CONN_PROMPT_LEN_MAX + 1);
  69         conn->buf = calloc(1, p->buf_size);
  70         conn->msg_in = calloc(1, p->msg_in_len_max + 1);
  71         conn->msg_out = calloc(1, p->msg_out_len_max + 1);
  72
  73         if ((conn->welcome == NULL) ||
  74                 (conn->prompt == NULL) ||
  75                 (conn->buf == NULL) ||
  76                 (conn->msg_in == NULL) ||
  77                 (conn->msg_out == NULL)) {
  78                 conn_free(conn);
  79                 return NULL;
  80         }
  81
  82         /* Server socket */
  83         server_address.sin_family = AF_INET;
  84         server_address.sin_port = htons(p->port);
  85
  86         fd_server = socket(AF_INET,
  87                 SOCK_STREAM | SOCK_NONBLOCK,
  88                 0);
  89         if (fd_server == -1) {
  90                 conn_free(conn);
  91                 return NULL;
  92         }
  93
  94         status = bind(fd_server,
  95                 (struct sockaddr *) &server_address,
  96                 sizeof(server_address));
  97         if (status == -1) {
  98                 conn_free(conn);
  99                 close(fd_server);
 100                 return NULL;
 101         }
 102
 103         status = listen(fd_server, 16);
 104         if (status == -1) {
 105                 conn_free(conn);
 106                 close(fd_server);
 107                 return NULL;
 108         }
 109
 110         /* Client group */
 111         fd_client_group = epoll_create(1);
 112         if (fd_client_group == -1) {
 113                 conn_free(conn);
 114                 close(fd_server);
 115                 return NULL;
 116         }
 117
 118         /* Fill in */
 119         strncpy(conn->welcome, p->welcome, CONN_WELCOME_LEN_MAX);
 120         strncpy(conn->prompt, p->prompt, CONN_PROMPT_LEN_MAX);
 121         conn->buf_size = p->buf_size;
 122         conn->msg_in_len_max = p->msg_in_len_max;
 123         conn->msg_out_len_max = p->msg_out_len_max;
 124         conn->msg_in_len = 0;
 125         conn->fd_server = fd_server;
 126         conn->fd_client_group = fd_client_group;
 127         conn->msg_handle = p->msg_handle;
 128
 129         return conn;
 130 }
 131
 132 void
 133 conn_free(struct conn *conn)
 134 {
 135         if (conn == NULL)
 136                 return;
 137
 138         if (conn->fd_client_group)
 139                 close(conn->fd_client_group);
 140
 141         if (conn->fd_server)
 142                 close(conn->fd_server);
 143
 144         free(conn->msg_out);
 145         free(conn->msg_in);
 146         free(conn->prompt);
 147         free(conn->welcome);
 148         free(conn);
 149 }
 150
 151 int
 152 conn_poll_for_conn(struct conn *conn)
 153 {
 154         struct sockaddr_in client_address;
 155         struct epoll_event event;
 156         socklen_t client_address_length;
 157         int fd_client, status;
 158
 159         /* Check input arguments */
 160         if (conn == NULL)
 161                 return -1;
 162
 163         /* Server socket */
 164         client_address_length = sizeof(client_address);
 165         fd_client = accept4(conn->fd_server,
 166                 (struct sockaddr *) &client_address,
 167                 &client_address_length,
 168                 SOCK_NONBLOCK);
 169         if (fd_client == -1) {
 170                 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
 171                         return 0;
 172
 173                 return -1;
 174         }
 175
 176         /* Client group */
 177         event.events = EPOLLIN | EPOLLRDHUP | EPOLLHUP;
 178         event.data.fd = fd_client;
 179
 180         status = epoll_ctl(conn->fd_client_group,
 181                 EPOLL_CTL_ADD,
 182                 fd_client,
 183                 &event);
 184         if (status == -1) {
 185                 close(fd_client);
 186                 return -1;
 187         }
 188
 189         /* Client */
 190         status = write(fd_client,
 191                 conn->welcome,
 192                 strlen(conn->welcome));
 193         if (status == -1) {
 194                 close(fd_client);
 195                 return -1;
 196         }
 197
 198         status = write(fd_client,
 199                 conn->prompt,
 200                 strlen(conn->prompt));
 201         if (status == -1) {
 202                 close(fd_client);
 203                 return -1;
 204         }
 205
 206         return 0;
 207 }
 208
 209 static int
 210 data_event_handle(struct conn *conn,
 211         int fd_client)
 212 {
 213         ssize_t len, i, status;
 214
 215         /* Read input message */
 216
 217         len = read(fd_client,
 218                 conn->buf,
 219                 conn->buf_size);
 220         if (len == -1) {
 221                 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
 222                         return 0;
 223
 224                 return -1;
 225         }
 226         if (len == 0)
 227                 return 0;
 228
 229         /* Handle input messages */
 230         for (i = 0; i < len; i++) {
 231                 if (conn->buf[i] == '\n') {
 232                         size_t n;
 233
 234                         conn->msg_in[conn->msg_in_len] = 0;
 235                         conn->msg_out[0] = 0;
 236
 237                         conn->msg_handle(conn->msg_in,
 238                                 conn->msg_out,
 239                                 conn->msg_out_len_max);
 240
 241                         n = strlen(conn->msg_out);
 242                         if (n) {
 243                                 status = write(fd_client,
 244                                         conn->msg_out,
 245                                         n);
 246                                 if (status == -1)
 247                                         return status;
 248                         }
 249
 250                         conn->msg_in_len = 0;
 251                 } else if (conn->msg_in_len < conn->msg_in_len_max) {
 252                         conn->msg_in[conn->msg_in_len] = conn->buf[i];
 253                         conn->msg_in_len++;
 254                 } else {
 255                         status = write(fd_client,
 256                                 MSG_CMD_TOO_LONG,
 257                                 strlen(MSG_CMD_TOO_LONG));
 258                         if (status == -1)
 259                                 return status;
 260
 261                         conn->msg_in_len = 0;
 262                 }
 263         }
 264
 265         /* Write prompt */
 266         status = write(fd_client,
 267                 conn->prompt,
 268                 strlen(conn->prompt));
 269         if (status == -1)
 270                 return status;
 271
 272         return 0;
 273 }
 274
 275 static int
 276 control_event_handle(struct conn *conn,
 277         int fd_client)
 278 {
 279         int status;
 280
 281         status = epoll_ctl(conn->fd_client_group,
 282                 EPOLL_CTL_DEL,
 283                 fd_client,
 284                 NULL);
 285         if (status == -1)
 286                 return -1;
 287
 288         status = close(fd_client);
 289         if (status == -1)
 290                 return -1;
 291
 292         return 0;
 293 }
 294
 295 int
 296 conn_poll_for_msg(struct conn *conn)
 297 {
 298         struct epoll_event event;
 299         int fd_client, status, status_data = 0, status_control = 0;
 300
 301         /* Check input arguments */
 302         if (conn == NULL)
 303                 return -1;
 304
 305         /* Client group */
 306         status = epoll_wait(conn->fd_client_group,
 307                 &event,
 308                 1,
 309                 0);
 310         if (status == -1)
 311                 return -1;
 312         if (status == 0)
 313                 return 0;
 314
 315         fd_client = event.data.fd;
 316
 317         /* Data available */
 318         if (event.events & EPOLLIN)
 319                 status_data = data_event_handle(conn, fd_client);
 320
 321         /* Control events */
 322         if (event.events & (EPOLLRDHUP | EPOLLERR | EPOLLHUP))
 323                 status_control = control_event_handle(conn, fd_client);
 324
 325         if (status_data || status_control)
 326                 return -1;
 327
 328         return 0;
 329 }