| /* |
| * inet/bindresvport.c |
| */ |
| |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #define START_PORT 768 |
| #define END_PORT IPPORT_RESERVED |
| #define NUM_PORTS (END_PORT - START_PORT) |
| |
| int bindresvport(int sd, struct sockaddr_in *sin) |
| { |
| struct sockaddr_in me; |
| static short port; |
| int ret = 0; |
| int i; |
| |
| if (sin == NULL) { |
| memset(&me, 0, sizeof(me)); |
| sin = &me; |
| sin->sin_family = AF_INET; |
| } else if (sin->sin_family != AF_INET) { |
| errno = EPFNOSUPPORT; |
| return -1; |
| } |
| |
| if (port == 0) |
| port = START_PORT + (getpid() % NUM_PORTS); |
| |
| for (i = 0; i < NUM_PORTS; i++, port++) { |
| if (port == END_PORT) |
| port = START_PORT; |
| sin->sin_port = htons(port); |
| |
| ret = bind(sd, (struct sockaddr *)sin, sizeof(*sin)); |
| if (ret != -1) |
| break; |
| } |
| |
| return ret; |
| } |