|BINDRESVPORT(3)||Linux Programmer's Manual||BINDRESVPORT(3)|
#include <sys/types.h> #include <netinet/in.h>
int bindresvport(int sockfd, struct sockaddr_in *sin);
If the bind(2) performed by bindresvport() is successful, and sin is not NULL, then sin->sin_port returns the port number actually allocated.
sin can be NULL, in which case sin->sin_family is implicitly taken to be AF_INET. However, in this case, bindresvport() has no way to return the port number actually allocated. (This information can later be obtained using getsockname(2).)
- The calling process was not privileged (on Linux: the calling process did not have the CAP_NET_BIND_SERVICE capability in the user namespace governing its network namespace).
- All privileged ports are in use.
- EAFNOSUPPORT (EPFNOSUPPORT in glibc 2.7 and earlier)
- sin is not NULL and sin->sin_family is not AF_INET.
|bindresvport ()||Thread safety||glibc >= 2.17: MT-Safe . glibc < 2.17: MT-Unsafe|
The bindresvport() function uses a static variable that was not protected by a lock before glibc 2.17, rendering the function MT-Unsafe.