привязать сокет к привилегированному IP-порту (bind a socket to a privileged IP port)
Имя (Name)
bindresvport - bind a socket to a privileged IP port
Синопсис (Synopsis)
#include <sys/types.h>
#include <netinet/in.h>
int bindresvport(int sockfd, struct sockaddr_in *sin);
Описание (Description)
bindresvport() is used to bind the socket referred to by the file
descriptor sockfd to a privileged anonymous IP port, that is, a
port number arbitrarily selected from the range 512 to 1023.
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).)
Возвращаемое значение (Return value)
bindresvport() returns 0 on success; otherwise -1 is returned and
errno is set to indicate the error.
Ошибки (Error)
bindresvport() can fail for any of the same reasons as bind(2).
In addition, the following errors may occur:
EACCES 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).
EADDRINUSE
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.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌───────────────┬───────────────┬────────────────────────────────┐
│Interface │ Attribute │ Value │
├───────────────┼───────────────┼────────────────────────────────┤
│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.
Стандарты (Conforming to)
Not in POSIX.1. Present on the BSDs, Solaris, and many other
systems.
Примечание (Note)
Unlike some bindresvport() implementations, the glibc
implementation ignores any value that the caller supplies in
sin->sin_port.
Смотри также (See also)
bind(2), getsockname(2)
