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Since:
1.0
Version:
1.0
Summary
Files
Data Structures
Macros
Defines the first address in h_addr_list for backward compatibility. |
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Functions
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Converts an integer from the host byte order to the network byte order. |
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htons (uint16_t n) |
Converts a 16-bit integer from the host byte order to the network byte order. |
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Converts an integer from the network byte order to the host byte order. |
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ntohs (uint16_t n) |
Converts a 16-bit integer from the network byte order to the host byte order. |
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Converts a string from the IPv4 numbers-and-dots notation to the binary data in network byte order. |
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inet_network (const char p) |
Converts a string from the IPv4 numbers-and-dots notation to the binary data in host byte order. |
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Converts a network address to a string in dotted-decimal format. |
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inet_pton (int af, const char restrict s, void *restrict a0) |
Converts a string to a network address in the specified address family. |
(int af, const void restrict a0, char restrict s, socklen_t l) |
Converts a network address in the specified address family to a string. |
inet_aton (const char s0, struct in_addr dest) |
Converts an IP address from the string format to the 32-bit binary format in network byte order. |
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Converts the network number and host address to the network address. |
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inet_lnaof (struct in_addr in) |
Converts an IP address into a host ID in host byte order without network bits. |
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Extracts the network number from the in_addr structure and converts it to the host byte order. |
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freeifaddrs (struct ifp) |
Frees the network interface information obtained by getifaddrs. |
if_freenameindex (struct idx) |
Frees the network adapter information obtained by if_nameindex. |
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Opens a connection to the database and sets the next entry to the first entry. |
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getprotoent (void) |
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getprotobynumber (int num) |
Retrieves the information about a protocol with the specified number. |
hstrerror (int ecode) |
Retrieves error information associated with the specified error number. |
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Converts binary data in network byte order into a standard 48-bit Ethernet host address in the colon hexadecimal notation. |
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ether_aton (const char x) |
Converts a standard 48-bit Ethernet host address in the colon hexadecimal notation into binary data in network byte order. |
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Converts binary data in network byte order into a standard 48-bit Ethernet host address in the colon hexadecimal notation. This function is reentrant. |
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ether_aton_r (const char x, struct ether_addr p_a) |
Converts a standard 48-bit Ethernet host address in the colon hexadecimal notation into binary data in network byte order. This function is reentrant. |
(const char src, unsigned char dst, int space, unsigned char dnptrs, unsigned char lastdnptr) |
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dn_expand (const unsigned char base, const unsigned char end, const unsigned char src, char dest, int space) |
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shutdown (int sockfd, int how) |
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(int sockfd, const struct sockaddr addr, socklen_t addrlen) |
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(int sockfd, const struct sockaddr addr, socklen_t addrlen) |
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accept (int sockfd, struct restrict addr, socklen_t *restrict addrlen) |
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getsockname (int fd, struct restrict addr, socklen_t restrict len) |
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getpeername (int fd, struct restrict addr, socklen_t restrict len) |
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send (int fd, const void buf, size_t len, int flags) |
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sendto (int fd, const void buf, size_t len, int flags, const struct addr, socklen_t alen) |
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recvfrom (int fd, void __restrict buf, size_t len, int flags, struct restrict addr, socklen_t *restrict alen) |
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sendmsg (int fd, const struct msghdr msg, int flags) |
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getsockopt (int fd, int level, int optname, void __restrict optval, socklen_t __restrict optlen) |
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(int fd, int level, int optname, const void *optval, socklen_t optlen) |
Details
Function Documentation
accept()
Description:
Accepts incoming connection requests.
Parameters:
| sockfd | Indicates the socket descriptor. |
| addr | Indicates the pointer to the socket address requiring for the connection. |
| addrlen | Indicates the length of the address structure pointed to by addr. |
Returns:
Returns a valid socket if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
The socket requiring for the connection is not of the NETCONN_TCP type. |
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bind()
Description:
Binds a local protocol address to a socket.
Parameters:
| sockfd | Indicates the socket descriptor. |
| addr | Indicates the address to be bound to the socket. |
| addrlen | Indicates the length of the address structure pointed to by addr. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
connect()
int connect (int sockfd, const struct [sockaddr]($api-api-SmartVision-Devices-sockaddr.md) * addr, socklen_t addrlen )
Description:
Initiates a connection to a socket.
Parameters:
| sockfd | Indicates the socket descriptor. |
| addr | Indicates the pointer to the address to be connected. |
| addrlen | Indicates the length of the address structure pointed to by addr. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
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dn_comp()
int dn_comp (const char * src, unsigned char * dst, int space, unsigned char ** dnptrs, unsigned char ** lastdnptr )
Description:
Compresses a network domain name.
To reduce the size of DNS messages, domain names in the messages are compressed. For details about the compression scheme, see RFC 1035.
Parameters:
Returns:
Returns the length of the compressed domain name if the operation is successful; returns -1 otherwise.
dn_expand()
int dn_expand (const unsigned char * base, const unsigned char * end, const unsigned char * src, char * dest, int space )
Description:
Expands a compressed domain name to a full domain name.
The compressed domain name is contained in a query or reply message.
Parameters:
Returns:
Returns the length of the compressed domain name if the operation is successful; returns -1 otherwise.
ether_aton()
struct ether_addr* ether_aton (const char * x)
Description:
Converts a standard 48-bit Ethernet host address in the colon hexadecimal notation into binary data in network byte order.
Parameters:
| x | Indicates the pointer to the host address to be converted. |
Returns:
Returns the binary data if the operation is successful; returns 0 otherwise.
ether_aton_r()
struct ether_addr* ether_aton_r (const char * x, struct ether_addr * p_a )
Description:
Converts a standard 48-bit Ethernet host address in the colon hexadecimal notation into binary data in network byte order. This function is reentrant.
This function is used in multitasking scenarios.
Parameters:
| x | Indicates the pointer to the host address to be converted. |
| p_a | Indicates the pointer to the temporary buffer during conversion. |
Returns:
Returns the binary data represented by ether_addr if the operation is successful; returns 0 otherwise.
ether_ntoa()
char* ether_ntoa (const struct ether_addr * p_a)
Description:
Converts binary data in network byte order into a standard 48-bit Ethernet host address in the colon hexadecimal notation.
Parameters:
| p_a | Indicates the pointer to the binary data to be converted. |
Attention:
Different from glibc (for example, 1:2:3:4:5:f), 0 is prefixed and letters are capitalized (for example, 01:02:03:04:05:0F).
Returns:
Returns the host address if the operation is successful; returns 0 otherwise.
ether_ntoa_r()
char* ether_ntoa_r (const struct ether_addr * p_a, char * x )
Description:
Converts binary data in network byte order into a standard 48-bit Ethernet host address in the colon hexadecimal notation. This function is reentrant.
This function is used in multitasking scenarios.
Parameters:
| p_a | Indicates the pointer to the binary data to be converted. |
| x | Indicates the pointer to the temporary buffer during conversion. |
Attention:
Different from glibc (for example, 1:2:3:4:5:f), 0 is prefixed and letters are capitalized (for example, 01:02:03:04:05:0F).
Returns:
Returns the host address if the operation is successful; returns 0 otherwise.
Description:
Frees the network interface information obtained by getifaddrs.
Parameters:
| ifp | Indicates the pointer to the network interface information to be freed. |
getpeername()
int getpeername (int fd, struct [sockaddr]($api-api-SmartVision-Devices-sockaddr.md) *restrict addr, socklen_t *restrict len )
Description:
Retrieves the peer address of the specified socket.
Parameters:
| fd | Indicates the socket descriptor. |
| addr | Indicates the pointer to the address to be retrieved. |
| len | Indicates the pointer to the length of the address pointed to by addr. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
getprotobyname()
struct protoent* getprotobyname (const char * name)
Description:
Retrieves the information about a specified protocol.
Parameters:
| addr | Indicates the pointer to the protocol name. |
Attention:
The /etc/protocols configuration file is not supported. Only the following built-in protocols are supported: ip/icmp/igmp/ggp/ipencap/st/tcp/egp/pup/udp/hmp/xns-idp/rdp/iso-tp4/xtp/ ddp/idpr-cmtp/ipv6/ipv6-route/ipv6-frag/idrp/rsvp/gre/esp/ah/skip/ipv6-icmp/ ipv6-nonxt/ipv6-opts/rspf/vmtp/ospf/ipip/encap/pim/raw (This protocol does not have the aliases attribute, that is, aliases is empty.)
Returns:
Returns the protocol information if the operation is successful; returns NULL otherwise.
getprotobynumber()
struct protoent* getprotobynumber (int num)
Description:
Retrieves the information about a protocol with the specified number.
Parameters:
| num | Indicates the protocol number. |
Attention:
The /etc/protocols configuration file is not supported. Only the following built-in protocols are supported: ip/icmp/igmp/ggp/ipencap/st/tcp/egp/pup/udp/hmp/xns-idp/rdp/iso-tp4/xtp/ ddp/idpr-cmtp/ipv6/ipv6-route/ipv6-frag/idrp/rsvp/gre/esp/ah/skip/ipv6-icmp/ ipv6-nonxt/ipv6-opts/rspf/vmtp/ospf/ipip/encap/pim/raw (This protocol does not have the aliases attribute, that is, aliases is empty.)
Returns:
Returns the protocol information if the operation is successful; returns NULL otherwise.
getprotoent()
struct protoent* getprotoent (void )
Description:
Retrieves the current protocol information.
Attention:
The /etc/protocols configuration file is not supported. Only the following built-in protocols are supported: ip/icmp/igmp/ggp/ipencap/st/tcp/egp/pup/udp/hmp/xns-idp/rdp/iso-tp4/xtp/ ddp/idpr-cmtp/ipv6/ipv6-route/ipv6-frag/idrp/rsvp/gre/esp/ah/skip/ipv6-icmp/ ipv6-nonxt/ipv6-opts/rspf/vmtp/ospf/ipip/encap/pim/raw (This protocol does not have the aliases attribute, that is, aliases is empty.)
Returns:
Returns the protocol information if the operation is successful; returns NULL otherwise.
getsockname()
Description:
Retrieves the local address of the specified socket.
Parameters:
| fd | Indicates the socket descriptor. |
| addr | Indicates the pointer to the address to be retrieved. |
| len | Indicates the pointer to the length of the address pointed to by addr. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
getsockopt()
Description:
Retrieves the socket options.
Parameters:
| fd | Indicates the socket descriptor. |
| level | Indicates the protocol level at which the option resides. Only SOL_SOCKET is supported. |
| optname | Indicates the socket options to be retrieved, which has the following values: |
| optval | Indicates the pointer to the option data. |
| optlen | Indicates the pointer to the size of the buffer pointed to by optval. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
herror()
void herror (const char * msg)
Description:
Prints error information.
Parameters:
| msg | Indicates the pointer to the string to be printed together with the error information. This parameter can be null. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
hstrerror()
const char* hstrerror (int ecode)
Description:
Retrieves error information associated with the specified error number.
Parameters:
| ecode | Indicates the error number. |
Returns:
Returns the string representing the error information.
htonl()
uint32_t htonl (uint32_t n)
Description:
Converts an integer from the host byte order to the network byte order.
Parameters:
| n | Indicates the integer in host byte order. |
Returns:
Returns the original data if the system is in big-endian mode; returns the converted data otherwise.
htons()
uint16_t htons (uint16_t n)
Description:
Converts a 16-bit integer from the host byte order to the network byte order.
Parameters:
| n | Indicates the integer in host byte order. |
Returns:
Returns the original data if the system is in big-endian mode; returns the converted data otherwise.
if_freenameindex()
void if_freenameindex (struct [if_nameindex]($api-api-SmartVision-Devices-if_nameindex.md) * idx)
Description:
Frees the network adapter information obtained by .
Parameters:
| idx | Indicates the pointer to the network adapter to be freed. |
inet_addr()
in_addr_t inet_addr (const char * p)
Description:
Converts a string from the IPv4 numbers-and-dots notation to the binary data in network byte order.
Parameters:
| p | Indicates the pointer to the string to be converted. |
Returns:
Returns the converted data if the operation is successful; returns -1 otherwise.
inet_aton()
int inet_aton (const char * s0, struct in_addr * dest )
Description:
Converts an IP address from the string format to the 32-bit binary format in network byte order.
Parameters:
| s0 | Indicates the pointer to the IP address to be converted. |
| dest | Indicates the pointer to the structure for conversion. |
Returns:
Returns 1 if the operation is successful; returns 0 otherwise.
inet_lnaof()
in_addr_t inet_lnaof (struct in_addr in)
Description:
Converts an IP address into a host ID in host byte order without network bits.
Parameters:
| in | Indicates the network address structure. |
Returns:
Returns the converted host address.
inet_makeaddr()
struct in_addr inet_makeaddr (in_addr_t n, in_addr_t h )
Description:
Converts the network number and host address to the network address.
Parameters:
| n | Indicates the network number. |
| h | Indicates the host address. |
Returns:
Returns the converted network address.
inet_netof()
in_addr_t inet_netof (struct in_addr in)
Description:
Extracts the network number from the in_addr structure and converts it to the host byte order.
Parameters:
| in | Indicates the network address structure. |
Returns:
Returns the converted network number.
in_addr_t inet_network (const char * p)
Description:
Converts a string from the IPv4 numbers-and-dots notation to the binary data in host byte order.
Parameters:
| p | Indicates the pointer to the string to be converted. |
Returns:
Returns the converted data if the operation is successful; returns -1 otherwise.
inet_ntoa()
char* inet_ntoa (struct in_addr in)
Description:
Converts a network address to a string in dotted-decimal format.
Parameters:
| in | Indicates the network address to be converted. |
Returns:
Returns the string.
inet_ntop()
Description:
Converts a network address in the specified address family to a string.
Parameters:
Returns:
Returns the converted string if the operation is successful; returns NULL and sets errno to a value in the following table if the operation fails.
inet_pton()
Description:
Converts a string to a network address in the specified address family.
Parameters:
| af | Indicates the address family. Currently, only AF_INET and AF_INET6 are supported. |
| s | Indicates the pointer to the string to be converted. |
| a0 | Indicates the pointer to the converted data. |
Returns:
Returns 1 if the operation is successful; returns 0 if the input address family is invalid; returns -1 if the operation fails. The error codes are set as follows:
listen()
int listen (int sockfd, int backlog )
Description:
Listens for network connections.
Parameters:
| sockfd | Indicates the socket descriptor. |
| backlog | Indicates the maximum length of the queue to accept incoming connection requests. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
ntohl()
uint32_t ntohl (uint32_t n)
Description:
Converts an integer from the network byte order to the host byte order.
Parameters:
| n | Indicates the integer in network byte order. |
Returns:
Returns the original data if the system is in big-endian mode; returns the converted data otherwise.
ntohs()
uint16_t ntohs (uint16_t n)
Description:
Converts a 16-bit integer from the network byte order to the host byte order.
Parameters:
| n | Indicates the integer in network byte order. |
Returns:
Returns the original data if the system is in big-endian mode; returns the converted data otherwise.
recv()
ssize_t recv (int fd, void * buf, size_t len, int flags )
Description:
Receives data from another socket.
Parameters:
Returns:
Returns the length of the received data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
recvfrom()
ssize_t recvfrom (int fd, void *__restrict buf, size_t len, int flags, struct [sockaddr]($api-api-SmartVision-Devices-sockaddr.md) *__restrict addr, socklen_t *__restrict alen )
Description:
Receives data from a specified socket.
Parameters:
Returns:
Returns the length of the received data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
recvmsg()
ssize_t recvmsg (int fd, struct msghdr * msg, int flags )
Description:
Receives data from a specified socket.
Parameters:
| fd | Indicates the socket descriptor. |
| msg | Indicates the pointer to the address to receive the message header. |
| flags | Indicates the socket flags. This parameter has the following values: |
Attention:
This function does not allow sending ancillary data. Currently, the length of the array defined by msg_iov can only be 1.
Returns:
Returns the length of the received data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
send()
ssize_t send (int fd, const void * buf, size_t len, int flags )
Description:
Sends data to another socket.
Parameters:
Returns:
Returns the length of the sent data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
sendmsg()
ssize_t sendmsg (int fd, const struct msghdr * msg, int flags )
Description:
Sends data to another socket.
Parameters:
| fd | Indicates the socket descriptor. |
| msg | Indicates the pointer to the address of the message header to be sent. |
| flags | Indicates the socket flags. This parameter has the following values: |
Attention:
This function does not support ancillary data.
Returns:
Returns the length of the sent data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
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sendto()
ssize_t sendto (int fd, const void * buf, size_t len, int flags, const struct [sockaddr]($api-api-SmartVision-Devices-sockaddr.md) * addr, socklen_t alen )
Description:
Sends data to another socket.
Parameters:
Returns:
Returns the length of the sent data if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
setprotoent()
void setprotoent (int stayopen)
Description:
Opens a connection to the database and sets the next entry to the first entry.
Parameters:
| stayopen | Reserved for interface compatibility (not used currently). |
Attention:
The stayopen parameter does not take effect. It is equivalent to nonzero for and zero for getprotobyname and getprotobynumbmer.
setsockopt()
int setsockopt (int fd, int level, int optname, const void * optval, socklen_t optlen )
Description:
Sets the socket options.
Parameters:
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
shutdown()
Description:
Shuts down a socket.
Parameters:
| sockfd | Indicates the socket descriptor. |
| how | Indicates how to shut down the socket. You can disable either receptions by SHUT_RD or transmissions by SHUT_WR, or both by SHUT_RDWR. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
Incorrect connection type obtained based on the socket descriptor |
socket()
Description:
Creates a socket and returns its descriptor.
Parameters:
| domain | Indicates the socket domain. |
| type | Indicates the socket type. |
| protocol | Indicates the socket protocol. |
Attention:
Only the following socket domains are supported: AF_INET, AF_INET6. Only the socket types SOCK_RAW, SOCK_DGRAM and SOCK_STREAM are supported, and the OR operation between the extra socket flag and the socket type is not supported.
Returns:
Returns the descriptor for the new socket if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
