Functions to filter access to the FTP server and to work with user accounts. More...
Functions | |
bool | netFTPs_AcceptClient (const NET_ADDR *addr) |
Accept or deny connection from remote FTP client. [user-provided]. | |
uint8_t | netFTPs_CheckUsername (const char *username) |
Check if an user account exists in the user database. [user-provided]. | |
bool | netFTPs_CheckPassword (uint8_t user_id, const char *password) |
Check user account password in the user database. [user-provided]. | |
bool | netFTPs_FileAccess (uint8_t user_id, const char *fname, uint32_t access) |
Check if remote user is allowed to access a file on FTP server. [user-provided]. | |
uint8_t | netFTPs_GetUserId (void) |
Retrieve the user identification number. [thread-safe]. | |
Functions to filter access to the FTP server and to work with user accounts.
To filter the access to the FTP server based on the IP address and port of the connecting client, the optional function netFTPs_AcceptClient is used. It is part of the template file FTP_Server_Access.c. If this template file is missing in the project, the function will not be available and thus connections from all remote clients will be accepted. You need to adapt the function to the application's needs by specifying the rules for allowed/blocked clients. The FTP server will use the information in this function to filter the access.
The multi-user login allows you to create different profiles for different users or groups of users. The profiles define the access rights to different files on the FTP server. The users which are allowed to access the FTP server are stored in an user database.
If you want to use multi-user authentication, you need to check the Enable User Authentication in the configuration file (Net_Config_FTP_Server.h). The default account is a system administrator account, which has no restrictions. All other accounts are created in a separate FTP_Server_Multiuser.c module. To enable a list of users, you need to adapt the following functions that are included in this module:
The following function is included in the Network Component library rl_net.h:
bool netFTPs_AcceptClient | ( | const NET_ADDR * | addr | ) |
Accept or deny connection from remote FTP client. [user-provided].
[in] | addr | structure containing IP address and port of remote FTP client. |
The function netFTPs_AcceptClient checks if a connection from the remote client is allowed or not. This enables remote client filtering. You can selectively decide which clients are allowed to connect to the FTP server and which are not.
The argument addr points to a buffer containing IP address and port of the remote machine.
Code Example
The following example is available in the user code template file FTP_Server_Access.c. Customize it to the application's needs.
bool netFTPs_CheckPassword | ( | uint8_t | user_id, |
const char * | password | ||
) |
Check user account password in the user database. [user-provided].
[in] | user_id | user identification number. |
[in] | password | pointer to password. |
The function netFTPs_CheckPassword authenticates the password for a specified user ID.
The argument user_id is the identification number of a user.
The argument password points to the password that gets checked.
Code Example
The following example is available in the user code template file FTP_Server_Multiuser.c. Customize it to the application's needs.
uint8_t netFTPs_CheckUsername | ( | const char * | username | ) |
Check if an user account exists in the user database. [user-provided].
[in] | username | pointer to username. |
The function netFTPs_CheckUsername authenticates the username and returns the corresponding identification number. A value of 0 is returned if the user does not exist.
The argument username points to the user name.
Code Example
The following example is available in the user code template file FTP_Server_Multiuser.c. Customize it to the application's needs.
bool netFTPs_FileAccess | ( | uint8_t | user_id, |
const char * | fname, | ||
uint32_t | access | ||
) |
Check if remote user is allowed to access a file on FTP server. [user-provided].
[in] | user_id | user identification number. |
[in] | fname | full path of a file to access. |
[in] | access | access mode as defined with Network Access definitions. |
The function netFTPs_FileAccess checks if file access is allowed for a specific user. This allows access protection of sensitive files. The access to protected files will be blocked for unprivileged users. The error code "550 Access is denied" will be returned to the client if access is not allowed.
The argument user_id is the user identification number as returned by netFTPs_CheckUsername. user_id identifies the user who is trying to access the specified file.
The argument fname points to a buffer containing the file name with path which should be accessed. The file name is a null-terminated string.
The argument access specifies the requested type of file access:
Code Example
The following example is available in the user code template file FTP_Server_Multiuser.c. Customize it to the application's needs.
uint8_t netFTPs_GetUserId | ( | void | ) |
Retrieve the user identification number. [thread-safe].
The function netFTPs_GetUserId retrieves the user identification number.
Code Example