+/*
+ * Is pppd using pty as a device (opposed to notty or pty opt).
+ */
+bool ppp_using_pty();
+
+/*
+ * Device is synchronous serial device
+ */
+bool ppp_sync_serial();
+
+/*
+ * Modem mode
+ */
+bool ppp_get_modem();
+
+/*
+ * Control the mode of the tty terminal
+ */
+void ppp_set_modem(bool on);
+
+/*
+ * Set the current session number, e.g. for PPPoE
+ */
+void ppp_set_session_number(int number);
+
+/*
+ * Set the current session number, e.g. for PPPoE
+ */
+int ppp_get_session_number(void);
+
+/*
+ * Check if pppd got signaled, returns 0 if not signaled, returns -1 on failure, and the signal number when signaled.
+ */
+bool ppp_signaled(int sig);
+
+/*
+ * Maximum connect time in seconds
+ */
+int ppp_get_max_connect_time(void);
+
+/*
+ * Set the maximum connect time in seconds
+ */
+void ppp_set_max_connect_time(unsigned int max);
+
+/*
+ * Get the link idle time before shutting the link down
+ */
+int ppp_get_max_idle_time(void);
+
+/*
+ * Set the link idle time before shutting the link down
+ */
+void ppp_set_max_idle_time(unsigned int idle);
+
+/*
+ * Get the duration the link was up (uptime)
+ */
+int ppp_get_link_uptime();
+
+/*
+ * Get the ipparam configured with pppd
+ */
+const char *ppp_ipparam();
+
+/*
+ * check if IP address is unreasonable
+ */
+bool ppp_bad_ip_addr(uint32_t);
+
+/*
+ * Expose an environment variable to scripts
+ */
+void ppp_script_setenv(char *, char *, int);
+
+/*
+ * Unexpose an environment variable to scripts
+ */
+void ppp_script_unsetenv(char *);
+
+/*
+ * Test whether ppp kernel support exists
+ */
+int ppp_check_kernel_support(void);
+
+/*
+ * Restore device setting
+ */
+void ppp_generic_disestablish(int dev_fd);
+
+/*
+ * Set the interface MTU
+ */
+void ppp_set_mtu(int, int);
+
+/*
+ * Get the interface MTU
+ */
+int ppp_get_mtu(int);
+
+/*
+ * Make a ppp interface
+ */
+int ppp_generic_establish(int dev_fd);
+
+/*
+ * Get the peer's authentication name
+ */
+const char *ppp_peer_authname(char *buf, size_t bufsz);
+
+/*
+ * Get the remote name
+ */
+const char *ppp_remote_name();
+
+/*
+ * Get the remote number (if set), otherwise return NULL
+ */
+const char *ppp_get_remote_number(void);
+
+/*
+ * Set the remote number, typically it's a MAC address
+ */
+void ppp_set_remote_number(const char *buf);
+
+/*
+ * Get the current interface unit for the pppX device
+ */
+int ppp_ifunit();
+
+/*
+ * Get the current interface name
+ */
+const char *ppp_ifname();
+
+/*
+ * Get the current interface name
+ */
+int ppp_get_ifname(char *buf, size_t bufsz);
+
+/*
+ * Set the current interface name, ifname is a \0 terminated string
+ */
+void ppp_set_ifname(const char *ifname);
+
+/*
+ * Set the original devnam (prior to any renaming, etc).
+ */
+int ppp_set_pppdevnam(const char *name);
+
+/*
+ * Get the original devnam (prior to any renaming, etc).
+ */
+const char *ppp_pppdevnam();
+
+/*
+ * Get the current devnam, e.g. /dev/ttyS0, /dev/ptmx
+ */
+const char *ppp_devnam();
+
+/*
+ * Set the device name
+ */
+int ppp_set_devnam(const char *name);
+
+/*
+ * Definition for the notify callback function
+ * ctx - contextual argument provided with the registration
+ * arg - anything passed by the notification, e.g. phase, pid, etc
+ */
+typedef void (ppp_notify_fn)(void *ctx, int arg);
+
+/*
+ * Add a callback notification for when a given event has occured
+ */
+void ppp_add_notify(ppp_notify_t type, ppp_notify_fn *func, void *ctx);
+
+/*
+ * Remove a callback notification previously registered
+ */
+void ppp_del_notify(ppp_notify_t type, ppp_notify_fn *func, void *ctx);
+
+/*
+ * Get the path prefix in which a file is installed
+ */
+int ppp_get_path(ppp_path_t type, char *buf, size_t bufsz);
+
+/*
+ * Get the file with path prefix
+ */
+int ppp_get_filepath(ppp_path_t type, const char *name, char *buf, size_t bufsz);
+
+/*
+ * Check if pppd is to re-open link after it goes down
+ */
+bool ppp_persist();
+
+/*
+ * Hooks to enable plugins to hook into various parts of the code
+ */
+
+struct ppp_idle; /* Declared in <linux/ppp_defs.h> */
+extern int (*idle_time_hook)(struct ppp_idle *);
+extern int (*new_phase_hook)(int);
+extern int (*holdoff_hook)(void);
+extern int (*allowed_address_hook)(uint32_t addr);
+extern void (*snoop_recv_hook)(unsigned char *p, int len);
+extern void (*snoop_send_hook)(unsigned char *p, int len);
+
+#ifdef __cplusplus
+}