wt/mongoose
1
0 Fork 0
mirror of https://github.com/cesanta/mongoose.git synced 2026-10-23 11:44:53 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add L2 PPP and PPPoE

Browse Source
This commit is contained in:
Sergio R. Caprile committed 2026-04-01 14:39:28 -03:00
1 parent ae5a2263ac
commit 70650fedcf
23 files changed
+2019 -909
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

src/drivers/at_cmd.c
+153
View File
@@ -0,0 +1,153 @@
#include "net_builtin.h"
#if MG_ENABLE_TCPIP && defined(MG_ENABLE_DRIVER_ATCMD) && MG_ENABLE_DRIVER_ATCMD
#define MG_HDLC_FLAG 0x7e // HDLC frame delimiter
#define MG_HDLC_ESC 0x7d // HDLC escape byte for byte stuffing
#define MG_ATCMD_AT_TIMEOUT 2000
static size_t print_atcmd(void (*out)(char, void *), void *arg, va_list *ap) {
struct mg_str s = va_arg(*ap, struct mg_str);
for (size_t i = 0; i < s.len; i++) out(s.buf[i] < 0x20 ? '.' : s.buf[i], arg);
return s.len;
}
static void mg_atcmd_reset(struct mg_tcpip_driver_atcmd_data *dd) {
dd->script_index = 0;
dd->deadline = 0;
if (dd->reset) dd->reset(dd->usart);
}
static bool mg_atcmd_handle(struct mg_tcpip_if *ifp) {
struct mg_tcpip_driver_atcmd_data *dd = (struct mg_tcpip_driver_atcmd_data *) ifp->driver_data;
if (dd->script == NULL || dd->script_index < 0) return true;
if (dd->deadline == 0) dd->deadline = mg_millis() + MG_ATCMD_AT_TIMEOUT;
for (;;) {
if (dd->script_index % 2 == 0) { // send AT command
const char *cmd = dd->script[dd->script_index];
MG_DEBUG(("send AT[%d]: %M", dd->script_index, print_atcmd, mg_str(cmd)));
while (*cmd) dd->tx(dd->usart, *cmd++);
dd->script_index++;
ifp->recv_queue.head = 0;
} else { // check AT command response
const char *expect = dd->script[dd->script_index];
struct mg_queue *q = &ifp->recv_queue;
for (;;) {
int c;
bool is_timeout = dd->deadline > 0 && mg_millis() > dd->deadline;
bool is_overflow = q->head >= q->size - 1;
if (is_timeout || is_overflow) {
MG_ERROR(("AT error: %s, retrying...", is_timeout ? "timeout" : "overflow"));
mg_atcmd_reset(dd);
return false; // FAIL
}
if ((c = dd->rx(dd->usart)) < 0) return false; // no data
q->buf[q->head++] = c;
if (mg_match(mg_str_n(q->buf, q->head), mg_str(expect), NULL)) {
MG_DEBUG(("recv AT[%d]: %M", dd->script_index, print_atcmd,
mg_str_n(q->buf, q->head)));
dd->script_index++;
q->head = 0;
break;
}
}
}
if (dd->script[dd->script_index] == NULL) {
MG_DEBUG(("finished AT script"));
dd->script_index = -1;
return true;
}
}
}
static void byte_stuff(struct mg_tcpip_driver_atcmd_data *dd, uint8_t b);
static bool byte_unstuff(struct mg_tcpip_driver_atcmd_data *dd, uint8_t *p);
static size_t mg_atcmd_rx(void *buf, size_t len, struct mg_tcpip_if *ifp) {
struct mg_tcpip_driver_atcmd_data *dd = (struct mg_tcpip_driver_atcmd_data *) ifp->driver_data;
struct mg_queue *q = &ifp->recv_queue;
if (!dd->link) return 0;
while (q->head < q->size) { // read as many bytes as possible
uint8_t b;
int c = dd->rx(dd->usart);
if (c < 0) return 0; // no more bytes, exit
b = (uint8_t) c;
if (b == MG_HDLC_FLAG) {
if (q->head == 0) { // first flag: skip
dd->unstuffing = false;
continue;
} else { // last flag: end of frame, exit loop
break;
}
}
if (!dd->no_byte_stuff && !byte_unstuff(dd, &b)) continue;
q->buf[q->head++] = b;
}
len = (q->head <= len) ? q->head : 0;
memmove(buf, q->buf, len);
q->head = 0;
return len;
}
static size_t mg_atcmd_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) {
struct mg_tcpip_driver_atcmd_data *dd = (struct mg_tcpip_driver_atcmd_data *) ifp->driver_data;
uint8_t *p = (uint8_t *) buf;
size_t n = len;
if (!dd->link) return 0;
dd->tx(dd->usart, MG_HDLC_FLAG);
while (n--) {
if (dd->no_byte_stuff) {
dd->tx(dd->usart, *p++);
} else {
byte_stuff(dd, *p++);
}
}
dd->tx(dd->usart, MG_HDLC_FLAG);
return len;
}
static bool mg_atcmd_init(struct mg_tcpip_if *ifp) {
ifp->recv_queue.size = 1506; // PPP MTU=1500 + header + HDLC w/ no flags
return true;
}
static bool mg_atcmd_poll(struct mg_tcpip_if *ifp, bool s1) {
struct mg_tcpip_driver_atcmd_data *dd = (struct mg_tcpip_driver_atcmd_data *) ifp->driver_data;
dd->link = mg_atcmd_handle(ifp);
return s1 ? dd->link :false;
}
struct mg_tcpip_driver mg_tcpip_driver_atcmd = {mg_atcmd_init, mg_atcmd_tx, mg_atcmd_rx, mg_atcmd_poll};
static void byte_stuff(struct mg_tcpip_driver_atcmd_data *dd, uint8_t b) {
if ((b < 0x20) || (b == MG_HDLC_ESC) || (b == MG_HDLC_FLAG)) {
dd->tx(dd->usart, MG_HDLC_ESC);
dd->tx(dd->usart, b ^ 0x20);
} else {
dd->tx(dd->usart, b);
}
}
static bool byte_unstuff(struct mg_tcpip_driver_atcmd_data *dd, uint8_t *p) {
if (!dd->unstuffing) {
if (*p == MG_HDLC_ESC) {
dd->unstuffing = true;
return false;
} else {
return true;
}
}
dd->unstuffing = false;
*p ^= 0x20;
return true;
}
#endif
src/drivers/at_cmd.h
+14
View File
@@ -0,0 +1,14 @@
#pragma once
struct mg_tcpip_driver_atcmd_data {
void *usart; // Opaque UART/SPI descriptor
void (*reset)(void *); // Modem hardware reset
void (*tx)(void *, uint8_t); // USART transmit single byte
int (*rx)(void *); // USART receive single byte
const char **script; // List of AT commands and expected replies
int script_index; // Index of the current AT command in the list
uint64_t deadline; // AT command deadline in ms
bool no_byte_stuff; // Do not perform byte stuffing/unstuffing
bool link; // internal use: done with AT processing
bool unstuffing; // internal use: unstuffing state
};
src/drivers/ppp.c
-328
View File
@@ -1,328 +0,0 @@
#include "net_builtin.h"
#if MG_ENABLE_TCPIP && defined(MG_ENABLE_DRIVER_PPP) && MG_ENABLE_DRIVER_PPP
#define MG_PPP_FLAG 0x7e // PPP frame delimiter
#define MG_PPP_ESC 0x7d // PPP escape byte for special characters
#define MG_PPP_ADDR 0xff
#define MG_PPP_CTRL 0x03
#define MG_PPP_PROTO_IP 0x0021
#define MG_PPP_PROTO_LCP 0xc021
#define MG_PPP_PROTO_IPCP 0x8021
#define MG_PPP_IPCP_REQ 1
#define MG_PPP_IPCP_ACK 2
#define MG_PPP_IPCP_NACK 3
#define MG_PPP_IPCP_IPADDR 3
#define MG_PPP_LCP_CFG_REQ 1
#define MG_PPP_LCP_CFG_ACK 2
#define MG_PPP_LCP_CFG_NACK 3
#define MG_PPP_LCP_CFG_REJECT 4
#define MG_PPP_LCP_CFG_TERM_REQ 5
#define MG_PPP_LCP_CFG_TERM_ACK 6
#define MG_PPP_AT_TIMEOUT 2000
static size_t print_atcmd(void (*out)(char, void *), void *arg, va_list *ap) {
struct mg_str s = va_arg(*ap, struct mg_str);
for (size_t i = 0; i < s.len; i++) out(s.buf[i] < 0x20 ? '.' : s.buf[i], arg);
return s.len;
}
static void mg_ppp_reset(struct mg_tcpip_driver_ppp_data *dd) {
dd->script_index = 0;
dd->deadline = 0;
if (dd->reset) dd->reset(dd->uart);
}
static bool mg_ppp_atcmd_handle(struct mg_tcpip_if *ifp) {
struct mg_tcpip_driver_ppp_data *dd =
(struct mg_tcpip_driver_ppp_data *) ifp->driver_data;
if (dd->script == NULL || dd->script_index < 0) return true;
if (dd->deadline == 0) dd->deadline = mg_millis() + MG_PPP_AT_TIMEOUT;
for (;;) {
if (dd->script_index % 2 == 0) { // send AT command
const char *cmd = dd->script[dd->script_index];
MG_DEBUG(("send AT[%d]: %M", dd->script_index, print_atcmd, mg_str(cmd)));
while (*cmd) dd->tx(dd->uart, *cmd++);
dd->script_index++;
ifp->recv_queue.head = 0;
} else { // check AT command response
const char *expect = dd->script[dd->script_index];
struct mg_queue *q = &ifp->recv_queue;
for (;;) {
int c;
int is_timeout = dd->deadline > 0 && mg_millis() > dd->deadline;
int is_overflow = q->head >= q->size - 1;
if (is_timeout || is_overflow) {
MG_ERROR(("AT error: %s, retrying...",
is_timeout ? "timeout" : "overflow"));
mg_ppp_reset(dd);
return false; // FAIL: timeout
}
if ((c = dd->rx(dd->uart)) < 0) return false; // no data
q->buf[q->head++] = c;
if (mg_match(mg_str_n(q->buf, q->head), mg_str(expect), NULL)) {
MG_DEBUG(("recv AT[%d]: %M", dd->script_index, print_atcmd,
mg_str_n(q->buf, q->head)));
dd->script_index++;
q->head = 0;
break;
}
}
}
if (dd->script[dd->script_index] == NULL) {
MG_DEBUG(("finished AT script"));
dd->script_index = -1;
return true;
}
}
}
static bool mg_ppp_init(struct mg_tcpip_if *ifp) {
ifp->recv_queue.size = 3000; // MTU=1500, worst case escaping = 2x
return true;
}
// Calculate FCS/CRC for PPP frames. Could be implemented faster using lookup
// tables.
static uint32_t fcs_do(uint32_t fcs, uint8_t x) {
for (int i = 0; i < 8; i++) {
fcs = ((fcs ^ x) & 1) ? (fcs >> 1) ^ 0x8408 : fcs >> 1;
x >>= 1;
}
return fcs;
}
static bool mg_ppp_poll(struct mg_tcpip_if *ifp, bool s1) {
(void) s1;
return ifp->driver_data != NULL;
}
// Transmit a single byte as part of the PPP frame (escaped, if needed)
static void mg_ppp_tx_byte(struct mg_tcpip_driver_ppp_data *dd, uint8_t b) {
if ((b < 0x20) || (b == MG_PPP_ESC) || (b == MG_PPP_FLAG)) {
dd->tx(dd->uart, MG_PPP_ESC);
dd->tx(dd->uart, b ^ 0x20);
} else {
dd->tx(dd->uart, b);
}
}
// Transmit a single PPP frame for the given protocol
static void mg_ppp_tx_frame(struct mg_tcpip_driver_ppp_data *dd, uint16_t proto,
uint8_t *data, size_t datasz) {
uint16_t crc;
uint32_t fcs = 0xffff;
dd->tx(dd->uart, MG_PPP_FLAG);
mg_ppp_tx_byte(dd, MG_PPP_ADDR);
mg_ppp_tx_byte(dd, MG_PPP_CTRL);
mg_ppp_tx_byte(dd, proto >> 8);
mg_ppp_tx_byte(dd, proto & 0xff);
fcs = fcs_do(fcs, MG_PPP_ADDR);
fcs = fcs_do(fcs, MG_PPP_CTRL);
fcs = fcs_do(fcs, proto >> 8);
fcs = fcs_do(fcs, proto & 0xff);
for (unsigned int i = 0; i < datasz; i++) {
mg_ppp_tx_byte(dd, data[i]);
fcs = fcs_do(fcs, data[i]);
}
crc = fcs & 0xffff;
mg_ppp_tx_byte(dd, ~crc); // send CRC, note the byte order
mg_ppp_tx_byte(dd, ~crc >> 8);
dd->tx(dd->uart, MG_PPP_FLAG); // end of frame
}
// Send Ethernet frame as PPP frame
static size_t mg_ppp_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) {
struct mg_tcpip_driver_ppp_data *dd =
(struct mg_tcpip_driver_ppp_data *) ifp->driver_data;
if (ifp->state != MG_TCPIP_STATE_READY) return 0;
// XXX: what if not an IP protocol?
mg_ppp_tx_frame(dd, MG_PPP_PROTO_IP, (uint8_t *) buf + 14, len - 14);
return len;
}
// Given a full PPP frame, unescape it in place and verify FCS, returns actual
// data size on success or 0 on error.
static size_t mg_ppp_verify_frame(uint8_t *buf, size_t bufsz) {
int unpack = 0;
uint16_t crc;
size_t pktsz = 0;
uint32_t fcs = 0xffff;
for (unsigned int i = 0; i < bufsz; i++) {
if (unpack == 0) {
if (buf[i] == 0x7d) {
unpack = 1;
} else {
buf[pktsz] = buf[i];
fcs = fcs_do(fcs, buf[pktsz]);
pktsz++;
}
} else {
unpack = 0;
buf[pktsz] = buf[i] ^ 0x20;
fcs = fcs_do(fcs, buf[pktsz]);
pktsz++;
}
}
crc = fcs & 0xffff;
if (crc != 0xf0b8) {
MG_DEBUG(("bad crc: %04x", crc));
return 0;
}
if (pktsz < 6 || buf[0] != MG_PPP_ADDR || buf[1] != MG_PPP_CTRL) {
return 0;
}
return pktsz - 2; // strip FCS
}
// fetch as much data as we can, until a single PPP frame is received
static size_t mg_ppp_rx_frame(struct mg_tcpip_driver_ppp_data *dd,
struct mg_queue *q) {
while (q->head < q->size) {
int c;
if ((c = dd->rx(dd->uart)) < 0) {
return 0;
}
if (c == MG_PPP_FLAG) {
if (q->head > 0) {
break;
} else {
continue;
}
}
q->buf[q->head++] = c;
}
size_t n = mg_ppp_verify_frame((uint8_t *) q->buf, q->head);
if (n == 0) {
MG_DEBUG(("invalid PPP frame of %d bytes", q->head));
q->head = 0;
return 0;
}
q->head = n;
return q->head;
}
static void mg_ppp_handle_lcp(struct mg_tcpip_if *ifp, uint8_t *lcp,
size_t lcpsz) {
uint8_t id;
uint16_t len;
struct mg_tcpip_driver_ppp_data *dd =
(struct mg_tcpip_driver_ppp_data *) ifp->driver_data;
if (lcpsz < 4) return;
id = lcp[1];
len = (((uint16_t) lcp[2]) << 8) | (lcp[3]);
switch (lcp[0]) {
case MG_PPP_LCP_CFG_REQ: {
if (len == 4) {
MG_DEBUG(("LCP config request of %d bytes, acknowledging...", len));
lcp[0] = MG_PPP_LCP_CFG_ACK;
mg_ppp_tx_frame(dd, MG_PPP_PROTO_LCP, lcp, len);
lcp[0] = MG_PPP_LCP_CFG_REQ;
mg_ppp_tx_frame(dd, MG_PPP_PROTO_LCP, lcp, len);
} else {
MG_DEBUG(("LCP config request of %d bytes, rejecting...", len));
lcp[0] = MG_PPP_LCP_CFG_REJECT;
mg_ppp_tx_frame(dd, MG_PPP_PROTO_LCP, lcp, len);
}
} break;
case MG_PPP_LCP_CFG_TERM_REQ: {
uint8_t ack[4] = {MG_PPP_LCP_CFG_TERM_ACK, id, 0, 4};
MG_DEBUG(("LCP termination request, acknowledging..."));
mg_ppp_tx_frame(dd, MG_PPP_PROTO_LCP, ack, sizeof(ack));
mg_ppp_reset(dd);
ifp->state = MG_TCPIP_STATE_UP;
if (dd->reset) dd->reset(dd->uart);
} break;
}
}
static void mg_ppp_handle_ipcp(struct mg_tcpip_if *ifp, uint8_t *ipcp,
size_t ipcpsz) {
struct mg_tcpip_driver_ppp_data *dd =
(struct mg_tcpip_driver_ppp_data *) ifp->driver_data;
uint16_t len;
uint8_t id;
uint8_t req[] = {
MG_PPP_IPCP_REQ, 0, 0, 10, MG_PPP_IPCP_IPADDR, 6, 0, 0, 0, 0};
if (ipcpsz < 4) return;
id = ipcp[1];
len = (((uint16_t) ipcp[2]) << 8) | (ipcp[3]);
switch (ipcp[0]) {
case MG_PPP_IPCP_REQ:
MG_DEBUG(("got IPCP config request, acknowledging..."));
if (len >= 10 && ipcp[4] == MG_PPP_IPCP_IPADDR) {
uint8_t *ip = ipcp + 6;
MG_DEBUG(("host ip: %d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]));
}
ipcp[0] = MG_PPP_IPCP_ACK;
mg_ppp_tx_frame(dd, MG_PPP_PROTO_IPCP, ipcp, len);
req[1] = id;
// Request IP address 0.0.0.0
mg_ppp_tx_frame(dd, MG_PPP_PROTO_IPCP, req, sizeof(req));
break;
case MG_PPP_IPCP_ACK:
// This usually does not happen, as our "preferred" IP address is invalid
MG_DEBUG(("got IPCP config ack, link is online now"));
ifp->state = MG_TCPIP_STATE_READY;
break;
case MG_PPP_IPCP_NACK:
MG_DEBUG(("got IPCP config nack"));
// NACK contains our "suggested" IP address, use it
if (len >= 10 && ipcp[4] == MG_PPP_IPCP_IPADDR) {
uint8_t *ip = ipcp + 6;
MG_DEBUG(("ipcp ack, ip: %d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]));
ipcp[0] = MG_PPP_IPCP_REQ;
mg_ppp_tx_frame(dd, MG_PPP_PROTO_IPCP, ipcp, len);
ifp->ip = ifp->mask = MG_IPV4(ip[0], ip[1], ip[2], ip[3]);
ifp->state = MG_TCPIP_STATE_READY;
}
break;
}
}
static size_t mg_ppp_rx(void *ethbuf, size_t ethlen, struct mg_tcpip_if *ifp) {
uint8_t *eth = ethbuf;
size_t ethsz = 0;
struct mg_tcpip_driver_ppp_data *dd =
(struct mg_tcpip_driver_ppp_data *) ifp->driver_data;
uint8_t *buf = (uint8_t *) ifp->recv_queue.buf;
if (!mg_ppp_atcmd_handle(ifp)) return 0;
size_t bufsz = mg_ppp_rx_frame(dd, &ifp->recv_queue);
if (!bufsz) return 0;
uint16_t proto = (((uint16_t) buf[2]) << 8) | (uint16_t) buf[3];
switch (proto) {
case MG_PPP_PROTO_LCP: mg_ppp_handle_lcp(ifp, buf + 4, bufsz - 4); break;
case MG_PPP_PROTO_IPCP: mg_ppp_handle_ipcp(ifp, buf + 4, bufsz - 4); break;
case MG_PPP_PROTO_IP:
MG_VERBOSE(("got IP packet of %d bytes", bufsz - 4));
memmove(eth + 14, buf + 4, bufsz - 4);
memmove(eth, ifp->mac, 6);
memmove(eth + 6, "\xff\xff\xff\xff\xff\xff", 6);
eth[12] = 0x08;
eth[13] = 0x00;
ethsz = bufsz - 4 + 14;
ifp->recv_queue.head = 0;
return ethsz;
#if 0
default:
MG_DEBUG(("unknown PPP frame:"));
mg_hexdump(ppp->buf, ppp->bufsz);
#endif
}
ifp->recv_queue.head = 0;
return 0;
(void) ethlen;
}
struct mg_tcpip_driver mg_tcpip_driver_ppp = {mg_ppp_init, mg_ppp_tx, mg_ppp_rx,
mg_ppp_poll};
#endif
src/drivers/ppp.h
-11
View File
@@ -1,11 +0,0 @@
#pragma once
struct mg_tcpip_driver_ppp_data {
void *uart; // Opaque UART bus descriptor
void (*reset)(void *); // Modem hardware reset
void (*tx)(void *, uint8_t); // UART transmit single byte
int (*rx)(void *); // UART receive single byte
const char **script; // List of AT commands and expected replies
int script_index; // Index of the current AT command in the list
uint64_t deadline; // AT command deadline in ms
};