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#include "common.h"
extern struct uwsgi_tuntap utt;
// error reporting
void uwsgi_tuntap_error_do(struct uwsgi_tuntap_peer *uttp, char *msg, char *file, int line) {
if (uttp) {
uwsgi_log_verbose("[tuntap] peer fd: %d ip: %s %s: %s [%s line %d]\n", uttp->fd, uttp->ip, msg, strerror(errno), file, line);
}
else {
uwsgi_log_verbose("[tuntap] %s: %s [%s line %d]\n", msg, strerror(errno), file, line);
}
}
// create a new peer
struct uwsgi_tuntap_peer *uwsgi_tuntap_peer_create(struct uwsgi_tuntap_router *uttr, int fd, int is_router) {
struct uwsgi_tuntap_peer *uttp = uwsgi_calloc(sizeof(struct uwsgi_tuntap_peer));
uttp->fd = fd;
// leave space fot he uwsgi header
uttp->buf = uwsgi_malloc(utt.buffer_size + 4);
uttp->write_buf = uwsgi_malloc(utt.buffer_size);
if (uttr->peers_tail) {
uttr->peers_tail->next = uttp;
uttp->prev = uttr->peers_tail;
uttr->peers_tail = uttp;
}
else {
uttr->peers_head = uttp;
uttr->peers_tail = uttp;
}
if (!is_router) {
if (utt.use_credentials) {
uwsgi_log_verbose("[uwsgi-tuntap] waiting for privileges drop...\n");
for(;;) {
if (getuid() > 0) break;
sleep(1);
}
uwsgi_log_verbose("[uwsgi-tuntap] privileges dropped\n");
if (uwsgi_pass_cred(fd, "uwsgi-tuntap", 12)) {
// better to exit
exit(1);
}
}
uwsgi_tuntap_peer_send_rules(fd, uttp);
}
return uttp;
}
// destroy a peer
void uwsgi_tuntap_peer_destroy(struct uwsgi_tuntap_router *uttr, struct uwsgi_tuntap_peer *uttp) {
struct uwsgi_tuntap_peer *prev = uttp->prev;
struct uwsgi_tuntap_peer *next = uttp->next;
if (prev) {
prev->next = next;
}
if (next) {
next->prev = prev;
}
if (uttp == uttr->peers_head) {
uttr->peers_head = next;
}
if (uttp == uttr->peers_tail) {
uttr->peers_tail = prev;
}
free(uttp->buf);
free(uttp->write_buf);
if (uttp->rules) free(uttp->rules);
close(uttp->fd);
free(uttp);
}
// get a peer by addr
struct uwsgi_tuntap_peer *uwsgi_tuntap_peer_get_by_addr(struct uwsgi_tuntap_router *uttr, uint32_t addr) {
struct uwsgi_tuntap_peer *uttp = uttr->peers_head;
while (uttp) {
if (uttp->addr == addr)
return uttp;
uttp = uttp->next;
}
return NULL;
}
// block all reading peers
void uwsgi_tuntap_block_reads(struct uwsgi_tuntap_router *uttr) {
struct uwsgi_tuntap_peer *uttp = uttr->peers_head;
while (uttp) {
if (!uttp->blocked_read) {
if (!uttp->wait_for_write) {
if (event_queue_del_fd(uttr->queue, uttp->fd, event_queue_read())) {
struct uwsgi_tuntap_peer *tmp_uttp = uttp;
uttp = uttp->next;
uwsgi_tuntap_peer_destroy(uttr, tmp_uttp);
continue;
}
}
else {
if (event_queue_fd_readwrite_to_write(uttr->queue, uttp->fd)) {
struct uwsgi_tuntap_peer *tmp_uttp = uttp;
uttp = uttp->next;
uwsgi_tuntap_peer_destroy(uttr, tmp_uttp);
continue;
}
}
uttp->blocked_read = 1;
}
uttp = uttp->next;
}
}
//unblock all reading peers
void uwsgi_tuntap_unblock_reads(struct uwsgi_tuntap_router *uttr) {
struct uwsgi_tuntap_peer *uttp = uttr->peers_head;
while (uttp) {
if (uttp->blocked_read) {
if (!uttp->wait_for_write) {
if (event_queue_add_fd_read(uttr->queue, uttp->fd)) {
struct uwsgi_tuntap_peer *tmp_uttp = uttp;
uttp = uttp->next;
uwsgi_tuntap_peer_destroy(uttr, tmp_uttp);
continue;
}
}
else {
if (event_queue_fd_write_to_readwrite(uttr->queue, uttp->fd)) {
struct uwsgi_tuntap_peer *tmp_uttp = uttp;
uttp = uttp->next;
uwsgi_tuntap_peer_destroy(uttr, tmp_uttp);
continue;
}
}
uttp->blocked_read = 0;
}
uttp = uttp->next;
}
}
// enqueue a packet in the tuntap device
void uwsgi_tuntap_enqueue(struct uwsgi_tuntap_router *uttr) {
ssize_t rlen = write(uttr->fd, uttr->write_buf + uttr->write_pos, uttr->write_pktsize - uttr->write_pos);
// error on the tuntap device, destroy !!!
if (rlen == 0) {
uwsgi_error("uwsgi_tuntap_enqueue()/write()");
exit(1);
}
if (rlen < 0) {
if (uwsgi_is_again())
goto retry;
uwsgi_error("uwsgi_tuntap_enqueue()/write()");
exit(1);
}
uttr->write_pos += rlen;
if (uttr->write_pos >= uttr->write_pktsize) {
uttr->write_pos = 0;
if (uttr->wait_for_write) {
if (event_queue_fd_write_to_read(uttr->queue, uttr->fd)) {
uwsgi_error("uwsgi_tuntap_enqueue()/event_queue_fd_read_to_write()");
exit(1);
}
uttr->wait_for_write = 0;
}
uwsgi_tuntap_unblock_reads(uttr);
return;
}
retry:
if (!uttr->wait_for_write) {
uwsgi_tuntap_block_reads(uttr);
if (event_queue_fd_read_to_write(uttr->queue, uttr->fd)) {
uwsgi_error("uwsgi_tuntap_enqueue()/event_queue_fd_read_to_write()");
exit(1);
}
uttr->wait_for_write = 1;
}
}
int uwsgi_tuntap_register_addr(struct uwsgi_tuntap_router *uttr, struct uwsgi_tuntap_peer *uttp) {
struct uwsgi_tuntap_peer *tmp_uttp = uwsgi_tuntap_peer_get_by_addr(uttr, uttp->addr);
char ip[INET_ADDRSTRLEN + 1];
memset(ip, 0, INET_ADDRSTRLEN + 1);
if (!inet_ntop(AF_INET, &uttp->addr, ip, INET_ADDRSTRLEN)) {
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_register_addr()/inet_ntop()");
return -1;
}
if (uttp != tmp_uttp) {
uwsgi_log("[tuntap-router] detected ip collision for %s\n", ip);
uwsgi_tuntap_peer_destroy(uttr, tmp_uttp);
}
uwsgi_log("[tuntap-router] registered new peer %s (fd: %d)\n", ip, uttp->fd);
memcpy(uttp->ip, ip, INET_ADDRSTRLEN + 1);
return 0;
}
// receive a packet from the client
int uwsgi_tuntap_peer_dequeue(struct uwsgi_tuntap_router *uttr, struct uwsgi_tuntap_peer *uttp, int is_router) {
// get body
if (uttp->header_pos >= 4) {
ssize_t rlen = read(uttp->fd, uttp->buf + uttp->buf_pos, uttp->buf_pktsize - uttp->buf_pos);
if (rlen == 0)
return -1;
if (rlen < 0) {
if (uwsgi_is_again())
return 0;
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_dequeue()/read()");
return -1;
}
uttp->buf_pos += rlen;
uttp->rx += rlen;
// a whole pkt has been received
if (uttp->buf_pos >= uttp->buf_pktsize) {
uttp->header_pos = 0;
uttp->buf_pos = 0;
if (!is_router) goto enqueue;
// a rule block
if (uttp->header[3] == 1) {
if (uttp->rules) free(uttp->rules);
uttp->rules = uwsgi_malloc(uttp->buf_pktsize);
memcpy(uttp->rules, uttp->buf, uttp->buf_pktsize);
uttp->rules_cnt = uttp->buf_pktsize / sizeof(struct uwsgi_tuntap_peer_rule);
return 0;
}
if (uwsgi_tuntap_firewall_check(utt.fw_out, uttp->buf, uttp->buf_pktsize)) return 0;
// if there is no associated address store the source
if (!uttp->addr) {
// close on invalid first packet
if (uttp->buf_pktsize < 20) return -1;
uint32_t *src_ip = (uint32_t *) (&uttp->buf[12]);
uttp->addr = *src_ip;
// drop invalid ip addresses
if (!uttp->addr)
return -1;
if (uwsgi_tuntap_register_addr(uttr, uttp)) {
return -1;
}
}
if (uwsgi_tuntap_peer_rules_check(uttr, uttp, uttp->buf, uttp->buf_pktsize, 1)) return 0;
// check four routing rule
if (uttr->gateway_fd > -1) {
if (uwsgi_tuntap_route_check(uttr->gateway_fd, uttp->buf, uttp->buf_pktsize)) return 0;
}
enqueue:
memcpy(uttr->write_buf, uttp->buf, uttp->buf_pktsize);
uttr->write_pktsize = uttp->buf_pktsize;
uwsgi_tuntap_enqueue(uttr);
}
return 0;
}
ssize_t rlen = read(uttp->fd, uttp->header + uttp->header_pos, 4 - uttp->header_pos);
if (rlen == 0)
return -1;
if (rlen < 0) {
if (uwsgi_is_again())
return 0;
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_dequeue()/read()");
return -1;
}
uttp->header_pos += rlen;
if (uttp->header_pos >= 4) {
uint16_t *pktsize = (uint16_t *) &uttp->header[1];
uttp->buf_pktsize = *pktsize;
uttp->rx += 4;
}
return 0;
}
// enqueue a packet to the client
int uwsgi_tuntap_peer_enqueue(struct uwsgi_tuntap_router *uttr, struct uwsgi_tuntap_peer *uttp) {
ssize_t rlen = write(uttp->fd, uttp->write_buf + uttp->written, uttp->write_buf_pktsize - uttp->written);
if (rlen == 0) {
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_enqueue()/write()");
return -1;
}
if (rlen < 0) {
if (uwsgi_is_again())
goto retry;
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_enqueue()/write()");
return -1;
}
uttp->written += rlen;
uttp->tx += rlen;
if (uttp->written >= uttp->write_buf_pktsize) {
uttp->written = 0;
uttp->write_buf_pktsize = 0;
if (uttp->wait_for_write) {
// if the write ends while we are writing to the tuntap, block the reads
if (uttr->wait_for_write) {
uttp->blocked_read = 1;
if (event_queue_del_fd(uttr->queue, uttp->fd, event_queue_write())) {
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_enqueue()/event_queue_del_fd()");
return -1;
}
}
else {
if (event_queue_fd_readwrite_to_read(uttr->queue, uttp->fd)) {
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_enqueue()/event_queue_fd_write_to_read()");
return -1;
}
}
uttp->wait_for_write = 0;
}
return 0;
}
memmove(uttp->write_buf, uttp->write_buf + rlen, uttp->write_buf_pktsize - rlen);
uttp->write_buf_pktsize -= rlen;
retry:
if (!uttp->wait_for_write) {
if (event_queue_fd_read_to_readwrite(uttr->queue, uttp->fd)) {
uwsgi_tuntap_error(uttp, "uwsgi_tuntap_peer_enqueue()/event_queue_fd_read_to_write()");
return -1;
}
uttp->wait_for_write = 1;
}
return 0;
}
int uwsgi_tuntap_device(char *name) {
struct ifreq ifr;
int fd = open(UWSGI_TUNTAP_DEVICE, O_RDWR);
if (fd < 0) {
uwsgi_error_open(UWSGI_TUNTAP_DEVICE);
exit(1);
}
memset(&ifr, 0, sizeof(struct ifreq));
ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
strncpy(ifr.ifr_name, name, IFNAMSIZ);
if (ioctl(fd, TUNSETIFF, (void *) &ifr) < 0) {
uwsgi_error("uwsgi_tuntap_device()/ioctl()");
exit(1);
}
uwsgi_log("initialized tuntap device %s (fd: %d)\n", ifr.ifr_name, fd);
return fd;
}
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