From 09f1abfe18258807c412bce88ad459984add0cd3 Mon Sep 17 00:00:00 2001 From: David Härdeman Date: Tue, 9 Jun 2020 20:51:44 +0200 Subject: Add an rcon shutdown method --- rcon.c | 425 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 425 insertions(+) create mode 100644 rcon.c (limited to 'rcon.c') diff --git a/rcon.c b/rcon.c new file mode 100644 index 0000000..756d480 --- /dev/null +++ b/rcon.c @@ -0,0 +1,425 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "main.h" +#include "uring.h" +#include "config.h" +#include "server.h" +#include "rcon.h" + +struct rcon { + struct server *server; + struct uring_task task; + unsigned next_rcon; + struct sockaddr_in46 rcon; + char rconstr[ADDRSTRLEN]; + char rconbuf[4096]; + size_t rconbuflen; + size_t rconbufdone; +}; + +static void +rcon_free(struct uring_task *task) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + fprintf(stderr, "%s: called with task 0x%p and idle 0x%p\n", __func__, task, rcon); + rcon->server->rcon = NULL; + free(rcon); +} + +void +rcon_refdump(struct rcon *rcon) +{ + if (!rcon) + return; + + uring_task_refdump(&rcon->task); +} + +void +rcon_delete(struct cfg *cfg, struct server *server) +{ + struct rcon *rcon = server->rcon; + + if (!rcon) + return; + + fprintf(stderr, "%s called, closing fd %i\n", __func__, rcon->task.fd); + uring_cancel(cfg, &rcon->task); + uring_task_put(cfg, &rcon->task); + server->rcon = NULL; +} + +static int32_t +read_int(char **pos, size_t *len) +{ + uint32_t val; + char *p = *pos; + + if (len && *len < 4) + return 0; + + val = ((uint8_t)p[0] << 0); + val += ((uint8_t)p[1] << 8); + val += ((uint8_t)p[2] << 16); + val += ((uint8_t)p[3] << 24); + + *pos += 4; + if (len) + *len -= 4; + + return (int32_t)val; +} + +static void +write_int(char **pos, size_t *len, int32_t orig) +{ + uint32_t val = (uint32_t)orig; + char *p = *pos; + + p[0] = (val >> 0) & 0xff; + p[1] = (val >> 8) & 0xff; + p[2] = (val >> 16) & 0xff; + p[3] = (val >> 24) & 0xff; + *pos += 4; + if (len) + *len += 4; +} + +static void +write_str(char **pos, size_t *len, const char *str) +{ + size_t towrite = strlen(str); + + memcpy(*pos, str, towrite); + *pos += towrite; + if (len) + *len += towrite; +} + +static void +write_end(char **pos, size_t *len) +{ + char *p = *pos; + + p[0] = 0x00; + p[1] = 0x00; + *pos += 2; + if (len) + *len += 2; +} + +enum rcon_packet_type { + RCON_PACKET_LOGIN = 3, + RCON_PACKET_LOGIN_OK = 2, + RCON_PACKET_LOGIN_FAIL = -1, + RCON_PACKET_COMMAND = 2, + RCON_PACKET_RESPONSE = 0, +}; + +static void +create_packet(struct cfg *cfg, struct rcon *rcon, int32_t reqid, enum rcon_packet_type type, const char *msg) +{ + char *pos = &rcon->rconbuf[4]; + + rcon->rconbufdone = 0; + rcon->rconbuflen = 4; + write_int(&pos, &rcon->rconbuflen, reqid); + write_int(&pos, &rcon->rconbuflen, type); + write_str(&pos, &rcon->rconbuflen, msg); + write_end(&pos, &rcon->rconbuflen); + pos = &rcon->rconbuf[0]; + write_int(&pos, NULL, rcon->rconbuflen - 4); + + fprintf(stderr, "Created packet (reqid: %" PRIi32 ", type %" PRIi32 ", len %zu, payload: %s)\n", + reqid, type, rcon->rconbuflen, msg); +} + +static bool +packet_complete(struct cfg *cfg, struct rcon *rcon) +{ + char *pos = rcon->rconbuf; + size_t len = rcon->rconbufdone; + int32_t plen; + + if (rcon->rconbufdone < 14) + return false; + + plen = read_int(&pos, &len); + fprintf(stderr, "Reply is %zu bytes, packet size %" PRIi32 "\n", rcon->rconbufdone, plen + 4); + if (rcon->rconbufdone < plen + 4) + return false; + else + return true; +} + +static bool +read_packet(struct cfg *cfg, struct rcon *rcon, int32_t *id, int32_t *type, char **rmsg) +{ + char *pos = rcon->rconbuf; + size_t len = rcon->rconbufdone; + int32_t plen; + + plen = read_int(&pos, &len); + *id = read_int(&pos, &len); + *type = read_int(&pos, &len); + *rmsg = NULL; + + if (plen < 10) { + fprintf(stderr, "Invalid packet length: %" PRIi32 "\n", plen); + return false; + } + + fprintf(stderr, "Remaining = %zu\n", len); + if (len > 2) { + char *msg; + + msg = malloc(len - 1); + if (!msg) { + perror("malloc"); + return false; + } + + memcpy(msg, pos, len - 2); + msg[len - 2] = '\0'; + + *rmsg = msg; + pos += len - 2; + len = 2; + } + + if (len < 2) { + fprintf(stderr, "Short message\n"); + return false; + } + + if (pos[0] != '\0' || pos[1] != '\0') { + fprintf(stderr, "Invalid trailer\n"); + return false; + } + + fprintf(stderr, "Response - len: %" PRIi32 ", id: %" PRIi32 + ", type: %" PRIi32 ", msg: %s\n", + plen, *id, *type, *rmsg); + + return true; +} + +static void +rcon_stop_reply(struct cfg *cfg, struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + int32_t id; + int32_t type; + char *msg; + + fprintf(stderr, "%s: result %i\n", __func__, res); + if (res < 0) + goto out; + + rcon->rconbufdone += res; + + /* FIXME: could be multiple packets */ + if (packet_complete(cfg, rcon)) { + fprintf(stderr, "Packet complete\n"); + read_packet(cfg, rcon, &id, &type, &msg); + if (id != 2) { + fprintf(stderr, "RCon stop cmd failed - unexpected reply id (%" PRIi32 ")\n", id); + goto out; + } else if (type != RCON_PACKET_RESPONSE) { + fprintf(stderr, "RCon stop cmd failed - unexpected reply type (%" PRIi32 ")\n", type); + goto out; + } + fprintf(stderr, "RCon stop successful (%s)\n", msg); + free(msg); + + } else { + fprintf(stderr, "Packet not complete\n"); + uring_read(cfg, &rcon->task, &rcon->rconbuf + rcon->rconbufdone, + sizeof(rcon->rconbuf) - rcon->rconbufdone, 0, rcon_stop_reply); + } + +out: + uring_task_put(cfg, &rcon->task); +} + +static void +rcon_stop_sent(struct cfg *cfg, struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + fprintf(stderr, "%s: result %i\n", __func__, res); + if (res < 0) { + uring_task_put(cfg, &rcon->task); + return; + } + + rcon->rconbufdone += res; + if (rcon->rconbufdone < rcon->rconbuflen) { + uring_write(cfg, &rcon->task, rcon->rconbuf + rcon->rconbufdone, + rcon->rconbuflen - rcon->rconbufdone, rcon_stop_sent); + return; + } + + fprintf(stderr, "%s: stop cmd sent\n", __func__); + rcon->rconbufdone = 0; + rcon->rconbuflen = 0; + uring_read(cfg, &rcon->task, &rcon->rconbuf, sizeof(rcon->rconbuf), 0, rcon_stop_reply); +} + +static void +rcon_login_reply(struct cfg *cfg, struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + int32_t id; + int32_t type; + char *msg; + + fprintf(stderr, "%s: result %i\n", __func__, res); + if (res < 0) + goto out; + + rcon->rconbufdone += res; + + if (packet_complete(cfg, rcon)) { + fprintf(stderr, "Packet complete\n"); + read_packet(cfg, rcon, &id, &type, &msg); + if (id != 1) { + fprintf(stderr, "RCon login failed - unexpected reply id (%" PRIi32 ")\n", id); + goto out; + } else if (type == RCON_PACKET_LOGIN_FAIL) { + fprintf(stderr, "RCon login failed - incorrect password\n"); + goto out; + } else if (type != RCON_PACKET_LOGIN_OK) { + fprintf(stderr, "RCon login failed - unexpected reply type (%" PRIi32 ")\n", type); + goto out; + } + free(msg); + fprintf(stderr, "RCon login successful\n"); + create_packet(cfg, rcon, 2, RCON_PACKET_COMMAND, "stop"); + uring_write(cfg, &rcon->task, rcon->rconbuf, rcon->rconbuflen, rcon_stop_sent); + + } else { + fprintf(stderr, "Packet not complete\n"); + uring_read(cfg, &rcon->task, &rcon->rconbuf + rcon->rconbufdone, + sizeof(rcon->rconbuf) - rcon->rconbufdone, 0, rcon_login_reply); + } + + return; + +out: + uring_task_put(cfg, &rcon->task); +} + +static void +rcon_login_sent(struct cfg *cfg, struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + fprintf(stderr, "%s: result %i\n", __func__, res); + if (res < 0) { + uring_task_put(cfg, &rcon->task); + return; + } + + rcon->rconbufdone += res; + if (rcon->rconbufdone < rcon->rconbuflen) { + uring_write(cfg, &rcon->task, rcon->rconbuf + rcon->rconbufdone, + rcon->rconbuflen - rcon->rconbufdone, rcon_login_sent); + return; + } + + fprintf(stderr, "%s: login sent\n", __func__); + rcon->rconbufdone = 0; + rcon->rconbuflen = 0; + uring_read(cfg, &rcon->task, &rcon->rconbuf, sizeof(rcon->rconbuf), 0, rcon_login_reply); +} + +static void rcon_connect_next_rcon(struct cfg *cfg, struct rcon *rcon); + +static void +rcon_connected(struct cfg *cfg, struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + fprintf(stderr, "%s: connected %i\n", __func__, res); + if (res < 0) { + rcon_connect_next_rcon(cfg, rcon); + return; + } + + create_packet(cfg, rcon, 1, RCON_PACKET_LOGIN, rcon->server->rcon_password); + uring_write(cfg, &rcon->task, rcon->rconbuf, rcon->rconbuflen, rcon_login_sent); +} + +/* FIXME: Parts of this could be shared with proxy.c, probably in server.c */ +static void +rcon_connect_next_rcon(struct cfg *cfg, struct rcon *rcon) +{ + struct sockaddr_in46 *remote, *tmp; + struct server *scfg = rcon->server; + int sfd; + unsigned i = 0; + +again: + remote = NULL; + list_for_each_entry(tmp, &scfg->rcons, list) { + if (i == rcon->next_rcon) { + remote = tmp; + break; + } + i++; + } + + if (!remote) { + fprintf(stderr, "No more rcon addresses to attempt\n"); + uring_task_put(cfg, &rcon->task); + return; + } + + rcon->next_rcon++; + rcon->rcon = *remote; + sockaddr_to_str(&rcon->rcon, rcon->rconstr, sizeof(rcon->rconstr)); + fprintf(stderr, "%s: attempting rcon connection to %s (len %u)\n", + scfg->name, rcon->rconstr, rcon->rcon.addrlen); + + sfd = socket(rcon->rcon.storage.ss_family, SOCK_STREAM, 0); + if (sfd < 0) { + perror("socket"); + goto again; + } + + uring_task_set_fd(&rcon->task, sfd); + uring_connect(cfg, &rcon->task, &rcon->rcon, rcon_connected); +} + +void +rcon_init(struct cfg *cfg, struct server *server) +{ + struct rcon *rcon; + + if (!server) + return; + + if (list_empty(&server->rcons) || !server->rcon_password) + return; + + rcon = zmalloc(sizeof(*rcon)); + if (!rcon) + perrordie("malloc"); + + uring_task_init(&rcon->task, "rcon", &server->task, rcon_free); + rcon->server = server; + server->rcon = rcon; + + rcon_connect_next_rcon(cfg, rcon); +} -- cgit v1.2.3