diff options
| -rw-r--r-- | accel-pppd/accel-ppp.conf.5 | 14 | ||||
| -rw-r--r-- | accel-pppd/extra/metrics.c | 59 |
2 files changed, 71 insertions, 2 deletions
diff --git a/accel-pppd/accel-ppp.conf.5 b/accel-pppd/accel-ppp.conf.5 index feb9214e..076f7137 100644 --- a/accel-pppd/accel-ppp.conf.5 +++ b/accel-pppd/accel-ppp.conf.5 @@ -1328,6 +1328,20 @@ When the option is missing or empty, all peers are allowed. Peers that do not match a CIDR have their connection closed immediately after .BR accept (2). +.TP +.BI "read_timeout=" seconds +Maximum time a client may take to deliver a complete HTTP request. +Connections that have not produced a terminating +.BR \(dq\\r\\n\\r\\n\(dq +within this deadline are closed. Defaults to 5 seconds. Set to +.B 0 +to disable the deadline. +.TP +.BI "max_clients=" n +Maximum number of in-flight HTTP clients. Excess connections are +accepted then immediately closed. Defaults to 64. Set to +.B 0 +to disable the cap. .SH [connlimit] .br This module limits connection rate from single source. diff --git a/accel-pppd/extra/metrics.c b/accel-pppd/extra/metrics.c index d0fbe6e5..78774dd0 100644 --- a/accel-pppd/extra/metrics.c +++ b/accel-pppd/extra/metrics.c @@ -45,10 +45,13 @@ enum metrics_format { }; #define METRICS_RECV_BUF_SIZE 2048 +#define METRICS_DEFAULT_READ_TIMEOUT 5 /* seconds */ +#define METRICS_DEFAULT_MAX_CLIENTS 64 struct metrics_client_t { struct list_head entry; struct triton_md_handler_t hnd; + struct triton_timer_t timer; struct sockaddr_in addr; char *recv_buf; int recv_pos; @@ -64,10 +67,15 @@ struct metrics_acl_t { static enum metrics_format conf_format = METRICS_FORMAT_PROMETHEUS; static char *conf_address; static LIST_HEAD(conf_allowed); +static int conf_read_timeout = METRICS_DEFAULT_READ_TIMEOUT; +static int conf_max_clients = METRICS_DEFAULT_MAX_CLIENTS; + +#define METRICS_ACCEPT_BATCH 16 /* max accept()s per serv_read tick */ static struct triton_context_t serv_ctx; static struct triton_md_handler_t serv_hnd; static LIST_HEAD(clients); +static unsigned int client_count; static int serv_running; static int parse_format(const char *opt, enum metrics_format *out) @@ -304,6 +312,18 @@ static int load_config(void) free_acl(&conf_allowed); list_replace_init(&new_allowed, &conf_allowed); + opt = conf_get_opt("metrics", "read_timeout"); + if (opt) { + int n = atoi(opt); + conf_read_timeout = n > 0 ? n : 0; + } + + opt = conf_get_opt("metrics", "max_clients"); + if (opt) { + int n = atoi(opt); + conf_max_clients = n > 0 ? n : 0; + } + return 0; } @@ -717,15 +737,27 @@ out: strbuf_free(&sb); } +static void client_timeout(struct triton_timer_t *t); + static void disconnect_client(struct metrics_client_t *cln) { + if (cln->timer.tpd) + triton_timer_del(&cln->timer); list_del(&cln->entry); + client_count--; triton_md_unregister_handler(&cln->hnd, 1); if (cln->recv_buf) _free(cln->recv_buf); _free(cln); } +static void client_timeout(struct triton_timer_t *t) +{ + struct metrics_client_t *cln = container_of(t, typeof(*cln), timer); + + disconnect_client(cln); +} + static void handle_request(struct metrics_client_t *cln) { char *line_end, *space1, *space2; @@ -807,8 +839,19 @@ static int serv_read(struct triton_md_handler_t *h) socklen_t size = sizeof(addr); int sock; struct metrics_client_t *cln; - - while (1) { + int batch; + + /* Cap the number of accepts handled per dispatch. Without this, an + * overflow burst (peers exceeding max_clients or denied by + * allowed_ips) keeps us in this loop accept()ing and immediately + * closing sockets, never yielding back to the triton dispatcher. + * Since the per-client read-timeout timers share serv_ctx, that + * would delay client_timeout() and let stalled clients live past + * read_timeout. Return after METRICS_ACCEPT_BATCH iterations; if + * the listening fd is still readable triton will dispatch us again + * on the next loop after timers have had a chance to fire. + */ + for (batch = 0; batch < METRICS_ACCEPT_BATCH; batch++) { sock = accept(h->fd, (struct sockaddr *)&addr, &size); if (sock < 0) { if (errno == EAGAIN) @@ -822,6 +865,11 @@ static int serv_read(struct triton_md_handler_t *h) continue; } + if (conf_max_clients && client_count >= (unsigned int)conf_max_clients) { + close(sock); + continue; + } + if (fcntl(sock, F_SETFL, O_NONBLOCK)) { log_error("metrics: failed to set nonblocking mode: %s\n", strerror(errno)); close(sock); @@ -845,8 +893,15 @@ static int serv_read(struct triton_md_handler_t *h) } list_add_tail(&cln->entry, &clients); + client_count++; triton_md_register_handler(&serv_ctx, &cln->hnd); triton_md_enable_handler(&cln->hnd, MD_MODE_READ); + + if (conf_read_timeout > 0) { + cln->timer.expire = client_timeout; + cln->timer.expire_tv.tv_sec = conf_read_timeout; + triton_timer_add(&serv_ctx, &cln->timer, 0); + } } return 0; |