From b314737e9a0f0df710ba5e8691882cd7d42faaf5 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sun, 16 Oct 2011 00:42:29 +0200 Subject: [PATCH] detach stdin/stdout/stderr from child processes, implement a separate logging pipe and relay log messages with prefix --- main.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++--- netifd.h | 9 +++++ proto-shell.c | 3 ++ 3 files changed, 114 insertions(+), 5 deletions(-) diff --git a/main.c b/main.c index 6419fe9..b07784e 100644 --- a/main.c +++ b/main.c @@ -3,6 +3,7 @@ #include #include #include +#include #include "netifd.h" #include "ubus.h" @@ -18,12 +19,84 @@ static char **global_argv; static struct list_head process_list = LIST_HEAD_INIT(process_list); static struct list_head fds = LIST_HEAD_INIT(fds); +static void +netifd_delete_process(struct netifd_process *proc) +{ + if (proc->uloop.pending) + uloop_process_delete(&proc->uloop); + list_del(&proc->list); + netifd_fd_delete(&proc->log_fd); +} + +static void +netifd_process_log_cb(struct uloop_fd *fd, unsigned int events) +{ + struct netifd_process *proc; + const char *log_prefix; + char *buf, *cur; + int maxlen, len, read_len; + + proc = container_of(fd, struct netifd_process, log_uloop); + + if (!proc->log_buf) + proc->log_buf = malloc(LOG_BUF_SIZE + 1); + + buf = proc->log_buf + proc->log_buf_ofs; + maxlen = LOG_BUF_SIZE - proc->log_buf_ofs; + + log_prefix = proc->log_prefix; + if (!log_prefix) + log_prefix = "process"; + +retry: + read_len = len = read(fd->fd, buf, maxlen); + if (len <= 0) { + if (errno == EINTR) + goto retry; + + return; + } + proc->log_buf_ofs += len; + + cur = buf; + buf = proc->log_buf; + while ((cur = memchr(cur, '\n', len))) { + *cur = 0; + + if (!proc->log_overflow) + fprintf(stderr, "%s (%d): %s\n", log_prefix, proc->uloop.pid, buf); + else + proc->log_overflow = false; + + cur++; + len -= cur - buf; + buf = cur; + } + + if (buf > proc->log_buf && len > 0) + memmove(buf, proc->log_buf, len); + + if (len == LOG_BUF_SIZE) { + if (!proc->log_overflow) { + proc->log_buf[LOG_BUF_SIZE] = 0; + fprintf(stderr, "%s (%d): %s [...]\n", log_prefix, proc->uloop.pid, proc->log_buf); + proc->log_overflow = true; + } + len = 0; + } + proc->log_buf_ofs = len; + + if (read_len == maxlen) + goto retry; +} + static void netifd_process_cb(struct uloop_process *proc, int ret) { struct netifd_process *np; np = container_of(proc, struct netifd_process, uloop); - list_del(&np->list); + netifd_process_log_cb(&np->log_uloop, 0); + netifd_delete_process(np); return np->cb(np, ret); } @@ -31,13 +104,17 @@ int netifd_start_process(const char **argv, char **env, struct netifd_process *proc) { struct netifd_fd *fd; + int pfds[2]; int pid; netifd_kill_process(proc); - if ((pid = fork()) < 0) + if (pipe(pfds) < 0) return -1; + if ((pid = fork()) < 0) + goto error; + if (!pid) { if (env) { while (*env) { @@ -55,19 +132,37 @@ netifd_start_process(const char **argv, char **env, struct netifd_process *proc) close(fd->fd); } + dup2(pfds[1], 0); + dup2(pfds[1], 1); + dup2(pfds[1], 2); + + close(pfds[0]); + close(pfds[1]); + execvp(argv[0], (char **) argv); exit(127); } if (pid < 0) - return -1; + goto error; + close(pfds[1]); proc->uloop.cb = netifd_process_cb; proc->uloop.pid = pid; uloop_process_add(&proc->uloop); list_add_tail(&proc->list, &process_list); + proc->log_uloop.fd = proc->log_fd.fd = pfds[0]; + proc->log_uloop.cb = netifd_process_log_cb; + netifd_fd_add(&proc->log_fd); + uloop_fd_add(&proc->log_uloop, ULOOP_EDGE_TRIGGER | ULOOP_READ); + return 0; + +error: + close(pfds[0]); + close(pfds[1]); + return -1; } void @@ -77,8 +172,7 @@ netifd_kill_process(struct netifd_process *proc) return; kill(proc->uloop.pid, SIGTERM); - uloop_process_delete(&proc->uloop); - list_del(&proc->list); + netifd_delete_process(proc); } void @@ -151,6 +245,9 @@ netifd_setup_signals(void) sigaction(SIGTERM, &s, NULL); sigaction(SIGUSR1, &s, NULL); sigaction(SIGUSR2, &s, NULL); + + s.sa_handler = SIG_IGN; + sigaction(SIGPIPE, &s, NULL); } static void diff --git a/netifd.h b/netifd.h index 4129af7..316c746 100644 --- a/netifd.h +++ b/netifd.h @@ -44,6 +44,8 @@ enum { #define D(level, format, ...) no_debug(DEBUG_ ## level, format, ## __VA_ARGS__) #endif +#define LOG_BUF_SIZE 256 + static inline void no_debug(int level, const char *fmt, ...) { } @@ -59,6 +61,13 @@ struct netifd_process { struct uloop_process uloop; void (*cb)(struct netifd_process *, int ret); int dir_fd; + + struct netifd_fd log_fd; + struct uloop_fd log_uloop; + const char *log_prefix; + char *log_buf; + int log_buf_ofs; + bool log_overflow; }; int netifd_start_process(const char **argv, char **env, struct netifd_process *proc); diff --git a/proto-shell.c b/proto-shell.c index c0af99f..68af69b 100644 --- a/proto-shell.c +++ b/proto-shell.c @@ -470,10 +470,13 @@ proto_shell_attach(const struct proto_handler *h, struct interface *iface, state->setup_timeout.cb = proto_shell_setup_timeout_cb; state->setup_task.cb = proto_shell_setup_cb; state->setup_task.dir_fd = proto_fd.fd; + state->setup_task.log_prefix = iface->name; state->teardown_task.cb = proto_shell_teardown_cb; state->teardown_task.dir_fd = proto_fd.fd; + state->teardown_task.log_prefix = iface->name; state->proto_task.cb = proto_shell_task_cb; state->proto_task.dir_fd = proto_fd.fd; + state->proto_task.log_prefix = iface->name; state->handler = container_of(h, struct proto_shell_handler, proto); return &state->proto; -- 2.25.1