diff options
Diffstat (limited to 'src/net.c')
| -rw-r--r-- | src/net.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/net.c b/src/net.c new file mode 100644 index 0000000..856b120 --- /dev/null +++ b/src/net.c @@ -0,0 +1,278 @@ +#include "net.h" +#include "log.h" + +#include <netdb.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> + +#define gai_print_errno(ec) print_error("getaddrinfo: %s\n", gai_strerror(ec)) + +static int ignore_signal(int signum) +{ + int ret = 0; + struct sigaction act; + memset(&act, 0, sizeof(act)); + act.sa_handler = SIG_IGN; + + ret = sigaction(signum, &act, NULL); + if (ret < 0) { + print_errno("sigaction"); + return ret; + } + + return ret; +} + +static int ignore_sigchld() +{ + return ignore_signal(SIGCHLD); +} + +int bind_to_port(const char *port) +{ + struct addrinfo *result, *it = NULL; + struct addrinfo hints; + int socket_fd, ret = 0; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + hints.ai_flags = AI_PASSIVE; + + ret = getaddrinfo(NULL, port, &hints, &result); + if (ret) { + gai_print_errno(ret); + return -1; + } + + for (it = result; it; it = it->ai_next) { + socket_fd = socket(it->ai_family, it->ai_socktype, it->ai_protocol); + if (socket_fd < 0) { + print_errno("socket"); + continue; + } + + static const int yes = 1; + + if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) == -1) { + print_errno("setsockopt"); + goto close_socket; + } + + if (bind(socket_fd, it->ai_addr, it->ai_addrlen) < 0) { + print_errno("bind"); + goto close_socket; + } + + break; + + close_socket: + close(socket_fd); + } + + freeaddrinfo(result); + + if (!it) { + print_error("Couldn't bind to port %s\n", port); + return -1; + } + + ret = listen(socket_fd, 4096); + if (ret < 0) { + print_errno("listen"); + goto fail; + } + + /* Don't make zombies. The alternative is wait()ing for the child in + * the signal handler. */ + ret = ignore_sigchld(); + if (ret < 0) + goto fail; + + return socket_fd; + +fail: + close(socket_fd); + + return ret; +} + +int accept_connection(int fd, connection_handler handler, void *arg) +{ + int conn_fd, ret = 0; + + ret = accept(fd, NULL, NULL); + if (ret < 0) { + print_errno("accept"); + return ret; + } + conn_fd = ret; + + pid_t child_pid = fork(); + if (child_pid < 0) { + print_errno("fork"); + ret = -1; + goto close_conn; + } + + if (!child_pid) { + close(fd); + ret = handler(conn_fd, arg); + close(conn_fd); + exit(ret); + } + +close_conn: + close(conn_fd); + + return ret; +} + +int connect_to_host(const char *host, const char *port) +{ + struct addrinfo *result, *it = NULL; + struct addrinfo hints; + int socket_fd, ret = 0; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + + ret = getaddrinfo(host, port, &hints, &result); + if (ret) { + gai_print_errno(ret); + return -1; + } + + for (it = result; it; it = it->ai_next) { + socket_fd = socket(it->ai_family, it->ai_socktype, it->ai_protocol); + if (socket_fd < 0) { + print_errno("socket"); + continue; + } + + if (connect(socket_fd, it->ai_addr, it->ai_addrlen) < 0) { + print_errno("connect"); + goto close_socket; + } + + break; + + close_socket: + close(socket_fd); + } + + freeaddrinfo(result); + + if (!it) { + print_error("Couldn't connect to host %s, port %s\n", host, port); + return -1; + } + + return socket_fd; +} + +int send_all(int fd, const void *buf, size_t len) +{ + size_t sent_total = 0; + + while (sent_total < len) { + ssize_t sent_now = write(fd, (const char *)buf + sent_total, len - sent_total); + + if (sent_now < 0) { + print_errno("write"); + return -1; + } + + sent_total += sent_now; + } + + return 0; +} + +int recv_all(int fd, void *buf, size_t len) +{ + size_t read_total = 0; + + while (read_total < len) { + ssize_t read_now = read(fd, buf, len); + + if (read_now < 0) { + print_errno("read"); + return -1; + } + + read_total += read_now; + } + + return read_total; +} + +int send_buf(int fd, const void *buf, size_t len) +{ + int ret = 0; + + ret = send_all(fd, &len, sizeof(len)); + if (ret < 0) + return ret; + + ret = send_all(fd, buf, len); + if (ret < 0) + return ret; + + return ret; +} + +int recv_buf(int fd, void **buf, size_t *len) +{ + int ret = 0; + + ret = recv_all(fd, len, sizeof(*len)); + if (ret < 0) + return ret; + + *buf = malloc(*len); + if (!*buf) { + print_errno("malloc"); + return -1; + } + + ret = recv_all(fd, *buf, *len); + if (ret < 0) + goto free_buf; + + return ret; + +free_buf: + free(*buf); + + return ret; +} + +int recv_static(int fd, void *buf, size_t len) +{ + void *actual_buf; + size_t actual_len; + int ret = 0; + + ret = recv_buf(fd, &actual_buf, &actual_len); + if (ret < 0) + return ret; + + if (actual_len != len) { + print_error("Expected message length: %lu, actual: %lu\n", len, actual_len); + ret = -1; + goto free_buf; + } + + memcpy(buf, actual_buf, len); + +free_buf: + free(actual_buf); + + return ret; +} |