这是连续剧般的文章,请关注,持续更新中...
系列文章:
这篇文章将我们的reactro转变成http服务器...
HTTP
HTTP介绍
HTTP是一个基于TCP通信协议的基础上的应用层协议。接下来我们需要解析HTTP请求消息、根据业务对数据进行处理、封装HTTP响应消息发出去。
HTTP请求消息格式
客户端发送一个 HTTP 请求到服务器的请求消息包括以下格式:请求行(request line)、请求头部(header)、空行和请求数据四个部分组成,下图给出了请求报文的一般格式。
HTTP响应消息格式
HTTP 响应由四个部分组成,分别是:状态行、消息报头、空行和响应正文。
HTTP业务流程
HTTP请求消息格式里面的URL就是客户端要想的资源,例如这里就是index.html。所以我们需要从浏览器发来的请求中,把url解析出来,这是第一步;解析出来请求的资源后我们需要去查找服务器是否存在该资源,如果有则状态200,如果没有则404Not Found,这是第二步;我们观察到有个Accpet字段,这是浏览器想要获得资源的类型,所以我们响应发回的响应消息里面,要根据请求的资源,填充Content-Type字段,这是第三步;还有一个需要注意的点,Content-Length字段是根据响应正文(请求的资源)的大小来计算的,我们需要计算资源大小并填充Content-Length字段,这是第四步。至此,响应头就组装好了,后面再按照格式加个换行,最后再把资源发过去就行了。
代码补充
recv_cb修改
int readline(char *allbuf, int idx, char *linebuf) { uint len = strlen(allbuf); for (; idx < len; idx++) { if (allbuf[idx] == '\r' && allbuf[idx + 1] == '\n') { return idx + 2; } else { *(linebuf++) = allbuf[idx]; } } return -1; } int http_request(struct ntyevent *ev) { char line_buffer[1024] = {0}; readline(ev->buffer, 0, line_buffer); if (strstr(line_buffer, "GET")) { ev->method = HTTP_METHOD_GET; //uri int i = 0; while (line_buffer[sizeof("GET ") + i] != ' ') i++; line_buffer[sizeof("GET ") + i] = '\0'; sprintf(ev->resource, "./%s/%s", HTTP_WEBSERVER_HTML_ROOT, line_buffer + sizeof("GET ")); //Content-Type if (strstr(line_buffer + sizeof("GET "), ".")) { char *type = strchr(line_buffer + sizeof("GET "), '.') + 1; if (strcmp(type, "html") == 0 || strcmp(type, "css") == 0) { sprintf(ev->Content_Type, "text/%s", type); } else if (strcmp(type, "jpg") == 0 || strcmp(type, "png") == 0 || strcmp(type, "ico") == 0) { sprintf(ev->Content_Type, "image/%s", type); } } else { sprintf(ev->Content_Type, "text/html"); } } } int recv_cb(int fd, int events, void *arg) { struct ntyreactor *reactor = (struct ntyreactor *) arg; struct ntyevent *ev = ntyreactor_find_event_idx(reactor, fd); int len = recv(fd, ev->buffer, BUFFER_LENGTH, 0); // nty_event_del(reactor->epfd, ev); if (len > 0) { ev->length = len; ev->buffer[len] = '\0'; printf("[socket fd=%d recv]\n%s\n", fd, ev->buffer); //http http_request(ev); nty_event_set(ev, fd, send_cb, reactor); nty_event_add(reactor->epfd, EPOLLOUT, ev); } else if (len == 0) { close(ev->fd); } else { close(ev->fd); } return len; }
send_cb修改
int http_response(struct ntyevent *ev) { if (ev == NULL) return -1; memset(ev->buffer, 0, BUFFER_LENGTH); int filefd = open(ev->resource, O_RDONLY); if (filefd == -1) { // return 404 ev->ret_code = 404; ev->length = sprintf(ev->buffer, "HTTP/1.1 404 Not Found\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: 83\r\n\r\n" "<html><head><title>404 Not Found</title></head><body><H1>404</H1></body></html>\r\n\r\n", ev->Content_Type); } else { struct stat stat_buf; fstat(filefd, &stat_buf); close(filefd); if (S_ISDIR(stat_buf.st_mode)) { ev->ret_code = 404; ev->length = sprintf(ev->buffer, "HTTP/1.1 404 Not Found\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: 83\r\n\r\n" "<html><head><title>404 Not Found</title></head><body><H1>404</H1></body></html>\r\n\r\n", ev->Content_Type); } else if (S_ISREG(stat_buf.st_mode)) { ev->ret_code = 200; ev->length = sprintf(ev->buffer, "HTTP/1.1 200 OK\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: %ld\r\n\r\n", ev->Content_Type, stat_buf.st_size); } } return ev->length; } int send_cb(int fd, int events, void *arg) { struct ntyreactor *reactor = (struct ntyreactor *) arg; struct ntyevent *ev = ntyreactor_find_event_idx(reactor, fd); http_response(ev); printf("[socket fd=%d count=%d]\n%s", fd, ev->length, ev->buffer); int res_head_len = send(fd, ev->buffer, ev->length, 0); if (res_head_len > 0) { if (ev->ret_code == 200) { int filefd = open(ev->resource, O_RDONLY); struct stat stat_buf; fstat(filefd, &stat_buf); off_t offset = 0; while (offset != stat_buf.st_size) { int n = sendfile(fd, filefd, &offset, (stat_buf.st_size - offset)); if (n == -1 && errno == EAGAIN) { usleep(5000); continue; } } printf("[resource: %s count:%ld]\r\n", ev->resource, offset); close(filefd); } nty_event_del(reactor->epfd, ev); nty_event_set(ev, fd, recv_cb, reactor); nty_event_add(reactor->epfd, EPOLLIN, ev); } else { nty_event_del(reactor->epfd, ev); close(ev->fd); } return 0; }
sendfile
有时候我们发送的资源可能是图片、文本等,所以我们需要提供这样的方法。
int filefd = open(ev->resource, O_RDONLY); struct stat stat_buf; fstat(filefd, &stat_buf); off_t offset = 0; while (offset != stat_buf.st_size) { int n = sendfile(fd, filefd, &offset, (stat_buf.st_size - offset)); if (n == -1 && errno == EAGAIN) { usleep(5000); continue; } } printf("[resource: %s count:%ld]\r\n", ev->resource, offset); close(filefd);
完整代码
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/socket.h> #include <sys/epoll.h> #include <arpa/inet.h> #include <fcntl.h> #include <unistd.h> #include <errno.h> #include <sys/stat.h> #include <sys/sendfile.h> #define BUFFER_LENGTH 4096 #define MAX_EPOLL_EVENTS 1024 #define SERVER_PORT 8080 #define PORT_COUNT 100 #define HTTP_METHOD_GET 0 #define HTTP_METHOD_POST 1 #define HTTP_WEBSERVER_HTML_ROOT "html" typedef int (*NCALLBACK)(int, int, void *); struct ntyevent { int fd; int events; void *arg; NCALLBACK callback; int status; char buffer[BUFFER_LENGTH]; int length; //http param int method; // char resource[BUFFER_LENGTH]; int ret_code; char Content_Type[512]; }; struct eventblock { struct eventblock *next; struct ntyevent *events; }; struct ntyreactor { int epfd; int blkcnt; struct eventblock *evblk; }; int recv_cb(int fd, int events, void *arg); int send_cb(int fd, int events, void *arg); struct ntyevent *ntyreactor_find_event_idx(struct ntyreactor *reactor, int sockfd); void nty_event_set(struct ntyevent *ev, int fd, NCALLBACK callback, void *arg) { ev->fd = fd; ev->callback = callback; ev->events = 0; ev->arg = arg; } int nty_event_add(int epfd, int events, struct ntyevent *ev) { struct epoll_event ep_ev = {0, {0}}; ep_ev.data.ptr = ev; ep_ev.events = ev->events = events; int op; if (ev->status == 1) { op = EPOLL_CTL_MOD; } else { op = EPOLL_CTL_ADD; ev->status = 1; } if (epoll_ctl(epfd, op, ev->fd, &ep_ev) < 0) { printf("event add failed [fd=%d], events[%d]\n", ev->fd, events); return -1; } return 0; } int nty_event_del(int epfd, struct ntyevent *ev) { struct epoll_event ep_ev = {0, {0}}; if (ev->status != 1) { return -1; } ep_ev.data.ptr = ev; ev->status = 0; epoll_ctl(epfd, EPOLL_CTL_DEL, ev->fd, &ep_ev); return 0; } int readline(char *allbuf, int idx, char *linebuf) { uint len = strlen(allbuf); for (; idx < len; idx++) { if (allbuf[idx] == '\r' && allbuf[idx + 1] == '\n') { return idx + 2; } else { *(linebuf++) = allbuf[idx]; } } return -1; } int http_request(struct ntyevent *ev) { char line_buffer[1024] = {0}; readline(ev->buffer, 0, line_buffer); if (strstr(line_buffer, "GET")) { ev->method = HTTP_METHOD_GET; //uri int i = 0; while (line_buffer[sizeof("GET ") + i] != ' ') i++; line_buffer[sizeof("GET ") + i] = '\0'; sprintf(ev->resource, "./%s/%s", HTTP_WEBSERVER_HTML_ROOT, line_buffer + sizeof("GET ")); //Content-Type if (strstr(line_buffer + sizeof("GET "), ".")) { char *type = strchr(line_buffer + sizeof("GET "), '.') + 1; if (strcmp(type, "html") == 0 || strcmp(type, "css") == 0) { sprintf(ev->Content_Type, "text/%s", type); } else if (strcmp(type, "jpg") == 0 || strcmp(type, "png") == 0 || strcmp(type, "ico") == 0) { sprintf(ev->Content_Type, "image/%s", type); } } else { sprintf(ev->Content_Type, "text/html"); } } } int recv_cb(int fd, int events, void *arg) { struct ntyreactor *reactor = (struct ntyreactor *) arg; struct ntyevent *ev = ntyreactor_find_event_idx(reactor, fd); int len = recv(fd, ev->buffer, BUFFER_LENGTH, 0); // nty_event_del(reactor->epfd, ev); if (len > 0) { ev->length = len; ev->buffer[len] = '\0'; printf("[socket fd=%d recv]\n%s\n", fd, ev->buffer); //http http_request(ev); nty_event_set(ev, fd, send_cb, reactor); nty_event_add(reactor->epfd, EPOLLOUT, ev); } else if (len == 0) { close(ev->fd); } else { close(ev->fd); } return len; } int http_response(struct ntyevent *ev) { if (ev == NULL) return -1; memset(ev->buffer, 0, BUFFER_LENGTH); int filefd = open(ev->resource, O_RDONLY); if (filefd == -1) { // return 404 ev->ret_code = 404; ev->length = sprintf(ev->buffer, "HTTP/1.1 404 Not Found\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: 83\r\n\r\n" "<html><head><title>404 Not Found</title></head><body><H1>404</H1></body></html>\r\n\r\n", ev->Content_Type); } else { struct stat stat_buf; fstat(filefd, &stat_buf); close(filefd); if (S_ISDIR(stat_buf.st_mode)) { ev->ret_code = 404; ev->length = sprintf(ev->buffer, "HTTP/1.1 404 Not Found\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: 83\r\n\r\n" "<html><head><title>404 Not Found</title></head><body><H1>404</H1></body></html>\r\n\r\n", ev->Content_Type); } else if (S_ISREG(stat_buf.st_mode)) { ev->ret_code = 200; ev->length = sprintf(ev->buffer, "HTTP/1.1 200 OK\r\n" "Content-Type: %s;charset=utf-8\r\n" "Content-Length: %ld\r\n\r\n", ev->Content_Type, stat_buf.st_size); } } return ev->length; } int send_cb(int fd, int events, void *arg) { struct ntyreactor *reactor = (struct ntyreactor *) arg; struct ntyevent *ev = ntyreactor_find_event_idx(reactor, fd); http_response(ev); printf("[socket fd=%d count=%d]\n%s", fd, ev->length, ev->buffer); int res_head_len = send(fd, ev->buffer, ev->length, 0); if (res_head_len > 0) { if (ev->ret_code == 200) { int filefd = open(ev->resource, O_RDONLY); struct stat stat_buf; fstat(filefd, &stat_buf); off_t offset = 0; while (offset != stat_buf.st_size) { int n = sendfile(fd, filefd, &offset, (stat_buf.st_size - offset)); if (n == -1 && errno == EAGAIN) { usleep(5000); continue; } } printf("[resource: %s count:%ld]\r\n", ev->resource, offset); close(filefd); } nty_event_del(reactor->epfd, ev); nty_event_set(ev, fd, recv_cb, reactor); nty_event_add(reactor->epfd, EPOLLIN, ev); } else { nty_event_del(reactor->epfd, ev); close(ev->fd); } return 0; } int accept_cb(int fd, int events, void *arg) {//非阻塞 struct ntyreactor *reactor = (struct ntyreactor *) arg; if (reactor == NULL) return -1; struct sockaddr_in client_addr; socklen_t len = sizeof(client_addr); int clientfd; if ((clientfd = accept(fd, (struct sockaddr *) &client_addr, &len)) == -1) { printf("accept: %s\n", strerror(errno)); return -1; } if ((fcntl(clientfd, F_SETFL, O_NONBLOCK)) < 0) { printf("%s: fcntl nonblocking failed, %d\n", __func__, MAX_EPOLL_EVENTS); return -1; } struct ntyevent *event = ntyreactor_find_event_idx(reactor, clientfd); nty_event_set(event, clientfd, recv_cb, reactor); nty_event_add(reactor->epfd, EPOLLIN, event); printf("new connect [%s:%d], pos[%d]\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), clientfd); return 0; } int init_sock(short port) { int fd = socket(AF_INET, SOCK_STREAM, 0); fcntl(fd, F_SETFL, O_NONBLOCK); struct sockaddr_in server_addr; memset(&server_addr, 0, sizeof(server_addr)); server_addr.sin_family = AF_INET; server_addr.sin_addr.s_addr = htonl(INADDR_ANY); server_addr.sin_port = htons(port); bind(fd, (struct sockaddr *) &server_addr, sizeof(server_addr)); if (listen(fd, 20) < 0) { printf("listen failed : %s\n", strerror(errno)); } return fd; } int ntyreactor_alloc(struct ntyreactor *reactor) { if (reactor == NULL) return -1; if (reactor->evblk == NULL) return -1; struct eventblock *blk = reactor->evblk; while (blk->next != NULL) { blk = blk->next; } struct ntyevent *evs = (struct ntyevent *) malloc((MAX_EPOLL_EVENTS) * sizeof(struct ntyevent)); if (evs == NULL) { printf("ntyreactor_alloc ntyevents failed\n"); return -2; } memset(evs, 0, (MAX_EPOLL_EVENTS) * sizeof(struct ntyevent)); struct eventblock *block = (struct eventblock *) malloc(sizeof(struct eventblock)); if (block == NULL) { printf("ntyreactor_alloc eventblock failed\n"); return -2; } memset(block, 0, sizeof(struct eventblock)); block->events = evs; block->next = NULL; blk->next = block; reactor->blkcnt++; // return 0; } struct ntyevent *ntyreactor_find_event_idx(struct ntyreactor *reactor, int sockfd) { int blkidx = sockfd / MAX_EPOLL_EVENTS; while (blkidx >= reactor->blkcnt) { ntyreactor_alloc(reactor); } int i = 0; struct eventblock *blk = reactor->evblk; while (i++ < blkidx && blk != NULL) { blk = blk->next; } return &blk->events[sockfd % MAX_EPOLL_EVENTS]; } int ntyreactor_init(struct ntyreactor *reactor) { if (reactor == NULL) return -1; memset(reactor, 0, sizeof(struct ntyreactor)); reactor->epfd = epoll_create(1); if (reactor->epfd <= 0) { printf("create epfd in %s err %s\n", __func__, strerror(errno)); return -2; } struct ntyevent *evs = (struct ntyevent *) malloc((MAX_EPOLL_EVENTS) * sizeof(struct ntyevent)); if (evs == NULL) { printf("ntyreactor_alloc ntyevents failed\n"); return -2; } memset(evs, 0, (MAX_EPOLL_EVENTS) * sizeof(struct ntyevent)); struct eventblock *block = (struct eventblock *) malloc(sizeof(struct eventblock)); if (block == NULL) { printf("ntyreactor_alloc eventblock failed\n"); return -2; } memset(block, 0, sizeof(struct eventblock)); block->events = evs; block->next = NULL; reactor->evblk = block; reactor->blkcnt = 1; return 0; } int ntyreactor_destory(struct ntyreactor *reactor) { close(reactor->epfd); //free(reactor->events); struct eventblock *blk = reactor->evblk; struct eventblock *blk_next = NULL; while (blk != NULL) { blk_next = blk->next; free(blk->events); free(blk); blk = blk_next; } return 0; } int ntyreactor_addlistener(struct ntyreactor *reactor, int sockfd, NCALLBACK acceptor) { if (reactor == NULL) return -1; if (reactor->evblk == NULL) return -1; struct ntyevent *event = ntyreactor_find_event_idx(reactor, sockfd); nty_event_set(event, sockfd, acceptor, reactor); nty_event_add(reactor->epfd, EPOLLIN, event); return 0; } int ntyreactor_run(struct ntyreactor *reactor) { if (reactor == NULL) return -1; if (reactor->epfd < 0) return -1; if (reactor->evblk == NULL) return -1; struct epoll_event events[MAX_EPOLL_EVENTS + 1]; int i; while (1) { int nready = epoll_wait(reactor->epfd, events, MAX_EPOLL_EVENTS, 1000); if (nready < 0) { printf("epoll_wait error, exit\n"); continue; } for (i = 0; i < nready; i++) { struct ntyevent *ev = (struct ntyevent *) events[i].data.ptr; if ((events[i].events & EPOLLIN) && (ev->events & EPOLLIN)) { ev->callback(ev->fd, events[i].events, ev->arg); } if ((events[i].events & EPOLLOUT) && (ev->events & EPOLLOUT)) { ev->callback(ev->fd, events[i].events, ev->arg); } } } return 0; } int main(int argc, char *argv[]) { unsigned short port = SERVER_PORT; if (argc == 2) { port = atoi(argv[1]); } struct ntyreactor *reactor = (struct ntyreactor *) malloc(sizeof(struct ntyreactor)); ntyreactor_init(reactor); int i; int sockfds[PORT_COUNT] = {0}; for (i = 0; i < PORT_COUNT; i++) { sockfds[i] = init_sock(port + i); ntyreactor_addlistener(reactor, sockfds[i], accept_cb); } ntyreactor_run(reactor); ntyreactor_destory(reactor); for (i = 0; i < PORT_COUNT; i++) { close(sockfds[i]); } free(reactor); return 0; }