利用libuv库和smtp协议发送邮件程序

我写这个程序只是练习利用libuv库写程序，怎样连接服务器，怎样处理读写。

这只是一个demo，离真正的发送邮件程序还有一些距离。

附上源代码：

#include <uv.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>

#define FATAL(msg)                                        \
  do {                                                    \
    fprintf(stderr,                                       \
            "Fatal error in %s on line %d: %s\n",         \
            __FILE__,                                     \
            __LINE__,                                     \
            msg);                                         \
    fflush(stderr);                                       \
    abort();                                              \
  } while (0)


typedef struct smtp_s {
	char *helo;
	char *from;
	char *rcpt_to;
	char *data;  
	char *subject;
} smtp_t;

typedef enum {
	START = 0,
	HELO,
	FROM,
	RCPT_TO,
	DATA,
	SUBJECT,
	MAX_STATE
} smtp_states;
	
static char *smtp_code[] = {
	"220",
	"250",
	"250",
	"250",
	"354",
	"250"
};

static char *smtp_name[] = {
	"start",
	"helo",
	"from",
	"rcpt_to",
	"data",
	"subject"
};

static char *smtp_msg[] = {
	"helo vrm\r\n",
	"mail from:<engine@vrm.com\r\n",
	"rcpt to:<1348104823@qq.com>\r\n",  // 改成你自己的QQ邮箱帐号
	"data\r\n",
	"this is a test\r\n.\r\n"
};

static smtp_t smtp;
static smtp_states state = START;
static uv_loop_t *loop;


static void connect_cb(uv_connect_t *req, int status);
static void read_server_cb(uv_stream_t *stream, ssize_t nread, uv_buf_t buf);
static void write_server_cb(uv_write_t *req, int status);
static uv_buf_t alloc_cb(uv_handle_t *handle, size_t suggested_size);


static void connect_cb(uv_connect_t *req, int status)
{
	int r;
	
	uv_read_start(req->handle, alloc_cb, read_server_cb);
}


static uv_buf_t alloc_cb(uv_handle_t *handle, size_t suggested_size)
{
	return uv_buf_init(malloc(suggested_size), suggested_size);
}

static void write_server_cb(uv_write_t *req, int status)
{
	uv_err_t err;
	free(req);
	state += 1;
	if (status == 0) {
		return;
	}
	
	err = uv_last_error(loop);
	fprintf(stderr, "uv_write error: %s\n", uv_strerror(err));
	if (err.code == UV_ECANCELED) {
		return;
	}

	
}

static void read_server_cb(uv_stream_t *stream, ssize_t nread, uv_buf_t buf)
{
	uv_write_t *wr;
	size_t len;
	int flag = 0;
	if (state == MAX_STATE) {
		uv_close((uv_handle_t *) stream, NULL);
		printf("smtp end\r\n");
		return;
	}
	if (strncmp(smtp_code[state], buf.base, 3) != 0) {
		uv_close((uv_handle_t *) stream, NULL);
		fprintf(stderr, "stmp state %s error: %s\n",
			smtp_name[state],
			buf.base);
		return;
	}


	free(buf.base);
	wr = (uv_write_t *) malloc(sizeof(uv_write_t));

	len = strlen(smtp_msg[state]);
	buf = uv_buf_init(smtp_msg[state], len);

	if (uv_write(wr, stream, &buf, 1, write_server_cb)) {
		FATAL("uv_write failed");
	}
	
}

int main()
{
	uv_tcp_t tcp;
	uv_connect_t req;
	struct sockaddr_in client_addr, server_addr;
	int r;
	loop = uv_default_loop();
	
	client_addr = uv_ip4_addr("0.0.0.0", 0);
	server_addr = uv_ip4_addr("119.147.192.101", 25);

	r = uv_tcp_init(loop, &tcp);
	assert(!r);

	uv_tcp_bind(&tcp, client_addr);
	r = uv_tcp_connect(&req, &tcp, server_addr, connect_cb);
	assert(!r);

	uv_run(loop, UV_RUN_DEFAULT);

	return 0;
}