shttpd_request.c

#include "shttpd.h"

extern void Error_400(struct worker_ctl *wctl);

extern void Error_403(struct worker_ctl *wctl);

extern void Error_404(struct worker_ctl *wctl);

extern void Error_505(struct worker_ctl *wctl);

static struct http_header http_headers[] = {
        {16, HDR_INT,    OFFSET(cl),         "Content-Length: "},
        {14, HDR_STRING, OFFSET(ct),         "Content-Type: "},
        {12, HDR_STRING, OFFSET(useragent),  "User-Agent: "},
        {19, HDR_DATE,   OFFSET(ims),        "If-Modified-Since: "},
        {15, HDR_STRING, OFFSET(auth),       "Authorization: "},
        {9,  HDR_STRING, OFFSET(referer),    "Referer: "},
        {8,  HDR_STRING, OFFSET(cookie),     "Cookie: "},
        {10, HDR_STRING, OFFSET(location),   "Location: "},
        {8,  HDR_INT,    OFFSET(status),     "Status: "},
        {7,  HDR_STRING, OFFSET(range),      "Range: "},
        {12, HDR_STRING, OFFSET(connection), "Connection: "},
        {19, HDR_STRING, OFFSET(transenc),   "Transfer-Encoding: "},
        {0,  HDR_INT, 0, NULL}
};
extern struct vec _shttpd_methods[];
struct conf_opts conf_para;

/*
 * Convert month to the month number. Return -1 on error, or month number
 */
static int
montoi(char *s) {
    DBGPRINT("==>montoi\n");
    int retval = -1;
    static char *ar[] = {
            "Jan", "Feb", "Mar", "Apr", "May", "Jun",
            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
    };
    size_t i;

    for (i = 0; i < sizeof(ar) / sizeof(ar[0]); i++)
        if (!strcmp(s, ar[i])) {
            retval = i;
            goto EXITmontoi;
        }
    DBGPRINT("<==montoi\n");
    EXITmontoi:
    return retval;
}

/*
 * Parse date-time string, and return the corresponding time_t value
 */
static time_t
date_to_epoch(char *s) {
    DBGPRINT("==>date_to_epoch\n");
    struct tm tm;
    char mon[32];
    int sec, min, hour, mday, month, year;

    (void) memset(&tm, 0, sizeof(tm));
    sec = min = hour = mday = month = year = 0;

    if (((sscanf(s, "%d/%3s/%d %d:%d:%d",
                 &mday, mon, &year, &hour, &min, &sec) == 6) ||
         (sscanf(s, "%d %3s %d %d:%d:%d",
                 &mday, mon, &year, &hour, &min, &sec) == 6) ||
         (sscanf(s, "%*3s, %d %3s %d %d:%d:%d",
                 &mday, mon, &year, &hour, &min, &sec) == 6) ||
         (sscanf(s, "%d-%3s-%d %d:%d:%d",
                 &mday, mon, &year, &hour, &min, &sec) == 6)) &&
        (month = montoi(mon)) != -1) {
        tm.tm_mday = mday;
        tm.tm_mon = month;
        tm.tm_year = year;
        tm.tm_hour = hour;
        tm.tm_min = min;
        tm.tm_sec = sec;
    }

    if (tm.tm_year > 1900)
        tm.tm_year -= 1900;
    else if (tm.tm_year < 70)
        tm.tm_year += 100;

    DBGPRINT("<==date_to_epoch\n");
    return (mktime(&tm));
}

void Request_HeaderParse(char *s, int len, struct headers *parsed) {
    DBGPRINT("==>Request_HeaderParse\n");
    struct http_header *h;    /*结构struct http_header指针*/
    union variant *v;/*通用参数*/
    char *p, *e = s + len;/*p当前位置,e尾部*/


    /* 查找请求字符串中的头部关键字*/
    while (s < e) {

        /* 查找一行末尾*/
        for (p = s; p < e && *p != '\n';) {
            p++;
        }

        /* 已知方法*/
        for (h = http_headers; h->len != 0; h++) {
            if (e - s > h->len &&    /*字符串匹配*/
                !strncasecmp(s, h->name, h->len)) {
                break;
            }
        }

        /* 将此方法放入*/
        if (h->len != 0) {

            /* 请求字符串中值的位置*/
            s += h->len;

            /* 将值存放到参数parsed中 */
            v = (union variant *) ((char *) parsed + h->offset);

            /* 根据头部选项不同,计算不同的值*/
            if (h->type == HDR_STRING) /*字符串类型*/
            {
                v->v_vec.ptr = s;/*字符串开始*/
                v->v_vec.len = p - s;/*字符串长度*/
                if (p[-1] == '\r' && v->v_vec.len > 0) {
                    v->v_vec.len--;
                }
            }
            else if (h->type == HDR_INT) /*INT类型*/
            {
                v->v_big_int = strtoul(s, NULL, 10);
            }
            else if (h->type == HDR_DATE) /*时间格式*/
            {
                v->v_time = date_to_epoch(s);
            }
        }

        s = p + 1;    /* Shift to the next header */
    }

    DBGPRINT("<==Request_HeaderParse\n");
}

#define JUMPOVER_CHAR(p, over) do{for(;*p== over;p++);}while(0);
#define JUMPTO_CHAR(p, to) do{for(;*p!= to;p++);}while(0);

/* 分析获得的请求 */
int Request_Parse(struct worker_ctl *wctl) {
    DBGPRINT("==>Request_Parse\n");
    struct worker_conn *c = &wctl->conn;
    struct conn_request *req = &c->con_req;
    struct conn_response *res = &c->con_res;
    int retval = 200;

    char *p = req->req.ptr;
    int len = req->req.len;
    char *pos = NULL;

    /*处理第一行*/
    /*[GET /root/default.html HTTP/1.1\r\n]*/
    /*查找一行末尾*/
    pos = memchr(p, '\n', len);
    if (*(pos - 1) == '\r') {
        *(pos - 1) = '\0';
    }
    *pos = '\0';

    pos = p;

    /***********************方法*********************/
    int found = 0;

    JUMPOVER_CHAR(pos, ' ');/*跳过空格*/
    ;
    struct vec *m = NULL;
    /*查找比较方法字符串*/
    for (m = &_shttpd_methods[0]; m->ptr != NULL; m++) {
        if (!strncmp(m->ptr, pos, m->len))/*比较字符串*/
        {
            req->method = m->type;/*更新头部方法*/
            found = 1;
            break;
        }
    }
    if (!found) {
        retval = 400;
        goto EXITRequest_Parse;
    }

    /*URI分析*/
    pos += m->len;/*跳过方法*/
    JUMPOVER_CHAR(pos, ' ');/*跳过空格*/

    len -= pos - p;
    p = pos;
    JUMPTO_CHAR(pos, ' ');/*跳到空格*/
    *pos = '\0';

    req->uri = (char *) p;
    /*文件*/
    snprintf(req->rpath, URI_MAX, "%s/%s", conf_para.DocumentRoot, req->uri);
    res->fd = open(req->rpath, O_RDONLY, 0644);
    if (res->fd != -1) {
        fstat(res->fd, &res->fsate);
        if (S_ISDIR(res->fsate.st_mode)) {
            retval = 403;
            goto EXITRequest_Parse;
        }
    }
    else {

        retval = 404;
        goto EXITRequest_Parse;
    }

    /*HTTP版本:
    *	HTTP/[1|0].[1|0|9]
    */
    pos += 1;
    JUMPOVER_CHAR(pos, ' ');/*跳过空格*/

    len -= pos - p;
    p = pos;
    sscanf(p,
           "HTTP/%lu.%lu",
           &req->major,
           &req->minor);
    if (!((req->major == 0 && req->minor == 9) ||
          (req->major == 1 && req->minor == 0) ||
          (req->major == 1 && req->minor == 1))) {
        retval = 505;
        goto EXITRequest_Parse;
    }


    /*其他头部信息*/
    JUMPTO_CHAR(pos, '\0');
    JUMPOVER_CHAR(pos, '\0');/*跳过空字符*/
    len -= pos - p;
    p = pos;
    Request_HeaderParse(p, len, &req->ch);
    DBGPRINT("URI:'%s',patch:'%s'\n", req->uri, req->rpath);
    EXITRequest_Parse:
    DBGPRINT("<==Request_Parse\n");
    return retval;
}


int Request_Handle(struct worker_ctl *wctl) {
    DBGPRINT("==>Request_Handle\n");
    int err = wctl->conn.con_req.err;
    int cs = wctl->conn.cs;
    int cl = -1;
    char *ptr = wctl->conn.con_res.res.ptr;
    int len = -1;
    int n = -1;

    switch (err) {
        case 200:
            Method_Do(wctl);
            int fd = wctl->conn.con_res.fd;
            cl = wctl->conn.con_res.cl;
            len = strlen(wctl->conn.con_res.res.ptr);

            n = write(cs, ptr, len);
            printf("echo header:%s, write to client %d bytes, status:%d\n", ptr, n, wctl->conn.con_res.status);

            if (fd != -1) {
                lseek(fd, 0, SEEK_SET);
                len = sizeof(wctl->conn.dres);
                printf("response len:%d, content length:%d\n", len, wctl->conn.con_res.cl);
                for (n = 0; cl > 0; cl -= n) {
                    n = read(fd, ptr, len > cl ? cl : sizeof(wctl->conn.dres));
                    printf("read %d bytes,", n);
                    if (n > 0) {
                        n = write(cs, ptr, n);
                        printf("write %d bytes\n", n);
                    }
                }
                close(fd);
                wctl->conn.con_res.fd = -1;
            }

            break;
        default:
        case 400:
            Error_400(wctl);
            cl = wctl->conn.con_res.cl;
            len = strlen(wctl->conn.con_res.res.ptr);

            n = write(cs, ptr, len);
            break;
        case 403:
            Error_403(wctl);
            cl = wctl->conn.con_res.cl;
            len = strlen(wctl->conn.con_res.res.ptr);

            n = write(cs, ptr, len);
            break;
        case 404:
            Error_404(wctl);
            cl = wctl->conn.con_res.cl;
            len = strlen(wctl->conn.con_res.res.ptr);

            n = write(cs, ptr, len);
            break;
        case 505:
            Error_505(wctl);
            cl = wctl->conn.con_res.cl;
            len = strlen(wctl->conn.con_res.res.ptr);

            n = write(cs, ptr, len);
            break;

    }
    DBGPRINT("<==Request_Handle\n");
    return 0;
}