summaryrefslogtreecommitdiffstats
path: root/hw1/proc_r.c
blob: 19dce78047f404bd10dfc25049b954d996aed680 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
#include "common.h"
#include "proc.h"

#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

bool procconn(server* svr, request* req, int maxfd){
    fd_set rset = svr->readfds;
    fd_set wset = svr->writefds;
    fd_set eset = svr->exceptfds;
    struct timeval timeout = { 1, 0 };
    int rval;

    if (select (maxfd, &rset, &wset, &eset, &timeout) < 0) {
        perror ("select");
        return true;
    }

    for (int i = 0; i < maxfd; i++) {
        if (!FD_ISSET (i, &rset))
            continue;

        if (i == svr->listen_fd) {
            struct sockaddr_in client_addr;
            int client_len;
            int conn_fd = accept (i,
                (struct sockaddr*)&client_addr, (socklen_t*)&client_len);
            if (conn_fd < 0) {
                switch (errno) {
                    case EINTR:
                    case EAGAIN:
                        continue;
                    case EMFILE:
                    case ENFILE:
                        fprintf (stderr, "Too many open file ... "
                            "(maxconn %d)\n", maxfd);
                        continue;
                    default:
                        perror ("accept");
                        continue;
                }
            } else {
                req[conn_fd].conn_fd = conn_fd;
                req[conn_fd].active = true;
                strcpy(req[conn_fd].host, inet_ntoa(client_addr.sin_addr));
                fprintf(stderr, "Accept a new request: fd %d from %s\n",
                    conn_fd, req[conn_fd].host);
                FD_SET (conn_fd, &(svr->readfds));
            }
        } else {
            rval = request_read(&req[i]);
            if (rval <= 0) {
                fprintf (stderr, "fd %d from %s: %s%s\n",
                    i, req[i].host,
                    rval < 0 ? "socket error: " : "command done",
                    rval < 0 ? strerror (errno) : "");
                request_free (&req[i], svr);
            } else {
                if (req[i].header_done) {
                    FD_CLR (req[i].conn_fd, &(svr->readfds));
                    FD_SET (req[i].conn_fd, &(svr->writefds));
                }
            }
        }
    }

    for (int i = 0; i < maxfd; i++) {
        if (!FD_ISSET (i, &wset))
            continue;
        if (i == svr->listen_fd)
            continue;

        if (req[i].header_done) {
            if (!req[i].header_accept) {
                req[i].file_fd = open (req[i].filename, O_RDONLY);
                fprintf (stderr, "fd %d from %s: open %s %s%s\n",
                    i, req[i].host, req[i].filename,
                    req[i].file_fd < 0 ? "error: " : "done",
                    req[i].file_fd < 0 ? strerror(errno) : "");
                if (req[i].file_fd < 0) {
                    write (req[i].conn_fd, svr->reject_hdr, SVR_REJECT_HDR_LEN);
                    request_free (&req[i], svr);
                    continue;
                }

                struct stat file_stat;
                rval = fstat (req[i].file_fd, &file_stat);
                fprintf (stderr, "fd %d from %s: fstat %s %s%s\n",
                    i, req[i].host, req[i].filename,
                    req[i].file_fd < 0 ? "error: " : "done",
                    req[i].file_fd < 0 ? strerror(errno) : "");
                if (req[i].file_fd < 0) {
                    write (req[i].conn_fd, svr->reject_hdr, SVR_REJECT_HDR_LEN);
                    request_free (&req[i], svr);
                    continue;
                }
                req[i].file_info = ftab_insert (
                    svr->file_table,
                    file_stat.st_dev,
                    file_stat.st_ino,
                    req[i].file_fd);

                struct flock lock_info = {
                    .l_type = F_RDLCK,
                    .l_whence = SEEK_SET,
                    .l_start = 0,
                    .l_len = 0
                };
                rval = fcntl (req[i].file_fd, F_SETLK, &lock_info);
                fprintf (stderr, "fd %d from %s: lock %s %s%s\n",
                    i, req[i].host, req[i].filename,
                    rval < 0 ? "error: " : "done",
                    rval < 0 ? strerror(errno) : "");
                if (rval < 0) {
                    write (req[i].conn_fd, svr->reject_hdr, SVR_REJECT_HDR_LEN);
                    request_free (&req[i], svr);
                    continue;
                }
                write (req[i].conn_fd, svr->accept_hdr, SVR_ACCEPT_HDR_LEN);
                req[i].header_accept = true;
            } else {
                if (!req[i].buf_len) {
                    rval = read (req[i].file_fd, req[i].buf, SVR_BUFFER_SIZE);
                    if (rval < 0) {
                        if (errno != EINTR &&
                            errno != EAGAIN)
                        {
                            // fatal error, close the connection
                            perror ("read");
                            request_free (&req[i], svr);
                        }
                        continue;
                    } else if (rval == 0) {
                        fprintf (stderr, "%d done\n", req[i].conn_fd);
                        request_free (&req[i], svr);
                        continue;
                    }

                    req[i].buf_set = 0;
                    req[i].buf_len = rval;
                }

                rval = write (req[i].conn_fd, req[i].buf + req[i].buf_set,
                    req[i].buf_len);
                if (rval < 0) {
                    perror("write");
                    request_free (&req[i], svr);
                    continue;
                }
                req[i].buf_set += rval;
                req[i].buf_len -= rval;
            }
        }
    }

    return true;
}