view src/mail/ngx_mail_parse.c @ 4147:7f64de1cc2c0

Fix for double content when return is used in error_page handler. Test case: location / { error_page 405 /nope; return 405; } location /nope { return 200; } This is expected to return 405 with empty body, but in 0.8.42+ will return builtin 405 error page as well (though not counted in Content-Length, thus breaking protocol). Fix is to use status provided by rewrite script execution in case it's less than NGX_HTTP_BAD_REQUEST even if r->error_status set. This check is in line with one in ngx_http_script_return_code(). Note that this patch also changes behaviour for "return 302 ..." and "rewrite ... redirect" used as error handler. E.g. location / { error_page 405 /redirect; return 405; } location /redirect { rewrite ^ http://example.com/; } will actually return redirect to "http://example.com/" instead of builtin 405 error page with meaningless Location header. This looks like correct change and it's in line with what happens on e.g. directory redirects in error handlers.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 27 Sep 2011 11:11:30 +0000
parents a59b26eee816
children d620f497c50f
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_mail.h>


ngx_int_t
ngx_mail_pop3_parse_command(ngx_mail_session_t *s)
{
    u_char      ch, *p, *c, c0, c1, c2, c3;
    ngx_str_t  *arg;
    enum {
        sw_start = 0,
        sw_spaces_before_argument,
        sw_argument,
        sw_almost_done
    } state;

    state = s->state;

    for (p = s->buffer->pos; p < s->buffer->last; p++) {
        ch = *p;

        switch (state) {

        /* POP3 command */
        case sw_start:
            if (ch == ' ' || ch == CR || ch == LF) {
                c = s->buffer->start;

                if (p - c == 4) {

                    c0 = ngx_toupper(c[0]);
                    c1 = ngx_toupper(c[1]);
                    c2 = ngx_toupper(c[2]);
                    c3 = ngx_toupper(c[3]);

                    if (c0 == 'U' && c1 == 'S' && c2 == 'E' && c3 == 'R')
                    {
                        s->command = NGX_POP3_USER;

                    } else if (c0 == 'P' && c1 == 'A' && c2 == 'S' && c3 == 'S')
                    {
                        s->command = NGX_POP3_PASS;

                    } else if (c0 == 'A' && c1 == 'P' && c2 == 'O' && c3 == 'P')
                    {
                        s->command = NGX_POP3_APOP;

                    } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
                    {
                        s->command = NGX_POP3_QUIT;

                    } else if (c0 == 'C' && c1 == 'A' && c2 == 'P' && c3 == 'A')
                    {
                        s->command = NGX_POP3_CAPA;

                    } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
                    {
                        s->command = NGX_POP3_AUTH;

                    } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
                    {
                        s->command = NGX_POP3_NOOP;
#if (NGX_MAIL_SSL)
                    } else if (c0 == 'S' && c1 == 'T' && c2 == 'L' && c3 == 'S')
                    {
                        s->command = NGX_POP3_STLS;
#endif
                    } else {
                        goto invalid;
                    }

                } else {
                    goto invalid;
                }

                switch (ch) {
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;
            }

            if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                goto invalid;
            }

            break;

        case sw_spaces_before_argument:
            switch (ch) {
            case ' ':
                break;
            case CR:
                state = sw_almost_done;
                s->arg_end = p;
                break;
            case LF:
                s->arg_end = p;
                goto done;
            default:
                if (s->args.nelts <= 2) {
                    state = sw_argument;
                    s->arg_start = p;
                    break;
                }
                goto invalid;
            }
            break;

        case sw_argument:
            switch (ch) {

            case ' ':

                /*
                 * the space should be considered as part of the at username
                 * or password, but not of argument in other commands
                 */

                if (s->command == NGX_POP3_USER
                    || s->command == NGX_POP3_PASS)
                {
                    break;
                }

                /* fall through */

            case CR:
            case LF:
                arg = ngx_array_push(&s->args);
                if (arg == NULL) {
                    return NGX_ERROR;
                }
                arg->len = p - s->arg_start;
                arg->data = s->arg_start;
                s->arg_start = NULL;

                switch (ch) {
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;

            default:
                break;
            }
            break;

        case sw_almost_done:
            switch (ch) {
            case LF:
                goto done;
            default:
                goto invalid;
            }
        }
    }

    s->buffer->pos = p;
    s->state = state;

    return NGX_AGAIN;

done:

    s->buffer->pos = p + 1;

    if (s->arg_start) {
        arg = ngx_array_push(&s->args);
        if (arg == NULL) {
            return NGX_ERROR;
        }
        arg->len = s->arg_end - s->arg_start;
        arg->data = s->arg_start;
        s->arg_start = NULL;
    }

    s->state = (s->command != NGX_POP3_AUTH) ? sw_start : sw_argument;

    return NGX_OK;

invalid:

    s->state = sw_start;
    s->arg_start = NULL;

    return NGX_MAIL_PARSE_INVALID_COMMAND;
}


ngx_int_t
ngx_mail_imap_parse_command(ngx_mail_session_t *s)
{
    u_char      ch, *p, *c;
    ngx_str_t  *arg;
    enum {
        sw_start = 0,
        sw_spaces_before_command,
        sw_command,
        sw_spaces_before_argument,
        sw_argument,
        sw_backslash,
        sw_literal,
        sw_no_sync_literal_argument,
        sw_start_literal_argument,
        sw_literal_argument,
        sw_end_literal_argument,
        sw_almost_done
    } state;

    state = s->state;

    for (p = s->buffer->pos; p < s->buffer->last; p++) {
        ch = *p;

        switch (state) {

        /* IMAP tag */
        case sw_start:
            switch (ch) {
            case ' ':
                s->tag.len = p - s->buffer->start + 1;
                s->tag.data = s->buffer->start;
                state = sw_spaces_before_command;
                break;
            case CR:
                s->state = sw_start;
                return NGX_MAIL_PARSE_INVALID_COMMAND;
            case LF:
                s->state = sw_start;
                return NGX_MAIL_PARSE_INVALID_COMMAND;
            }
            break;

        case sw_spaces_before_command:
            switch (ch) {
            case ' ':
                break;
            case CR:
                s->state = sw_start;
                return NGX_MAIL_PARSE_INVALID_COMMAND;
            case LF:
                s->state = sw_start;
                return NGX_MAIL_PARSE_INVALID_COMMAND;
            default:
                s->cmd_start = p;
                state = sw_command;
                break;
            }
            break;

        case sw_command:
            if (ch == ' ' || ch == CR || ch == LF) {

                c = s->cmd_start;

                switch (p - c) {

                case 4:
                    if ((c[0] == 'N' || c[0] == 'n')
                        && (c[1] == 'O'|| c[1] == 'o')
                        && (c[2] == 'O'|| c[2] == 'o')
                        && (c[3] == 'P'|| c[3] == 'p'))
                    {
                        s->command = NGX_IMAP_NOOP;

                    } else {
                        goto invalid;
                    }
                    break;

                case 5:
                    if ((c[0] == 'L'|| c[0] == 'l')
                        && (c[1] == 'O'|| c[1] == 'o')
                        && (c[2] == 'G'|| c[2] == 'g')
                        && (c[3] == 'I'|| c[3] == 'i')
                        && (c[4] == 'N'|| c[4] == 'n'))
                    {
                        s->command = NGX_IMAP_LOGIN;

                    } else {
                        goto invalid;
                    }
                    break;

                case 6:
                    if ((c[0] == 'L'|| c[0] == 'l')
                        && (c[1] == 'O'|| c[1] == 'o')
                        && (c[2] == 'G'|| c[2] == 'g')
                        && (c[3] == 'O'|| c[3] == 'o')
                        && (c[4] == 'U'|| c[4] == 'u')
                        && (c[5] == 'T'|| c[5] == 't'))
                    {
                        s->command = NGX_IMAP_LOGOUT;

                    } else {
                        goto invalid;
                    }
                    break;

#if (NGX_MAIL_SSL)
                case 8:
                    if ((c[0] == 'S'|| c[0] == 's')
                        && (c[1] == 'T'|| c[1] == 't')
                        && (c[2] == 'A'|| c[2] == 'a')
                        && (c[3] == 'R'|| c[3] == 'r')
                        && (c[4] == 'T'|| c[4] == 't')
                        && (c[5] == 'T'|| c[5] == 't')
                        && (c[6] == 'L'|| c[6] == 'l')
                        && (c[7] == 'S'|| c[7] == 's'))
                    {
                        s->command = NGX_IMAP_STARTTLS;

                    } else {
                        goto invalid;
                    }
                    break;
#endif

                case 10:
                    if ((c[0] == 'C'|| c[0] == 'c')
                        && (c[1] == 'A'|| c[1] == 'a')
                        && (c[2] == 'P'|| c[2] == 'p')
                        && (c[3] == 'A'|| c[3] == 'a')
                        && (c[4] == 'B'|| c[4] == 'b')
                        && (c[5] == 'I'|| c[5] == 'i')
                        && (c[6] == 'L'|| c[6] == 'l')
                        && (c[7] == 'I'|| c[7] == 'i')
                        && (c[8] == 'T'|| c[8] == 't')
                        && (c[9] == 'Y'|| c[9] == 'y'))
                    {
                        s->command = NGX_IMAP_CAPABILITY;

                    } else {
                        goto invalid;
                    }
                    break;

                case 12:
                    if ((c[0] == 'A'|| c[0] == 'a')
                        && (c[1] == 'U'|| c[1] == 'u')
                        && (c[2] == 'T'|| c[2] == 't')
                        && (c[3] == 'H'|| c[3] == 'h')
                        && (c[4] == 'E'|| c[4] == 'e')
                        && (c[5] == 'N'|| c[5] == 'n')
                        && (c[6] == 'T'|| c[6] == 't')
                        && (c[7] == 'I'|| c[7] == 'i')
                        && (c[8] == 'C'|| c[8] == 'c')
                        && (c[9] == 'A'|| c[9] == 'a')
                        && (c[10] == 'T'|| c[10] == 't')
                        && (c[11] == 'E'|| c[11] == 'e'))
                    {
                        s->command = NGX_IMAP_AUTHENTICATE;

                    } else {
                        goto invalid;
                    }
                    break;

                default:
                    goto invalid;
                }

                switch (ch) {
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;
            }

            if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                goto invalid;
            }

            break;

        case sw_spaces_before_argument:
            switch (ch) {
            case ' ':
                break;
            case CR:
                state = sw_almost_done;
                s->arg_end = p;
                break;
            case LF:
                s->arg_end = p;
                goto done;
            case '"':
                if (s->args.nelts <= 2) {
                    s->quoted = 1;
                    s->arg_start = p + 1;
                    state = sw_argument;
                    break;
                }
                goto invalid;
            case '{':
                if (s->args.nelts <= 2) {
                    state = sw_literal;
                    break;
                }
                goto invalid;
            default:
                if (s->args.nelts <= 2) {
                    s->arg_start = p;
                    state = sw_argument;
                    break;
                }
                goto invalid;
            }
            break;

        case sw_argument:
            if (ch == ' ' && s->quoted) {
                break;
            }

            switch (ch) {
            case '"':
                if (!s->quoted) {
                    break;
                }
                s->quoted = 0;
                /* fall through */
            case ' ':
            case CR:
            case LF:
                arg = ngx_array_push(&s->args);
                if (arg == NULL) {
                    return NGX_ERROR;
                }
                arg->len = p - s->arg_start;
                arg->data = s->arg_start;
                s->arg_start = NULL;

                switch (ch) {
                case '"':
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;
            case '\\':
                if (s->quoted) {
                    s->backslash = 1;
                    state = sw_backslash;
                }
                break;
            }
            break;

        case sw_backslash:
            switch (ch) {
            case CR:
            case LF:
                goto invalid;
            default:
                state = sw_argument;
            }
            break;

        case sw_literal:
            if (ch >= '0' && ch <= '9') {
                s->literal_len = s->literal_len * 10 + (ch - '0');
                break;
            }
            if (ch == '}') {
                state = sw_start_literal_argument;
                break;
            }
            if (ch == '+') {
                state = sw_no_sync_literal_argument;
                break;
            }
            goto invalid;

        case sw_no_sync_literal_argument:
            if (ch == '}') {
                s->no_sync_literal = 1;
                state = sw_start_literal_argument;
                break;
            }
            goto invalid;

        case sw_start_literal_argument:
            switch (ch) {
            case CR:
                break;
            case LF:
                s->buffer->pos = p + 1;
                s->arg_start = p + 1;
                if (s->no_sync_literal == 0) {
                    s->state = sw_literal_argument;
                    return NGX_IMAP_NEXT;
                }
                state = sw_literal_argument;
                s->no_sync_literal = 0;
                break;
            default:
                goto invalid;
            }
            break;

        case sw_literal_argument:
            if (s->literal_len && --s->literal_len) {
                break;
            }

            arg = ngx_array_push(&s->args);
            if (arg == NULL) {
                return NGX_ERROR;
            }
            arg->len = p + 1 - s->arg_start;
            arg->data = s->arg_start;
            s->arg_start = NULL;
            state = sw_end_literal_argument;

            break;

        case sw_end_literal_argument:
            switch (ch) {
            case '{':
                if (s->args.nelts <= 2) {
                    state = sw_literal;
                    break;
                }
                goto invalid;
            case CR:
                state = sw_almost_done;
                break;
            case LF:
                goto done;
            default:
                state = sw_spaces_before_argument;
                break;
            }
            break;

        case sw_almost_done:
            switch (ch) {
            case LF:
                goto done;
            default:
                goto invalid;
            }
        }
    }

    s->buffer->pos = p;
    s->state = state;

    return NGX_AGAIN;

done:

    s->buffer->pos = p + 1;

    if (s->arg_start) {
        arg = ngx_array_push(&s->args);
        if (arg == NULL) {
            return NGX_ERROR;
        }
        arg->len = s->arg_end - s->arg_start;
        arg->data = s->arg_start;

        s->arg_start = NULL;
        s->cmd_start = NULL;
        s->quoted = 0;
        s->no_sync_literal = 0;
        s->literal_len = 0;
    }

    s->state = (s->command != NGX_IMAP_AUTHENTICATE) ? sw_start : sw_argument;

    return NGX_OK;

invalid:

    s->state = sw_start;
    s->quoted = 0;
    s->no_sync_literal = 0;
    s->literal_len = 0;

    return NGX_MAIL_PARSE_INVALID_COMMAND;
}


ngx_int_t
ngx_mail_smtp_parse_command(ngx_mail_session_t *s)
{
    u_char      ch, *p, *c, c0, c1, c2, c3;
    ngx_str_t  *arg;
    enum {
        sw_start = 0,
        sw_spaces_before_argument,
        sw_argument,
        sw_almost_done
    } state;

    state = s->state;

    for (p = s->buffer->pos; p < s->buffer->last; p++) {
        ch = *p;

        switch (state) {

        /* SMTP command */
        case sw_start:
            if (ch == ' ' || ch == CR || ch == LF) {
                c = s->buffer->start;

                if (p - c == 4) {

                    c0 = ngx_toupper(c[0]);
                    c1 = ngx_toupper(c[1]);
                    c2 = ngx_toupper(c[2]);
                    c3 = ngx_toupper(c[3]);

                    if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'O')
                    {
                        s->command = NGX_SMTP_HELO;

                    } else if (c0 == 'E' && c1 == 'H' && c2 == 'L' && c3 == 'O')
                    {
                        s->command = NGX_SMTP_EHLO;

                    } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
                    {
                        s->command = NGX_SMTP_QUIT;

                    } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
                    {
                        s->command = NGX_SMTP_AUTH;

                    } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
                    {
                        s->command = NGX_SMTP_NOOP;

                    } else if (c0 == 'M' && c1 == 'A' && c2 == 'I' && c3 == 'L')
                    {
                        s->command = NGX_SMTP_MAIL;

                    } else if (c0 == 'R' && c1 == 'S' && c2 == 'E' && c3 == 'T')
                    {
                        s->command = NGX_SMTP_RSET;

                    } else if (c0 == 'R' && c1 == 'C' && c2 == 'P' && c3 == 'T')
                    {
                        s->command = NGX_SMTP_RCPT;

                    } else if (c0 == 'V' && c1 == 'R' && c2 == 'F' && c3 == 'Y')
                    {
                        s->command = NGX_SMTP_VRFY;

                    } else if (c0 == 'E' && c1 == 'X' && c2 == 'P' && c3 == 'N')
                    {
                        s->command = NGX_SMTP_EXPN;

                    } else if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'P')
                    {
                        s->command = NGX_SMTP_HELP;

                    } else {
                        goto invalid;
                    }
#if (NGX_MAIL_SSL)
                } else if (p - c == 8) {

                    if ((c[0] == 'S'|| c[0] == 's')
                        && (c[1] == 'T'|| c[1] == 't')
                        && (c[2] == 'A'|| c[2] == 'a')
                        && (c[3] == 'R'|| c[3] == 'r')
                        && (c[4] == 'T'|| c[4] == 't')
                        && (c[5] == 'T'|| c[5] == 't')
                        && (c[6] == 'L'|| c[6] == 'l')
                        && (c[7] == 'S'|| c[7] == 's'))
                    {
                        s->command = NGX_SMTP_STARTTLS;

                    } else {
                        goto invalid;
                    }
#endif
                } else {
                    goto invalid;
                }

                switch (ch) {
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;
            }

            if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
                goto invalid;
            }

            break;

        case sw_spaces_before_argument:
            switch (ch) {
            case ' ':
                break;
            case CR:
                state = sw_almost_done;
                s->arg_end = p;
                break;
            case LF:
                s->arg_end = p;
                goto done;
            default:
                if (s->args.nelts <= 10) {
                    state = sw_argument;
                    s->arg_start = p;
                    break;
                }
                goto invalid;
            }
            break;

        case sw_argument:
            switch (ch) {
            case ' ':
            case CR:
            case LF:
                arg = ngx_array_push(&s->args);
                if (arg == NULL) {
                    return NGX_ERROR;
                }
                arg->len = p - s->arg_start;
                arg->data = s->arg_start;
                s->arg_start = NULL;

                switch (ch) {
                case ' ':
                    state = sw_spaces_before_argument;
                    break;
                case CR:
                    state = sw_almost_done;
                    break;
                case LF:
                    goto done;
                }
                break;

            default:
                break;
            }
            break;

        case sw_almost_done:
            switch (ch) {
            case LF:
                goto done;
            default:
                goto invalid;
            }
        }
    }

    s->buffer->pos = p;
    s->state = state;

    return NGX_AGAIN;

done:

    s->buffer->pos = p + 1;

    if (s->arg_start) {
        arg = ngx_array_push(&s->args);
        if (arg == NULL) {
            return NGX_ERROR;
        }
        arg->len = s->arg_end - s->arg_start;
        arg->data = s->arg_start;
        s->arg_start = NULL;
    }

    s->state = (s->command != NGX_SMTP_AUTH) ? sw_start : sw_argument;

    return NGX_OK;

invalid:

    s->state = sw_start;
    s->arg_start = NULL;

    return NGX_MAIL_PARSE_INVALID_COMMAND;
}


ngx_int_t
ngx_mail_auth_parse(ngx_mail_session_t *s, ngx_connection_t *c)
{
    ngx_str_t                 *arg;

#if (NGX_MAIL_SSL)
    if (ngx_mail_starttls_only(s, c)) {
        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }
#endif

    arg = s->args.elts;

    if (arg[0].len == 5) {

        if (ngx_strncasecmp(arg[0].data, (u_char *) "LOGIN", 5) == 0) {

            if (s->args.nelts == 1) {
                return NGX_MAIL_AUTH_LOGIN;
            }

            if (s->args.nelts == 2) {
                return NGX_MAIL_AUTH_LOGIN_USERNAME;
            }

            return NGX_MAIL_PARSE_INVALID_COMMAND;
        }

        if (ngx_strncasecmp(arg[0].data, (u_char *) "PLAIN", 5) == 0) {

            if (s->args.nelts == 1) {
                return NGX_MAIL_AUTH_PLAIN;
            }

            if (s->args.nelts == 2) {
                return ngx_mail_auth_plain(s, c, 1);
            }
        }

        return NGX_MAIL_PARSE_INVALID_COMMAND;
    }

    if (arg[0].len == 8) {

        if (s->args.nelts != 1) {
            return NGX_MAIL_PARSE_INVALID_COMMAND;
        }

        if (ngx_strncasecmp(arg[0].data, (u_char *) "CRAM-MD5", 8) == 0) {
            return NGX_MAIL_AUTH_CRAM_MD5;
        }
    }

    return NGX_MAIL_PARSE_INVALID_COMMAND;
}