Mercurial > hg > nginx
view src/mail/ngx_mail_parse.c @ 7843:b38728495e1a
Mail: IMAP pipelining support.
The change is mostly the same as the SMTP one (04e43d03e153 and 3f5d0af4e40a),
and ensures that nginx is able to properly handle or reject multiple IMAP
commands. The s->cmd field is not really used and set for consistency.
Non-synchronizing literals handling in invalid/unknown commands is limited,
so when a non-synchronizing literal is detected at the end of a discarded
line, the connection is closed.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Wed, 19 May 2021 03:13:28 +0300 |
| parents | 4b15f1b92100 |
| children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> #include <ngx_mail_pop3_module.h> #include <ngx_mail_imap_module.h> #include <ngx_mail_smtp_module.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_command, sw_invalid, 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: s->cmd_start = p; state = sw_command; /* fall through */ case sw_command: if (ch == ' ' || ch == CR || ch == LF) { c = s->cmd_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; } s->cmd.data = s->cmd_start; s->cmd.len = p - s->cmd_start; 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_invalid: goto invalid; case sw_spaces_before_argument: switch (ch) { case ' ': break; case CR: state = sw_almost_done; break; case LF: 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; s->state = (s->command != NGX_POP3_AUTH) ? sw_start : sw_argument; return NGX_OK; invalid: s->state = sw_invalid; /* skip invalid command till LF */ for ( /* void */ ; p < s->buffer->last; p++) { if (*p == LF) { s->state = sw_start; s->buffer->pos = p + 1; return NGX_MAIL_PARSE_INVALID_COMMAND; } } s->buffer->pos = p; return NGX_AGAIN; } ngx_int_t ngx_mail_imap_parse_command(ngx_mail_session_t *s) { u_char ch, *p, *c, *dst, *src, *end; ngx_str_t *arg; enum { sw_start = 0, sw_tag, sw_invalid, 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: s->tag_start = p; state = sw_tag; /* fall through */ case sw_tag: switch (ch) { case ' ': s->tag.len = p - s->tag_start + 1; s->tag.data = s->tag_start; state = sw_spaces_before_command; break; case CR: case LF: goto invalid; default: if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z') && (ch < '0' || ch > '9') && ch != '-' && ch != '.' && ch != '_') { goto invalid; } if (p - s->tag_start > 31) { goto invalid; } break; } break; case sw_invalid: goto invalid; case sw_spaces_before_command: switch (ch) { case ' ': break; case CR: case LF: goto invalid; 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; } s->cmd.data = s->cmd_start; s->cmd.len = p - s->cmd_start; 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; break; case LF: 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; if (s->backslash) { dst = s->arg_start; end = p; for (src = dst; src < end; dst++) { *dst = *src; if (*src++ == '\\') { *dst = *src++; } } arg->len = dst - s->arg_start; s->backslash = 0; } 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; s->state = (s->command != NGX_IMAP_AUTHENTICATE) ? sw_start : sw_argument; return NGX_OK; invalid: s->state = sw_invalid; s->quoted = 0; s->backslash = 0; s->no_sync_literal = 0; s->literal_len = 0; /* skip invalid command till LF */ for ( /* void */ ; p < s->buffer->last; p++) { if (*p == LF) { s->state = sw_start; s->buffer->pos = p + 1; /* detect non-synchronizing literals */ if ((size_t) (p - s->buffer->start) > sizeof("{1+}") - 1) { p--; if (*p == CR) { p--; } if (*p == '}' && *(p - 1) == '+') { s->quit = 1; } } return NGX_MAIL_PARSE_INVALID_COMMAND; } } s->buffer->pos = p; return NGX_AGAIN; } 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_command, sw_invalid, 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: s->cmd_start = p; state = sw_command; /* fall through */ case sw_command: if (ch == ' ' || ch == CR || ch == LF) { c = s->cmd_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; } s->cmd.data = s->cmd_start; s->cmd.len = p - s->cmd_start; 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_invalid: goto invalid; case sw_spaces_before_argument: switch (ch) { case ' ': break; case CR: state = sw_almost_done; break; case LF: 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; s->state = (s->command != NGX_SMTP_AUTH) ? sw_start : sw_argument; return NGX_OK; invalid: s->state = sw_invalid; /* skip invalid command till LF */ for ( /* void */ ; p < s->buffer->last; p++) { if (*p == LF) { s->state = sw_start; s->buffer->pos = p + 1; return NGX_MAIL_PARSE_INVALID_COMMAND; } } s->buffer->pos = p; return NGX_AGAIN; } 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 if (s->args.nelts == 0) { return NGX_MAIL_PARSE_INVALID_COMMAND; } 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 (ngx_strncasecmp(arg[0].data, (u_char *) "CRAM-MD5", 8) == 0) { if (s->args.nelts != 1) { return NGX_MAIL_PARSE_INVALID_COMMAND; } return NGX_MAIL_AUTH_CRAM_MD5; } if (ngx_strncasecmp(arg[0].data, (u_char *) "EXTERNAL", 8) == 0) { if (s->args.nelts == 1) { return NGX_MAIL_AUTH_EXTERNAL; } if (s->args.nelts == 2) { return ngx_mail_auth_external(s, c, 1); } } return NGX_MAIL_PARSE_INVALID_COMMAND; } return NGX_MAIL_PARSE_INVALID_COMMAND; }