Mercurial > hg > nginx
view src/mail/ngx_mail_imap_module.c @ 9282:acb8548c00e9
HTTP/3: fixed dynamic table overflow.
While inserting a new entry into the dynamic table, first the entry is added,
and then older entries are evicted until table size is within capacity. After
the first step, the number of entries may temporarily exceed the maximum
calculated from capacity by one entry, which previously caused table overflow.
The easiest way to trigger the issue is to keep adding entries with empty names
and values until first eviction.
The issue was introduced by 987bee4363d1.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 28 May 2024 17:18:50 +0400 |
parents | dc955d274130 |
children | 4538c1ffb0f8 |
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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_imap_module.h> static void *ngx_mail_imap_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_str_t ngx_mail_imap_default_capabilities[] = { ngx_string("IMAP4"), ngx_string("IMAP4rev1"), ngx_string("UIDPLUS"), ngx_null_string }; static ngx_conf_bitmask_t ngx_mail_imap_auth_methods[] = { { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED }, { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED }, { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED }, { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED }, { ngx_null_string, 0 } }; static ngx_str_t ngx_mail_imap_auth_methods_names[] = { ngx_string("AUTH=PLAIN"), ngx_string("AUTH=LOGIN"), ngx_null_string, /* APOP */ ngx_string("AUTH=CRAM-MD5"), ngx_string("AUTH=EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_imap_protocol = { ngx_string("imap"), ngx_string("\x04imap"), { 143, 993, 0, 0 }, NGX_MAIL_IMAP_PROTOCOL, ngx_mail_imap_init_session, ngx_mail_imap_init_protocol, ngx_mail_imap_parse_command, ngx_mail_imap_auth_state, ngx_string("* BAD internal server error" CRLF), ngx_string("* BYE SSL certificate error" CRLF), ngx_string("* BYE No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_imap_commands[] = { { ngx_string("imap_client_buffer"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, client_buffer_size), NULL }, { ngx_string("imap_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, capabilities), NULL }, { ngx_string("imap_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_imap_srv_conf_t, auth_methods), &ngx_mail_imap_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_imap_module_ctx = { &ngx_mail_imap_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_imap_create_srv_conf, /* create server configuration */ ngx_mail_imap_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_imap_module = { NGX_MODULE_V1, &ngx_mail_imap_module_ctx, /* module context */ ngx_mail_imap_commands, /* module directives */ NGX_MAIL_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static void * ngx_mail_imap_create_srv_conf(ngx_conf_t *cf) { ngx_mail_imap_srv_conf_t *iscf; iscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_imap_srv_conf_t)); if (iscf == NULL) { return NULL; } iscf->client_buffer_size = NGX_CONF_UNSET_SIZE; if (ngx_array_init(&iscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return iscf; } static char * ngx_mail_imap_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_imap_srv_conf_t *prev = parent; ngx_mail_imap_srv_conf_t *conf = child; u_char *p, *auth; size_t size; ngx_str_t *c, *d; ngx_uint_t i, m; ngx_conf_merge_size_value(conf->client_buffer_size, prev->client_buffer_size, (size_t) ngx_pagesize); ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED)); if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } if (conf->capabilities.nelts == 0) { for (d = ngx_mail_imap_default_capabilities; d->len; d++) { c = ngx_array_push(&conf->capabilities); if (c == NULL) { return NGX_CONF_ERROR; } *c = *d; } } size = sizeof("* CAPABILITY" CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += 1 + c[i].len; } for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { size += 1 + ngx_mail_imap_auth_methods_names[i].len; } } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; p = ngx_cpymem(p, "* CAPABILITY", sizeof("* CAPABILITY") - 1); for (i = 0; i < conf->capabilities.nelts; i++) { *p++ = ' '; p = ngx_cpymem(p, c[i].data, c[i].len); } auth = p; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (m & conf->auth_methods) { *p++ = ' '; p = ngx_cpymem(p, ngx_mail_imap_auth_methods_names[i].data, ngx_mail_imap_auth_methods_names[i].len); } } *p++ = CR; *p = LF; size += sizeof(" STARTTLS") - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_capability.len = size; conf->starttls_capability.data = p; p = ngx_cpymem(p, conf->capability.data, conf->capability.len - (sizeof(CRLF) - 1)); p = ngx_cpymem(p, " STARTTLS", sizeof(" STARTTLS") - 1); *p++ = CR; *p = LF; size = (auth - conf->capability.data) + sizeof(CRLF) - 1 + sizeof(" STARTTLS LOGINDISABLED") - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_only_capability.len = size; conf->starttls_only_capability.data = p; p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data); p = ngx_cpymem(p, " STARTTLS LOGINDISABLED", sizeof(" STARTTLS LOGINDISABLED") - 1); *p++ = CR; *p = LF; return NGX_CONF_OK; }