plugins/pop3-migration/pop3-migration-plugin.c

	pop3-migration-plugin.c revision 615b4468c088b674aad109c9420d7d5c14eebf43
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "lib.h"
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen#include "array.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "istream.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "istream-header-filter.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "str.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "sha1.h"
f1901fd21906911f7be075c965ac882f6a87b4c3Timo Sirainen#include "message-size.h"
63a61b7a739ae0f3f520215137d9c50f94d0f34fTimo Sirainen#include "message-header-hash.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "message-header-parser.h"
18565c69efcd7db003dbf27cf625ed822e889fb1Timo Sirainen#include "mail-cache.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "mail-namespace.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "mail-search-build.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "index-storage.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "index-mail.h"
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen#include "pop3-migration-plugin.h"
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen#define POP3_MIGRATION_CONTEXT(obj) \
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    MODULE_CONTEXT(obj, pop3_migration_storage_module)
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen#define POP3_MIGRATION_CONTEXT_REQUIRE(obj) \
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    MODULE_CONTEXT_REQUIRE(obj, pop3_migration_storage_module)
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen#define POP3_MIGRATION_MAIL_CONTEXT(obj) \
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    MODULE_CONTEXT_REQUIRE(obj, pop3_migration_mail_module)
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainenstruct msg_map_common {
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    /* sha1(header) - set only when needed */
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    unsigned char hdr_sha1[SHA1_RESULTLEN];
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    bool hdr_sha1_set:1;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen};
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainenstruct pop3_uidl_map {
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    struct msg_map_common common;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
af1f4b17a92ca7b2661737e65c7849df289d3070Timo Sirainen    uint32_t pop3_seq;
af1f4b17a92ca7b2661737e65c7849df289d3070Timo Sirainen    uint32_t imap_uid;
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen
f1901fd21906911f7be075c965ac882f6a87b4c3Timo Sirainen    /* UIDL */
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    const char *pop3_uidl;
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen    /* LIST size */
01cbf4ac5d44137ab434791be7f838d98d0fcf3bTimo Sirainen    uoff_t size;
fdc557286bc9f92c5f3bb49096ff6e2bcec0ea79Timo Sirainen};
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainen
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainenstruct imap_msg_map {
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    struct msg_map_common common;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    uint32_t uid, pop3_seq;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    uoff_t psize;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    const char *pop3_uidl;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen};
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainenstruct pop3_migration_mail_storage {
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    union mail_storage_module_context module_ctx;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    const char *pop3_box_vname;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    ARRAY(struct pop3_uidl_map) pop3_uidl_map;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool all_mailboxes:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool pop3_all_hdr_sha1_set:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool ignore_missing_uidls:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool ignore_extra_uidls:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool skip_size_check:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool skip_uidl_cache:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen};
d30da25fb6be1f1c667d93767c9194000194b618Timo Sirainen
d30da25fb6be1f1c667d93767c9194000194b618Timo Sirainenstruct pop3_migration_mailbox {
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    union mailbox_module_context module_ctx;
597dce34068d603fb759b4dff404b34049213e51Timo Sirainen
63a61b7a739ae0f3f520215137d9c50f94d0f34fTimo Sirainen    ARRAY(struct imap_msg_map) imap_msg_map;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    unsigned int first_unfound_idx;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    struct mail_cache_field cache_field;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool cache_field_registered:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool uidl_synced:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    bool uidl_sync_failed:1;
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen};
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen/* NOTE: these headers must be sorted */
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainenstatic const char *hdr_hash_skip_headers[] = {
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "Content-Length",
f1901fd21906911f7be075c965ac882f6a87b4c3Timo Sirainen    "Return-Path", /* Yahoo IMAP has Return-Path, Yahoo POP3 doesn't */
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    "Status",
f1901fd21906911f7be075c965ac882f6a87b4c3Timo Sirainen    "X-IMAP",
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "X-IMAPbase",
6060b7c8edf8fce73470d0df6a2479b69b01c537Timo Sirainen    "X-Keywords",
7f773564b94e6054a40d3785cb63c29f1e4d4deeTimo Sirainen    "X-Message-Flag",
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "X-Status",
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "X-UID",
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "X-UIDL",
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen    "X-Yahoo-Newman-Property"
fe6c1556d3529a6376d4cbb3766c34aebde0de99Timo Sirainen};
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainenconst char *pop3_migration_plugin_version = DOVECOT_ABI_VERSION;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic MODULE_CONTEXT_DEFINE_INIT(pop3_migration_storage_module,
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                  &mail_storage_module_register);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic MODULE_CONTEXT_DEFINE_INIT(pop3_migration_mail_module,
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                  &mail_module_register);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainenstatic int imap_msg_map_uid_cmp(const struct imap_msg_map *map1,
8000c86be02008b74acc71fa422444dc432e2c01Timo Sirainen                const struct imap_msg_map *map2)
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen{
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    if (map1->uid < map2->uid)
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen        return -1;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    if (map1->uid > map2->uid)
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen        return 1;
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainen    return 0;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen}
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainenstatic int pop3_uidl_map_pop3_seq_cmp(const struct pop3_uidl_map *map1,
345212e8f61ebf14ff4f80df26df9e655eb5121eTimo Sirainen                      const struct pop3_uidl_map *map2)
345212e8f61ebf14ff4f80df26df9e655eb5121eTimo Sirainen{
345212e8f61ebf14ff4f80df26df9e655eb5121eTimo Sirainen    if (map1->pop3_seq < map2->pop3_seq)
345212e8f61ebf14ff4f80df26df9e655eb5121eTimo Sirainen        return -1;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    if (map1->pop3_seq > map2->pop3_seq)
345212e8f61ebf14ff4f80df26df9e655eb5121eTimo Sirainen        return 1;
8000c86be02008b74acc71fa422444dc432e2c01Timo Sirainen    return 0;
8000c86be02008b74acc71fa422444dc432e2c01Timo Sirainen}
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic int pop3_uidl_map_uidl_cmp(const struct pop3_uidl_map *map1,
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                  const struct pop3_uidl_map *map2)
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen{
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen    return strcmp(map1->pop3_uidl, map2->pop3_uidl);
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen}
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainenstatic int imap_msg_map_uidl_cmp(const struct imap_msg_map *map1,
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen                 const struct imap_msg_map *map2)
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen{
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen    return null_strcmp(map1->pop3_uidl, map2->pop3_uidl);
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen}
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainenstatic int pop3_uidl_map_hdr_cmp(const struct pop3_uidl_map *map1,
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen                 const struct pop3_uidl_map *map2)
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen{
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen    return memcmp(map1->common.hdr_sha1, map2->common.hdr_sha1,
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen              sizeof(map1->common.hdr_sha1));
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen}
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainenstatic int imap_msg_map_hdr_cmp(const struct imap_msg_map *map1,
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                const struct imap_msg_map *map2)
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen{
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    return memcmp(map1->common.hdr_sha1, map2->common.hdr_sha1,
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen              sizeof(map1->common.hdr_sha1));
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen}
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainenstruct pop3_hdr_context {
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    bool have_eoh;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    bool stop;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen};
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic bool header_name_is_valid(const char *name)
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen{
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen    unsigned int i;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    for (i = 0; name[i] != '\0'; i++) {
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen        if ((uint8_t)name[i] <= 0x20 || name[i] >= 0x7f)
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen            return FALSE;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    }
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    return TRUE;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen}
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainenstatic bool header_value_want_skip(const struct message_header_line *hdr)
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen{
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    for (size_t i = 0; i < hdr->value_len; i++) {
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen        if (hdr->value[i] != ' ' && hdr->value[i] != '\t')
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen            return FALSE;
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    }
a0b0d629931773c17a236f6214adbe0e13b9b3fdTimo Sirainen    /* "header: \r\n \r\n" - Zimbra's BODY[HEADER] strips this line away. */
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    return TRUE;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen}
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic void
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenpop3_header_filter_callback(struct header_filter_istream *input ATTR_UNUSED,
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen                struct message_header_line *hdr,
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen                bool *matched, struct pop3_hdr_context *ctx)
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen{
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen    if (hdr == NULL)
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen        return;
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen    if (hdr->eoh) {
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen        ctx->have_eoh = TRUE;
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen        if (ctx->stop)
a1808be0774cbcb28fec45341aabf803ec44bae5Timo Sirainen            *matched = TRUE;
a1808be0774cbcb28fec45341aabf803ec44bae5Timo Sirainen    } else {
a1808be0774cbcb28fec45341aabf803ec44bae5Timo Sirainen        if (strspn(hdr->name, "\r") == hdr->name_len) {
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen            /* CR+CR+LF - some servers stop the header processing
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen             here while others don't. To make sure they can be
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen             matched correctly we want to stop here entirely. */
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen            ctx->stop = TRUE;
c74ea62a27878910e3ca1614ca055d7e2b3b00d5Timo Sirainen        } else if (!hdr->continued && hdr->middle_len == 0) {
c74ea62a27878910e3ca1614ca055d7e2b3b00d5Timo Sirainen            /* not a valid "key: value" header -
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen               Zimbra's BODY[HEADER] strips this line away. */
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen            *matched = TRUE;
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen        } else if (hdr->continued && header_value_want_skip(hdr)) {
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen            *matched = TRUE;
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen        }
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen        if (ctx->stop)
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen            *matched = TRUE;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen        else if (!header_name_is_valid(hdr->name)) {
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen            /* Yahoo IMAP drops headers with invalid names, while
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen               Yahoo POP3 preserves them. Drop them all. */
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen            *matched = TRUE;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen        }
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    }
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen}
b2ecd50bb98c44816cb07c17aa17fae2b425f941Timo Sirainen
db7c9201c88e3d9bee10485194ee5b0c67249916Timo Sirainenint pop3_migration_get_hdr_sha1(uint32_t mail_seq, struct istream *input,
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                unsigned char sha1_r[STATIC_ARRAY SHA1_RESULTLEN],
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                bool *have_eoh_r)
992a13add4eea0810e4db0f042a595dddf85536aTimo Sirainen{
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    const unsigned char *data;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    size_t size;
b5e6f6f27c1461f0f9f202615eeb738a645188c3Timo Sirainen    struct message_header_hash_context hash_ctx;
db7c9201c88e3d9bee10485194ee5b0c67249916Timo Sirainen    struct sha1_ctxt sha1_ctx;
18565c69efcd7db003dbf27cf625ed822e889fb1Timo Sirainen    struct pop3_hdr_context hdr_ctx;
18565c69efcd7db003dbf27cf625ed822e889fb1Timo Sirainen
18565c69efcd7db003dbf27cf625ed822e889fb1Timo Sirainen    i_zero(&hdr_ctx);
185ed0142fbbfb86e7a98519e7c6f11ec00723cdTimo Sirainen    /* hide headers that might change or be different in IMAP vs. POP3 */
59151b71059df1190acd75d8717ed04a7920c862Timo Sirainen    input = i_stream_create_header_filter(input, HEADER_FILTER_HIDE_BODY |
59151b71059df1190acd75d8717ed04a7920c862Timo Sirainen                HEADER_FILTER_EXCLUDE | HEADER_FILTER_NO_CR,
59151b71059df1190acd75d8717ed04a7920c862Timo Sirainen                hdr_hash_skip_headers,
d5cebe7f98e63d4e2822863ef2faa4971e8b3a5dTimo Sirainen                N_ELEMENTS(hdr_hash_skip_headers),
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen                pop3_header_filter_callback, &hdr_ctx);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    sha1_init(&sha1_ctx);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    i_zero(&hash_ctx);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    while (i_stream_read_more(input, &data, &size) > 0) {
fdc557286bc9f92c5f3bb49096ff6e2bcec0ea79Timo Sirainen        message_header_hash_more(&hash_ctx, &hash_method_sha1, &sha1_ctx,
fdc557286bc9f92c5f3bb49096ff6e2bcec0ea79Timo Sirainen                     MESSAGE_HEADER_HASH_MAX_VERSION,
fdc557286bc9f92c5f3bb49096ff6e2bcec0ea79Timo Sirainen                     data, size);
a12399903f415a7e14c2816cffa2f7a09dcbb097Timo Sirainen        i_stream_skip(input, size);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    }
16c89b1260c9d07c01c83a9219424d3727069b2eTimo Sirainen    if (input->stream_errno != 0) {
16c89b1260c9d07c01c83a9219424d3727069b2eTimo Sirainen        i_error("pop3_migration: Failed to read header for msg %u: %s",
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen            mail_seq, i_stream_get_error(input));
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen        i_stream_unref(&input);
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen        return -1;
90adcaa0a00eba29b7fbd50ca66be11c8d086d6aTimo Sirainen    }
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen    sha1_result(&sha1_ctx, sha1_r);
d67fde1a8ebc1d85704c5986d8f93aae97eccef3Timo Sirainen    i_stream_unref(&input);
87460b08cb97b31cde640d4975a6aa2c1d0e7226Timo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    *have_eoh_r = hdr_ctx.have_eoh;
87460b08cb97b31cde640d4975a6aa2c1d0e7226Timo Sirainen    return 0;
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen}
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainenstatic unsigned int get_cache_idx(struct mail *mail)
16c89b1260c9d07c01c83a9219424d3727069b2eTimo Sirainen{
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(mail->box);
8fcff4c5b52f24d9c681805fdf06b486f1d0fcbeTimo Sirainen
    if (mbox->cache_field_registered)
        return mbox->cache_field.idx;

    mbox->cache_field.name = "pop3-migration.hdr";
    mbox->cache_field.type = MAIL_CACHE_FIELD_FIXED_SIZE;
    mbox->cache_field.field_size = SHA1_RESULTLEN;
    mail_cache_register_fields(mail->box->cache, &mbox->cache_field, 1);
    mbox->cache_field_registered = TRUE;
    return mbox->cache_field.idx;
}

static int
get_hdr_sha1(struct mail *mail, unsigned char sha1_r[STATIC_ARRAY SHA1_RESULTLEN])
{
    struct istream *input;
    const char *errstr;
    enum mail_error error;
    bool have_eoh;
    int ret;

    if (mail_get_hdr_stream(mail, NULL, &input) < 0) {
        errstr = mailbox_get_last_internal_error(mail->box, &error);
        i_error("pop3_migration: Failed to get header for msg %u: %s",
            mail->seq, errstr);
        return error == MAIL_ERROR_EXPUNGED ? 0 : -1;
    }
    if (pop3_migration_get_hdr_sha1(mail->seq, input, sha1_r, &have_eoh) < 0)
        return -1;
    if (have_eoh) {
        struct index_mail *imail = (struct index_mail *)mail;

        index_mail_cache_add_idx(imail, get_cache_idx(mail),
                     sha1_r, SHA1_RESULTLEN);
        return 1;
    }

    /* The empty "end of headers" line is missing. Either this means that
       the headers ended unexpectedly (which is ok) or that the remote
       server is buggy. Some servers have problems with

       1) header line continuations that contain only whitespace and
       2) headers that have no ":". The header gets truncated when such
       line is reached.

       At least Oracle IMS IMAP FETCH BODY[HEADER] handles 1) by not
       returning the whitespace line and 2) by returning the line but
       truncating the rest. POP3 TOP instead returns the entire header.
       This causes the IMAP and POP3 hashes not to match.

       If there's LF+CR+CR+LF in the middle of headers, Courier IMAP's
       FETCH BODY[HEADER] stops after that, but Courier POP3's TOP doesn't.

       So we'll try to avoid this by falling back to full FETCH BODY[]
       (and/or RETR) and we'll parse the header ourself from it. This
       should work around any similar bugs in all IMAP/POP3 servers. */
    if (mail_get_stream_because(mail, NULL, NULL, "pop3-migration", &input) < 0) {
        errstr = mailbox_get_last_internal_error(mail->box, &error);
        i_error("pop3_migration: Failed to get body for msg %u: %s",
            mail->seq, errstr);
        return error == MAIL_ERROR_EXPUNGED ? 0 : -1;
    }
    ret = pop3_migration_get_hdr_sha1(mail->seq, input, sha1_r, &have_eoh);
    if (ret == 0) {
        if (!have_eoh)
            i_warning("pop3_migration: Truncated email with UID %u stored as truncated", mail->uid);
        struct index_mail *imail = (struct index_mail *)mail;
        index_mail_cache_add_idx(imail, get_cache_idx(mail),
                     sha1_r, SHA1_RESULTLEN);
        return 1;
    } else {
        return -1;
    }
}

static bool
get_cached_hdr_sha1(struct mail *mail, buffer_t *cache_buf,
            unsigned char sha1_r[STATIC_ARRAY SHA1_RESULTLEN])
{
    struct index_mail *imail = (struct index_mail *)mail;

    buffer_set_used_size(cache_buf, 0);
    if (index_mail_cache_lookup_field(imail, cache_buf,
                      get_cache_idx(mail)) > 0 &&
        cache_buf->used == SHA1_RESULTLEN) {
        memcpy(sha1_r, cache_buf->data, cache_buf->used);
        return TRUE;
    }
    return FALSE;
}

static struct mailbox *pop3_mailbox_alloc(struct mail_storage *storage)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(storage);
    struct mail_namespace *ns;
    struct mailbox *box;

    ns = mail_namespace_find(storage->user->namespaces,
                 mstorage->pop3_box_vname);
    i_assert(ns != NULL);
    box = mailbox_alloc(ns->list, mstorage->pop3_box_vname,
                MAILBOX_FLAG_READONLY | MAILBOX_FLAG_POP3_SESSION);
    mailbox_set_reason(box, "pop3_migration");
    return box;
}

static int pop3_map_read(struct mail_storage *storage, struct mailbox *pop3_box)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(storage);
    struct mailbox_transaction_context *t;
    struct mail_search_args *search_args;
    struct mail_search_context *ctx;
    struct mail *mail;
    struct pop3_uidl_map *map;
    const char *uidl;
    uoff_t size = (uoff_t)-1;
    int ret = 0;

    if (array_is_created(&mstorage->pop3_uidl_map)) {
        /* already read these, just reset the imap_uids */
        array_foreach_modifiable(&mstorage->pop3_uidl_map, map)
            map->imap_uid = 0;
        return 0;
    }
    i_array_init(&mstorage->pop3_uidl_map, 128);

    if (mailbox_sync(pop3_box, 0) < 0) {
        i_error("pop3_migration: Couldn't sync mailbox %s: %s",
            pop3_box->vname, mailbox_get_last_internal_error(pop3_box, NULL));
        return -1;
    }

    t = mailbox_transaction_begin(pop3_box, 0, __func__);
    search_args = mail_search_build_init();
    mail_search_build_add_all(search_args);
    ctx = mailbox_search_init(t, search_args, NULL,
                  mstorage->skip_size_check ? 0 :
                  MAIL_FETCH_PHYSICAL_SIZE, NULL);
    mail_search_args_unref(&search_args);

    while (mailbox_search_next(ctx, &mail)) {
        /* get the size with LIST instead of RETR */
        mail->lookup_abort = MAIL_LOOKUP_ABORT_READ_MAIL;

        if (mstorage->skip_size_check)
            ;
        else if (mail_get_physical_size(mail, &size) < 0) {
            i_error("pop3_migration: Failed to get size for msg %u: %s",
                mail->seq,
                mailbox_get_last_internal_error(pop3_box, NULL));
            ret = -1;
            break;
        }
        mail->lookup_abort = MAIL_LOOKUP_ABORT_NEVER;

        if (mail_get_special(mail, MAIL_FETCH_UIDL_BACKEND, &uidl) < 0) {
            i_error("pop3_migration: Failed to get UIDL for msg %u: %s",
                mail->seq,
                mailbox_get_last_internal_error(pop3_box, NULL));
            ret = -1;
            break;
        }
        if (*uidl == '\0') {
            i_warning("pop3_migration: UIDL for msg %u is empty",
                  mail->seq);
            continue;
        }

        map = array_append_space(&mstorage->pop3_uidl_map);
        map->pop3_seq = mail->seq;
        map->pop3_uidl = p_strdup(storage->pool, uidl);
        map->size = size;
    }

    if (mailbox_search_deinit(&ctx) < 0) {
        i_error("pop3_migration: Failed to search all POP3 mails: %s",
            mailbox_get_last_internal_error(pop3_box, NULL));
        ret = -1;
    }
    (void)mailbox_transaction_commit(&t);
    return ret;
}

static void
pop3_map_read_cached_hdr_hashes(struct mailbox_transaction_context *t,
                struct mail_search_args *search_args,
                struct array *msg_map)
{
    struct mail_search_context *ctx;
    struct mail *mail;
    struct msg_map_common *map;
    buffer_t *cache_buf;

    ctx = mailbox_search_init(t, search_args, NULL, 0, NULL);
    cache_buf = t_buffer_create(SHA1_RESULTLEN);

    while (mailbox_search_next(ctx, &mail)) {
        map = array_idx_modifiable_i(msg_map, mail->seq-1);

        if (get_cached_hdr_sha1(mail, cache_buf, map->hdr_sha1))
            map->hdr_sha1_set = TRUE;
    }

    if (mailbox_search_deinit(&ctx) < 0) {
        i_warning("pop3_migration: Failed to search all cached POP3 header hashes: %s - ignoring",
              mailbox_get_last_internal_error(t->box, NULL));
    }
}

static void map_remove_found_seqs(struct mail_search_arg *search_arg,
                  struct array *msg_map, uint32_t seq1)
{
    const struct msg_map_common *map;
    uint32_t seq, count = array_count_i(msg_map);

    i_assert(search_arg->type == SEARCH_SEQSET);

    for (seq = seq1; seq <= count; seq++) {
        map = array_idx_i(msg_map, seq-1);
        if (map->hdr_sha1_set)
            seq_range_array_remove(&search_arg->value.seqset, seq);
    }
}

static int
map_read_hdr_hashes(struct mailbox *box, struct array *msg_map, uint32_t seq1)
{
        struct mailbox_transaction_context *t;
    struct mail_search_args *search_args;
    struct mail_search_context *ctx;
    struct mail *mail;
    struct msg_map_common *map;
    int ret = 0;

    t = mailbox_transaction_begin(box, 0, __func__);
    /* get all the cached hashes */
    search_args = mail_search_build_init();
    mail_search_build_add_seqset(search_args, seq1, array_count_i(msg_map));
    pop3_map_read_cached_hdr_hashes(t, search_args, msg_map);
    /* read all the non-cached hashes. doing this in two passes allows
       us to set wanted_fields=MAIL_FETCH_STREAM_HEADER, which allows
       prefetching to work without downloading all the headers even
       for mails that already are cached. */
    map_remove_found_seqs(search_args->args, msg_map, seq1);
    ctx = mailbox_search_init(t, search_args, NULL,
                  MAIL_FETCH_STREAM_HEADER, NULL);
    mail_search_args_unref(&search_args);

    while (mailbox_search_next(ctx, &mail)) {
        map = array_idx_modifiable_i(msg_map, mail->seq-1);

        if ((ret = get_hdr_sha1(mail, map->hdr_sha1)) < 0) {
            ret = -1;
            break;
        }
        if (ret > 0)
            map->hdr_sha1_set = TRUE;
    }

    if (mailbox_search_deinit(&ctx) < 0) {
        i_error("pop3_migration: Failed to search all mail headers: %s",
            mailbox_get_last_internal_error(box, NULL));
        ret = -1;
    }
    (void)mailbox_transaction_commit(&t);
    return ret < 0 ? -1 : 0;
}

static int
pop3_map_read_hdr_hashes(struct mail_storage *storage, struct mailbox *pop3_box,
             unsigned first_seq)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(storage);

    if (mstorage->pop3_all_hdr_sha1_set)
        return 0;
    if (mstorage->all_mailboxes) {
        /* we may be matching against multiple mailboxes.
           read all the hashes only once. */
        first_seq = 1;
    }

    if (map_read_hdr_hashes(pop3_box, &mstorage->pop3_uidl_map.arr,
                first_seq) < 0)
        return -1;

    if (first_seq == 1)
        mstorage->pop3_all_hdr_sha1_set = TRUE;
    return 0;
}

static int imap_map_read(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct index_mailbox_context *ibox = INDEX_STORAGE_CONTEXT(box);
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(box->storage);
    const unsigned int uidl_cache_idx =
        ibox->cache_fields[MAIL_CACHE_POP3_UIDL].idx;
    struct mailbox_status status;
        struct mailbox_transaction_context *t;
    struct mail_search_args *search_args;
    struct mail_search_context *ctx;
    struct mail *mail;
    struct imap_msg_map *map;
    uoff_t psize = (uoff_t)-1;
    string_t *uidl;
    int ret = 0;

    mailbox_get_open_status(box, STATUS_MESSAGES, &status);

    i_assert(!array_is_created(&mbox->imap_msg_map));
    p_array_init(&mbox->imap_msg_map, box->pool, status.messages);

    t = mailbox_transaction_begin(box, 0, __func__);
    search_args = mail_search_build_init();
    mail_search_build_add_all(search_args);
    ctx = mailbox_search_init(t, search_args, NULL,
                  mstorage->skip_size_check ? 0 :
                  MAIL_FETCH_PHYSICAL_SIZE, NULL);
    mail_search_args_unref(&search_args);

    uidl = t_str_new(64);
    while (mailbox_search_next(ctx, &mail)) {
        if (mstorage->skip_size_check)
            ;
        else if (mail_get_physical_size(mail, &psize) < 0) {
            i_error("pop3_migration: Failed to get psize for imap uid %u: %s",
                mail->uid,
                mailbox_get_last_internal_error(box, NULL));
            ret = -1;
            break;
        }

        if (!mstorage->skip_uidl_cache) {
            str_truncate(uidl, 0);
            (void)mail_cache_lookup_field(mail->transaction->cache_view,
                              uidl, mail->seq, uidl_cache_idx);
        }

        map = array_append_space(&mbox->imap_msg_map);
        map->uid = mail->uid;
        map->psize = psize;
        map->pop3_uidl = p_strdup_empty(box->pool, str_c(uidl));
    }

    if (mailbox_search_deinit(&ctx) < 0) {
        i_error("pop3_migration: Failed to search all IMAP mails: %s",
            mailbox_get_last_internal_error(box, NULL));
        ret = -1;
    }
    (void)mailbox_transaction_commit(&t);
    return ret;
}

static int imap_map_read_hdr_hashes(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);

    return map_read_hdr_hashes(box, &mbox->imap_msg_map.arr,
                   mbox->first_unfound_idx+1);
}

static void pop3_uidl_assign_cached(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(box->storage);
    struct pop3_uidl_map *pop3_map;
    struct imap_msg_map *imap_map;
    unsigned int imap_idx, pop3_idx, pop3_count, imap_count;
    int ret;

    if (mstorage->skip_uidl_cache)
        return;

    array_sort(&mstorage->pop3_uidl_map, pop3_uidl_map_uidl_cmp);
    array_sort(&mbox->imap_msg_map, imap_msg_map_uidl_cmp);

    pop3_map = array_get_modifiable(&mstorage->pop3_uidl_map, &pop3_count);
    imap_map = array_get_modifiable(&mbox->imap_msg_map, &imap_count);

    /* see if we can match the messages using sizes */
    for (imap_idx = pop3_idx = 0; imap_idx < imap_count; imap_idx++) {
        if (imap_map[imap_idx].pop3_uidl == NULL)
            continue;

        ret = 1;
        for (; pop3_idx < pop3_count; pop3_idx++) {
            ret = strcmp(imap_map[imap_idx].pop3_uidl,
                     pop3_map[pop3_idx].pop3_uidl);
            if (ret >= 0)
                break;
        }
        if (ret == 0) {
            imap_map[imap_idx].pop3_seq =
                pop3_map[pop3_idx].pop3_seq;
            pop3_map[pop3_idx].imap_uid = imap_map[imap_idx].uid;
        }
    }
}

static bool pop3_uidl_assign_by_size(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(box->storage);
    struct pop3_uidl_map *pop3_map;
    struct imap_msg_map *imap_map;
    unsigned int i, pop3_count, imap_count, count;
    unsigned int size_match = 0, uidl_match = 0;

    pop3_map = array_get_modifiable(&mstorage->pop3_uidl_map, &pop3_count);
    imap_map = array_get_modifiable(&mbox->imap_msg_map, &imap_count);
    count = I_MIN(pop3_count, imap_count);

    /* see if we can match the messages using sizes */
    for (i = 0; i < count; i++) {
        if (imap_map[i].pop3_uidl != NULL) {
            /* some of the UIDLs were already found cached. */
            if (strcmp(pop3_map[i].pop3_uidl, imap_map[i].pop3_uidl) == 0) {
                uidl_match++;
                continue;
            }
            /* mismatch - can't trust the sizes */
            break;
        }

        if (pop3_map[i].size != imap_map[i].psize ||
            mstorage->skip_size_check)
            break;
        if (i+1 < count && pop3_map[i].size == pop3_map[i+1].size) {
            /* two messages with same size, don't trust them */
            break;
        }

        size_match++;
        pop3_map[i].imap_uid = imap_map[i].uid;
        imap_map[i].pop3_uidl = pop3_map[i].pop3_uidl;
        imap_map[i].pop3_seq = pop3_map[i].pop3_seq;
    }
    mbox->first_unfound_idx = i;
    if (box->storage->user->mail_debug) {
        i_debug("pop3_migration: cached uidls=%u, size matches=%u, total=%u",
            uidl_match, size_match, count);
    }
    return i == count && imap_count == pop3_count;
}

static int
pop3_uidl_assign_by_hdr_hash(struct mailbox *box, struct mailbox *pop3_box)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(box->storage);
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct pop3_uidl_map *pop3_map;
    struct imap_msg_map *imap_map;
    unsigned int pop3_idx, imap_idx, pop3_count, imap_count;
    unsigned int first_seq, missing_uids_count;
    uint32_t first_missing_idx = 0, first_missing_seq = (uint32_t)-1;
    int ret;

    first_seq = mbox->first_unfound_idx+1;
    if (pop3_map_read_hdr_hashes(box->storage, pop3_box, first_seq) < 0 ||
        imap_map_read_hdr_hashes(box) < 0)
        return -1;

    array_sort(&mstorage->pop3_uidl_map, pop3_uidl_map_hdr_cmp);
    array_sort(&mbox->imap_msg_map, imap_msg_map_hdr_cmp);

    pop3_map = array_get_modifiable(&mstorage->pop3_uidl_map, &pop3_count);
    imap_map = array_get_modifiable(&mbox->imap_msg_map, &imap_count);

    pop3_idx = imap_idx = 0;
    while (pop3_idx < pop3_count && imap_idx < imap_count) {
        if (!pop3_map[pop3_idx].common.hdr_sha1_set ||
            pop3_map[pop3_idx].imap_uid != 0) {
            pop3_idx++;
            continue;
        }
        if (!imap_map[imap_idx].common.hdr_sha1_set ||
            imap_map[imap_idx].pop3_uidl != NULL) {
            imap_idx++;
            continue;
        }
        ret = memcmp(pop3_map[pop3_idx].common.hdr_sha1,
                 imap_map[imap_idx].common.hdr_sha1,
                 sizeof(pop3_map[pop3_idx].common.hdr_sha1));
        if (ret < 0)
            pop3_idx++;
        else if (ret > 0)
            imap_idx++;
        else {
            pop3_map[pop3_idx].imap_uid = imap_map[imap_idx].uid;
            imap_map[imap_idx].pop3_uidl =
                pop3_map[pop3_idx].pop3_uidl;
            imap_map[imap_idx].pop3_seq =
                pop3_map[pop3_idx].pop3_seq;
        }
    }
    missing_uids_count = 0;
    for (pop3_idx = 0; pop3_idx < pop3_count; pop3_idx++) {
        if (pop3_map[pop3_idx].imap_uid != 0) {
            /* matched */
        } else if (!pop3_map[pop3_idx].common.hdr_sha1_set) {
            /* we treated this mail as expunged - ignore */
        } else {
            uint32_t seq = pop3_map[pop3_idx].pop3_seq;
            if (first_missing_seq > seq) {
                first_missing_seq = seq;
                first_missing_idx = pop3_idx;
            }
            missing_uids_count++;
        }
    }
    if (missing_uids_count > 0 && !mstorage->all_mailboxes) {
        string_t *str = t_str_new(128);
        bool all_imap_mails_found = FALSE;

        str_printfa(str, "pop3_migration: %u POP3 messages have no "
                "matching IMAP messages (first POP3 msg %u UIDL %s)",
                missing_uids_count, first_missing_seq,
                pop3_map[first_missing_idx].pop3_uidl);
        if (imap_count + missing_uids_count == pop3_count) {
            str_append(str, " - all IMAP messages were found "
                "(POP3 contains more than IMAP INBOX - you may want to set pop3_migration_all_mailboxes=yes)");
            all_imap_mails_found = TRUE;
        }
        if (all_imap_mails_found && mstorage->ignore_extra_uidls) {
            /* pop3 had more mails than imap. maybe it was just
               that a new mail was just delivered. */
        } else if (!mstorage->ignore_missing_uidls) {
            str_append(str, " - set pop3_migration_ignore_missing_uidls=yes");
            if (all_imap_mails_found)
                str_append(str, " or pop3_migration_ignore_extra_uidls=yes");
            i_error("%s to continue anyway", str_c(str));
            return -1;
        }
        i_warning("%s", str_c(str));
    } else if (box->storage->user->mail_debug) {
        i_debug("pop3_migration: %u mails matched by headers", pop3_count);
    }
    array_sort(&mstorage->pop3_uidl_map, pop3_uidl_map_pop3_seq_cmp);
    array_sort(&mbox->imap_msg_map, imap_msg_map_uid_cmp);
    return 0;
}

static void imap_uidls_add_to_cache(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct mailbox_transaction_context *t;
    struct mail *mail;
    struct index_mail *imail;
    struct imap_msg_map *imap_map;
    unsigned int i, count;
    unsigned int field_idx;

    t = mailbox_transaction_begin(box, 0, __func__);
    mail = mail_alloc(t, 0, NULL);
    imail = INDEX_MAIL(mail);
    field_idx = imail->ibox->cache_fields[MAIL_CACHE_POP3_UIDL].idx;

    imap_map = array_get_modifiable(&mbox->imap_msg_map, &count);
    for (i = 0; i < count; i++) {
        if (imap_map[i].pop3_uidl == NULL)
            continue;

        if (!mail_set_uid(mail, imap_map[i].uid))
            i_unreached();
        if (mail_cache_field_can_add(t->cache_trans, mail->seq, field_idx)) {
            index_mail_cache_add_idx(imail, field_idx,
                imap_map[i].pop3_uidl, strlen(imap_map[i].pop3_uidl)+1);
        }
    }
    mail_free(&mail);
    (void)mailbox_transaction_commit(&t);
}

static int pop3_migration_uidl_sync(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(box->storage);
    struct mailbox *pop3_box;

    pop3_box = pop3_mailbox_alloc(box->storage);
    /* the POP3 server isn't connected to yet. handle all IMAP traffic
       first before connecting, so POP3 server won't disconnect us due to
       idling. */
    if (imap_map_read(box) < 0 ||
        pop3_map_read(box->storage, pop3_box) < 0) {
        mailbox_free(&pop3_box);
        return -1;
    }

    pop3_uidl_assign_cached(box);

    array_sort(&mstorage->pop3_uidl_map, pop3_uidl_map_pop3_seq_cmp);
    array_sort(&mbox->imap_msg_map, imap_msg_map_uid_cmp);

    if (!pop3_uidl_assign_by_size(box)) {
        /* everything wasn't assigned, figure out the rest with
           header hashes */
        if (pop3_uidl_assign_by_hdr_hash(box, pop3_box) < 0) {
            mailbox_free(&pop3_box);
            return -1;
        }
    }

    if (!mstorage->skip_uidl_cache)
        imap_uidls_add_to_cache(box);

    mbox->uidl_synced = TRUE;
    mailbox_free(&pop3_box);
    return 0;
}

static int pop3_migration_uidl_sync_if_needed(struct mailbox *box)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(box);

    if (mbox->uidl_synced)
        return 0;

    if (mbox->uidl_sync_failed ||
        pop3_migration_uidl_sync(box) < 0) {
        mbox->uidl_sync_failed = TRUE;
        mail_storage_set_error(box->storage, MAIL_ERROR_TEMP,
                       "POP3 UIDLs couldn't be synced");
        return -1;
    }
    return 0;
}

static int
pop3_migration_get_special(struct mail *_mail, enum mail_fetch_field field,
               const char **value_r)
{
    struct mail_private *mail = (struct mail_private *)_mail;
    union mail_module_context *mmail = POP3_MIGRATION_MAIL_CONTEXT(mail);
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(_mail->box);
    struct imap_msg_map map_key, *map;

    if (field == MAIL_FETCH_UIDL_BACKEND ||
        field == MAIL_FETCH_POP3_ORDER) {
        if (pop3_migration_uidl_sync_if_needed(_mail->box) < 0)
            return -1;

        i_zero(&map_key);
        map_key.uid = _mail->uid;
        map = array_bsearch(&mbox->imap_msg_map, &map_key,
                    imap_msg_map_uid_cmp);
        if (map != NULL && map->pop3_uidl != NULL) {
            if (field == MAIL_FETCH_UIDL_BACKEND)
                *value_r = map->pop3_uidl;
            else
                *value_r = t_strdup_printf("%u", map->pop3_seq);
            return 0;
        }
        /* not found from POP3 server, fallback to default */
    }
    return mmail->super.get_special(_mail, field, value_r);
}

static void pop3_migration_mail_allocated(struct mail *_mail)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT(_mail->box->storage);
    struct mail_private *mail = (struct mail_private *)_mail;
    struct mail_vfuncs *v = mail->vlast;
    union mail_module_context *mmail;
    struct mail_namespace *ns;

    if (mstorage == NULL ||
        (!mstorage->all_mailboxes && !_mail->box->inbox_user)) {
        /* assigns UIDLs only for INBOX */
        return;
    }

    ns = mail_namespace_find(_mail->box->storage->user->namespaces,
                 mstorage->pop3_box_vname);
    if (ns == mailbox_get_namespace(_mail->box)) {
        /* we're accessing the pop3-migration namespace itself */
        return;
    }

    mmail = p_new(mail->pool, union mail_module_context, 1);
    mmail->super = *v;
    mail->vlast = &mmail->super;

    v->get_special = pop3_migration_get_special;
    MODULE_CONTEXT_SET_SELF(mail, pop3_migration_mail_module, mmail);
}

static struct mail_search_context *
pop3_migration_mailbox_search_init(struct mailbox_transaction_context *t,
                   struct mail_search_args *args,
                   const enum mail_sort_type *sort_program,
                   enum mail_fetch_field wanted_fields,
                   struct mailbox_header_lookup_ctx *wanted_headers)
{
    struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT_REQUIRE(t->box);
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(t->box->storage);

    if ((wanted_fields & (MAIL_FETCH_UIDL_BACKEND |
                  MAIL_FETCH_POP3_ORDER)) != 0 &&
        (mstorage->all_mailboxes || t->box->inbox_user)) {
        /* Start POP3 UIDL syncing before the search, so we'll do it
           before we start sending any FETCH BODY[]s to IMAP. It
           shouldn't matter much, except this works around a bug in
           Yahoo IMAP where it sometimes breaks its state when doing
           a FETCH BODY[] followed by FETCH BODY[HEADER].. */
        (void)pop3_migration_uidl_sync_if_needed(t->box);
    }

    return mbox->module_ctx.super.search_init(t, args, sort_program,
                          wanted_fields, wanted_headers);
}

static void pop3_migration_mailbox_allocated(struct mailbox *box)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT(box->storage);
    struct mailbox_vfuncs *v = box->vlast;
    struct pop3_migration_mailbox *mbox;

    if (mstorage == NULL)
        return;

    mbox = p_new(box->pool, struct pop3_migration_mailbox, 1);
    mbox->module_ctx.super = *v;
    box->vlast = &mbox->module_ctx.super;

    v->search_init = pop3_migration_mailbox_search_init;

    MODULE_CONTEXT_SET(box, pop3_migration_storage_module, mbox);
}

static void pop3_migration_mail_storage_destroy(struct mail_storage *storage)
{
    struct pop3_migration_mail_storage *mstorage =
        POP3_MIGRATION_CONTEXT_REQUIRE(storage);

    if (array_is_created(&mstorage->pop3_uidl_map))
        array_free(&mstorage->pop3_uidl_map);

    mstorage->module_ctx.super.destroy(storage);
}

static void pop3_migration_mail_storage_created(struct mail_storage *storage)
{
    struct pop3_migration_mail_storage *mstorage;
    struct mail_storage_vfuncs *v = storage->vlast;
    const char *pop3_box_vname;

    pop3_box_vname = mail_user_plugin_getenv(storage->user,
                         "pop3_migration_mailbox");
    if (pop3_box_vname == NULL) {
        if (storage->user->mail_debug)
            i_debug("pop3_migration: No pop3_migration_mailbox setting - disabled");
        return;
    }

    mstorage = p_new(storage->pool, struct pop3_migration_mail_storage, 1);
    mstorage->module_ctx.super = *v;
    storage->vlast = &mstorage->module_ctx.super;
    v->destroy = pop3_migration_mail_storage_destroy;

    mstorage->pop3_box_vname = p_strdup(storage->pool, pop3_box_vname);
    mstorage->all_mailboxes =
        mail_user_plugin_getenv_bool(storage->user,
                    "pop3_migration_all_mailboxes");
    mstorage->ignore_missing_uidls =
        mail_user_plugin_getenv_bool(storage->user,
            "pop3_migration_ignore_missing_uidls");
    mstorage->ignore_extra_uidls =
        mail_user_plugin_getenv_bool(storage->user,
            "pop3_migration_ignore_extra_uidls");
    mstorage->skip_size_check =
        mail_user_plugin_getenv_bool(storage->user,
            "pop3_migration_skip_size_check");
    mstorage->skip_uidl_cache =
        mail_user_plugin_getenv_bool(storage->user,
            "pop3_migration_skip_uidl_cache");

    MODULE_CONTEXT_SET(storage, pop3_migration_storage_module, mstorage);
}

static struct mail_storage_hooks pop3_migration_mail_storage_hooks = {
    .mail_allocated = pop3_migration_mail_allocated,
    .mailbox_allocated = pop3_migration_mailbox_allocated,
    .mail_storage_created = pop3_migration_mail_storage_created
};

void pop3_migration_plugin_init(struct module *module)
{
    mail_storage_hooks_add(module, &pop3_migration_mail_storage_hooks);
}

void pop3_migration_plugin_deinit(void)
{
    mail_storage_hooks_remove(&pop3_migration_mail_storage_hooks);
}