isync

mailbox synchronization program
git clone https://git.code.sf.net/p/isync/isync
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commit 8d9c68f73a43acce083134c22eaeae2dedc8ecbf
parent c5e967f94d94c151b9f5ed7900bf09a1e4ff396d
Author: Oswald Buddenhagen <ossi@users.sf.net>
Date:   Thu, 25 Nov 2021 14:02:10 +0100

optimize string operations in IMAP parser

the string length is knowable in advance everywhere, so we can use that
for strdups and short-circuiting comparisons.

Diffstat:
Msrc/common.h | 1+
Msrc/drv_imap.c | 141++++++++++++++++++++++++++++++++++++++++++-------------------------------------
Msrc/util.c | 24++++++++++++++++++++----
3 files changed, 96 insertions(+), 70 deletions(-)

diff --git a/src/common.h b/src/common.h @@ -192,6 +192,7 @@ size_t strnlen( const char *str, size_t maxlen ); int starts_with( const char *str, int strl, const char *cmp, uint cmpl ); int starts_with_upper( const char *str, int strl, const char *cmp, uint cmpl ); int equals( const char *str, int strl, const char *cmp, uint cmpl ); +int equals_upper( const char *str, int strl, const char *cmp, uint cmpl ); #ifndef HAVE_TIMEGM time_t timegm( struct tm *tm ); diff --git a/src/drv_imap.c b/src/drv_imap.c @@ -240,20 +240,23 @@ enum CAPABILITY { COMPRESS_DEFLATE }; -static const char *cap_list[] = { - "LOGINDISABLED", +static const struct { + const char *str; + uint len; +} cap_list[] = { + { "LOGINDISABLED", 13 }, #ifdef HAVE_LIBSASL - "SASL-IR", + { "SASL-IR", 7 }, #endif #ifdef HAVE_LIBSSL - "STARTTLS", + { "STARTTLS", 8 }, #endif - "UIDPLUS", - "LITERAL+", - "LITERAL-", - "MOVE", - "NAMESPACE", - "COMPRESS=DEFLATE" + { "UIDPLUS", 7 }, + { "LITERAL+", 8 }, + { "LITERAL-", 8 }, + { "MOVE", 4 }, + { "NAMESPACE", 9 }, + { "COMPRESS=DEFLATE", 16 }, }; #define RESP_OK 0 @@ -719,7 +722,7 @@ imap_strchr( const char *s, char tc ) } static char * -next_arg( char **ps ) +next_arg( char **ps, uint *len ) { char *ret, *s, *d; char c; @@ -747,19 +750,26 @@ next_arg( char **ps ) *d++ = c; } *d = 0; + *len = (uint)(d - ret); + if (!*s) + s = NULL; } else { ret = s; while ((c = *s)) { if (isspace( (uchar)c )) { + *len = (uint)(s - ret); *s++ = 0; - break; + if (!*s) + s = NULL; + goto out; } s++; } - } - if (!*s) + *len = (uint)(s - ret); s = NULL; + } + out: *ps = s; return ret; } @@ -1076,7 +1086,7 @@ parse_fetched_flags( list_t *list, uchar *flags, uchar *status ) } if (list->val[0] != '\\' && list->val[0] != '$') continue; - if (!strcmp( "\\Recent", list->val )) { + if (equals( list->val, list->len, "\\Recent", 7 )) { *status |= M_RECENT; goto flagok; } @@ -1160,13 +1170,14 @@ parse_fetch_rsp( imap_store_t *ctx, list_t *list ) return LIST_BAD; } const char *name = tmp->val; + uint namel = tmp->len; tmp = tmp->next; - if (!strcmp( "UID", name )) { + if (equals( name, namel, "UID", 3 )) { if (!is_atom( tmp ) || (uid = strtoul( tmp->val, &ep, 10 ), *ep)) { error( "IMAP error: unable to parse UID\n" ); return LIST_BAD; } - } else if (!strcmp( "FLAGS", name )) { + } else if (equals( name, namel, "FLAGS", 5 )) { if (!is_list( tmp )) { error( "IMAP error: unable to parse FLAGS\n" ); return LIST_BAD; @@ -1174,7 +1185,7 @@ parse_fetch_rsp( imap_store_t *ctx, list_t *list ) if (!parse_fetched_flags( tmp->child, &mask, &status )) return LIST_BAD; status |= M_FLAGS; - } else if (!strcmp( "INTERNALDATE", name )) { + } else if (equals( name, namel, "INTERNALDATE", 12 )) { if (!is_atom( tmp )) { error( "IMAP error: unable to parse INTERNALDATE\n" ); return LIST_BAD; @@ -1184,27 +1195,27 @@ parse_fetch_rsp( imap_store_t *ctx, list_t *list ) return LIST_BAD; } status |= M_DATE; - } else if (!strcmp( "RFC822.SIZE", name )) { + } else if (equals( name, namel, "RFC822.SIZE", 11 )) { if (!is_atom( tmp ) || (size = strtoul( tmp->val, &ep, 10 ), *ep)) { error( "IMAP error: unable to parse RFC822.SIZE\n" ); return LIST_BAD; } status |= M_SIZE; - } else if (!strcmp( "BODY[]", name ) || !strcmp( "BODY[HEADER]", name )) { + } else if (equals( name, namel, "BODY[]", 6 ) || equals( name, namel, "BODY[HEADER]", 12 )) { if (!is_atom( tmp )) { error( "IMAP error: unable to parse BODY[]\n" ); return LIST_BAD; } body = tmp; status |= M_BODY; - } else if (!strcmp( "BODY[HEADER.FIELDS", name )) { + } else if (equals( name, namel, "BODY[HEADER.FIELDS", 18 )) { if (!is_list( tmp )) { bfail: error( "IMAP error: unable to parse BODY[HEADER.FIELDS ...]\n" ); return LIST_BAD; } tmp = tmp->next; - if (!is_atom( tmp ) || strcmp( tmp->val, "]" )) + if (!is_atom( tmp ) || !equals( tmp->val, tmp->len, "]", 1 )) goto bfail; tmp = tmp->next; if (!is_atom( tmp )) @@ -1265,52 +1276,53 @@ static void parse_capability( imap_store_t *ctx, char *cmd ) { char *arg; - uint i; + uint i, argl; free_string_list( ctx->auth_mechs ); ctx->auth_mechs = NULL; ctx->caps = 0x80000000; - while ((arg = next_arg( &cmd ))) { - if (starts_with( arg, -1, "AUTH=", 5 )) { - add_string_list( &ctx->auth_mechs, arg + 5 ); + while ((arg = next_arg( &cmd, &argl ))) { + if (starts_with( arg, argl, "AUTH=", 5 )) { + add_string_list_n( &ctx->auth_mechs, arg + 5, argl - 5 ); } else { for (i = 0; i < as(cap_list); i++) - if (!strcmp( cap_list[i], arg )) + if (equals( arg, argl, cap_list[i].str, cap_list[i].len )) ctx->caps |= 1 << i; } } ctx->caps &= ~ctx->conf->server->cap_mask; if (!CAP(NOLOGIN)) - add_string_list( &ctx->auth_mechs, "LOGIN" ); + add_string_list_n( &ctx->auth_mechs, "LOGIN", 5 ); } static int parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s ) { char *arg, *earg, *p; + uint argl; if (!s || *s != '[') return RESP_OK; /* no response code */ s++; - if (!(arg = next_arg( &s ))) { + if (!(arg = next_arg( &s, &argl ))) { error( "IMAP error: malformed response code\n" ); return RESP_CANCEL; } - if (!strcmp( "UIDVALIDITY", arg )) { - if (!(arg = next_arg( &s )) || + if (equals( arg, argl, "UIDVALIDITY", 11 )) { + if (!(arg = next_arg( &s, &argl )) || (ctx->uidvalidity = strtoul( arg, &earg, 10 ), *earg != ']')) { error( "IMAP error: malformed UIDVALIDITY status\n" ); return RESP_CANCEL; } - } else if (!strcmp( "UIDNEXT", arg )) { - if (!(arg = next_arg( &s )) || + } else if (equals( arg, argl, "UIDNEXT", 7 )) { + if (!(arg = next_arg( &s, &argl )) || (ctx->uidnext = strtoul( arg, &earg, 10 ), *earg != ']')) { error( "IMAP error: malformed UIDNEXT status\n" ); return RESP_CANCEL; } - } else if (!strcmp( "CAPABILITY", arg )) { + } else if (equals( arg, argl, "CAPABILITY", 10 )) { if (!s || !(p = strchr( s, ']' ))) { error( "IMAP error: malformed CAPABILITY status\n" ); return RESP_CANCEL; @@ -1319,7 +1331,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s ) parse_capability( ctx, s ); if (strstr( p + 1, "mac.com IMAP4 service (Oracle Communications Messaging Server" )) ctx->capability_hack = 1; - } else if (!strcmp( "ALERT]", arg )) { + } else if (equals( arg, argl, "ALERT]", 6 )) { /* RFC2060 says that these messages MUST be displayed * to the user */ @@ -1329,7 +1341,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s ) } for (; isspace( (uchar)*s ); s++); error( "*** IMAP ALERT *** %s\n", s ); - } else if (!strcmp( "APPENDUID", arg )) { + } else if (equals( arg, argl, "APPENDUID", 9 )) { // The checks ensure that: // - cmd => this is the final tagged response of a command, at which // point cmd was already removed from ctx->in_progress, so param.uid @@ -1341,15 +1353,15 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s ) error( "IMAP error: unexpected APPENDUID status\n" ); return RESP_CANCEL; } - if (!(arg = next_arg( &s )) || + if (!(arg = next_arg( &s, &argl )) || (ctx->uidvalidity = strtoul( arg, &earg, 10 ), *earg) || - !(arg = next_arg( &s )) || + !(arg = next_arg( &s, &argl )) || (cmd->param.uid = strtoul( arg, &earg, 10 ), *earg != ']')) { error( "IMAP error: malformed APPENDUID status\n" ); return RESP_CANCEL; } - } else if (!strcmp( "PERMANENTFLAGS", arg )) { + } else if (equals( arg, argl, "PERMANENTFLAGS", 14 )) { parse_list_init( &ctx->parse_list_sts ); if (parse_imap_list( NULL, &s, &ctx->parse_list_sts ) != LIST_OK || *s != ']') { error( "IMAP error: malformed PERMANENTFLAGS status\n" ); @@ -1362,7 +1374,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s ) ret = RESP_CANCEL; break; } - if (!strcmp( tmp->val, "\\*" ) || !strcmp( tmp->val, "$Forwarded" )) { + if (equals( tmp->val, tmp->len, "\\*", 2 ) || equals( tmp->val, tmp->len, "$Forwarded", 10 )) { ctx->has_forwarded = 1; break; } @@ -1385,7 +1397,7 @@ parse_list_rsp( imap_store_t *ctx, list_t *list ) if (!is_list( list )) return parse_list_perror( ctx ); for (lp = list->child; lp; lp = lp->next) - if (is_atom( lp ) && !strcasecmp( lp->val, "\\NoSelect" )) + if (is_atom( lp ) && equals_upper( lp->val, lp->len, "\\NOSELECT", 9 )) return parse_next_list( ctx, parse_namespace_rsp_p2 ); // (sic!) return parse_next_list( ctx, parse_list_rsp_p1 ); } @@ -1573,7 +1585,7 @@ imap_socket_read( void *aux ) imap_cmd_t *cmdp, **pcmdp; char *cmd, *arg, *arg1, *p; int resp, resp2, tag; - uint seq; + uint seq, argl, argl1; conn_iovec_t iov[2]; for (;;) { @@ -1599,19 +1611,17 @@ imap_socket_read( void *aux ) fflush( stdout ); } - arg = next_arg( &cmd ); - if (!arg) { + if (!(arg = next_arg( &cmd, &argl ))) { error( "IMAP error: empty response\n" ); break; } if (*arg == '*') { - arg = next_arg( &cmd ); - if (!arg) { + if (!(arg = next_arg( &cmd, &argl ))) { error( "IMAP error: malformed untagged response\n" ); break; } - if (ctx->greeting == GreetingPending && !strcmp( "PREAUTH", arg )) { + if (ctx->greeting == GreetingPending && equals( arg, argl, "PREAUTH", 7 )) { parse_response_code( ctx, NULL, cmd ); ctx->greeting = GreetingPreauth; dogreet: @@ -1619,13 +1629,13 @@ imap_socket_read( void *aux ) imap_open_store_greeted( ctx ); if (imap_deref( ctx )) return; - } else if (!strcmp( "OK", arg )) { + } else if (equals( arg, argl, "OK", 2 )) { parse_response_code( ctx, NULL, cmd ); if (ctx->greeting == GreetingPending) { ctx->greeting = GreetingOk; goto dogreet; } - } else if (!strcmp( "BYE", arg )) { + } else if (equals( arg, argl, "BYE", 3 )) { if (!ctx->expectBYE) { ctx->greeting = GreetingBad; error( "IMAP error: unexpected BYE response: %s\n", cmd ); @@ -1638,22 +1648,22 @@ imap_socket_read( void *aux ) } else if (ctx->greeting == GreetingPending) { error( "IMAP error: bogus greeting response %s\n", arg ); break; - } else if (!strcmp( "NO", arg )) { + } else if (equals( arg, argl, "NO", 2 )) { warn( "Warning from IMAP server: %s\n", cmd ); - } else if (!strcmp( "BAD", arg )) { + } else if (equals( arg, argl, "BAD", 3 )) { error( "Error from IMAP server: %s\n", cmd ); - } else if (!strcmp( "CAPABILITY", arg )) { + } else if (equals( arg, argl, "CAPABILITY", 10 )) { parse_capability( ctx, cmd ); - } else if (!strcmp( "LIST", arg ) || !strcmp( "LSUB", arg )) { + } else if (equals( arg, argl, "LIST", 4 ) || equals( arg, argl, "LSUB", 4 )) { resp = parse_list( ctx, cmd, parse_list_rsp, "LIST" ); goto listret; - } else if (!strcmp( "NAMESPACE", arg )) { + } else if (equals( arg, argl, "NAMESPACE", 9 )) { resp = parse_list( ctx, cmd, parse_namespace_rsp, "NAMESPACE" ); goto listret; - } else if ((arg1 = next_arg( &cmd ))) { - if (!strcmp( "EXISTS", arg1 )) { + } else if ((arg1 = next_arg( &cmd, &argl1 ))) { + if (equals( arg1, argl1, "EXISTS", 6 )) { ctx->total_msgs = atoi( arg ); - } else if (!strcmp( "EXPUNGE", arg1 )) { + } else if (equals( arg1, argl1, "EXPUNGE", 7 )) { if (!(seq = strtoul( arg, &arg1, 10 )) || *arg1) { badseq: error( "IMAP error: malformed sequence number '%s'\n", arg ); @@ -1661,9 +1671,9 @@ imap_socket_read( void *aux ) } record_expunge( ctx, seq ); ctx->total_msgs--; - } else if (!strcmp( "RECENT", arg1 )) { + } else if (equals( arg1, argl1, "RECENT", 6 )) { ctx->recent_msgs = atoi( arg ); - } else if (!strcmp( "FETCH", arg1 )) { + } else if (equals( arg1, argl1, "FETCH", 5 )) { if (!(seq = strtoul( arg, &arg1, 10 )) || *arg1) goto badseq; ctx->fetch_seq = seq; @@ -1722,17 +1732,16 @@ imap_socket_read( void *aux ) ctx->in_progress_append = pcmdp; if (!--ctx->num_in_progress) socket_expect_activity( &ctx->conn, 0 ); - arg = next_arg( &cmd ); - if (!arg) { + if (!(arg = next_arg( &cmd, &argl ))) { error( "IMAP error: malformed tagged response\n" ); break; } - if (!strcmp( "OK", arg )) { + if (equals( arg, argl, "OK", 2 )) { if (cmdp->param.to_trash) ctx->trashnc = TrashKnown; /* Can't get NO [TRYCREATE] any more. */ resp = RESP_OK; } else { - if (!strcmp( "NO", arg )) { + if (equals( arg, argl, "NO", 2 )) { if (cmdp->param.create && cmd && starts_with( cmd, -1, "[TRYCREATE]", 11 )) { /* APPEND or UID COPY */ imap_cmd_trycreate_t *cmd2 = (imap_cmd_trycreate_t *)new_imap_cmd( sizeof(*cmd2) ); @@ -1746,7 +1755,7 @@ imap_socket_read( void *aux ) resp = RESP_NO; if (cmdp->param.failok) // SELECT goto doresp; - } else /*if (!strcmp( "BAD", arg ))*/ { + } else /*if (equals( arg, argl, "BAD", 3 ))*/ { if (cmdp->param.failok == 2 && cmd && starts_with_upper( cmd, -1, "[TOOBIG]", 8 )) { // APPEND resp = RESP_NO; // Fall through - we still complain @@ -2416,7 +2425,7 @@ imap_open_store_authenticate2( imap_store_t *ctx ) info( "Logging in...\n" ); for (mech = srvc->auth_mechs; mech; mech = mech->next) { - int any = !strcmp( mech->string, "*" ); + int any = equals( mech->string, -1, "*", 1 ); for (cmech = ctx->auth_mechs; cmech; cmech = cmech->next) { if (any || !strcasecmp( mech->string, cmech->string )) { if (!strcasecmp( cmech->string, "LOGIN" )) { @@ -3616,7 +3625,7 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep ) arg = cfg->val; do { for (u = 0; u < as(cap_list); u++) { - if (!strcasecmp( cap_list[u], arg )) { + if (equals_upper( arg, -1, cap_list[u].str, cap_list[u].len )) { server->cap_mask |= 1 << u; goto gotcap; } diff --git a/src/util.c b/src/util.c @@ -292,6 +292,15 @@ starts_with( const char *str, int strl, const char *cmp, uint cmpl ) return ((uint)strl >= cmpl) && !memcmp( str, cmp, cmpl ); } +static int +equals_upper_impl( const char *str, const char *cmp, uint cmpl ) +{ + for (uint i = 0; i < cmpl; i++) + if (toupper( str[i] ) != cmp[i]) + return 0; + return 1; +} + int starts_with_upper( const char *str, int strl, const char *cmp, uint cmpl ) { @@ -299,10 +308,7 @@ starts_with_upper( const char *str, int strl, const char *cmp, uint cmpl ) strl = strnlen( str, cmpl + 1 ); if ((uint)strl < cmpl) return 0; - for (uint i = 0; i < cmpl; i++) - if (toupper( str[i] ) != cmp[i]) - return 0; - return 1; + return equals_upper_impl( str, cmp, cmpl ); } int @@ -313,6 +319,16 @@ equals( const char *str, int strl, const char *cmp, uint cmpl ) return ((uint)strl == cmpl) && !memcmp( str, cmp, cmpl ); } +int +equals_upper( const char *str, int strl, const char *cmp, uint cmpl ) +{ + if (strl < 0) + strl = strnlen( str, cmpl + 1 ); + if ((uint)strl != cmpl) + return 0; + return equals_upper_impl( str, cmp, cmpl ); +} + #ifndef HAVE_TIMEGM /* Converts struct tm to time_t, assuming the data in tm is UTC rather