commit 8cdb18ca1829a0b7faa1c9e472604ed0e7e105ac Author: Christos Tsantilas Date: 2019-12-20 07:29:58 +0000 Fix FTP buffers handling (#521) Fix the parsing of the received listing from FTP services. Also relaxed size/filename grammar used for DOS listings: Tolerate multiple spaces between the size and the filename. This is a Measurement Factory project diff --git a/src/clients/FtpGateway.cc b/src/clients/FtpGateway.cc index 2e50ad9..5bac13b 100644 --- a/src/clients/FtpGateway.cc +++ b/src/clients/FtpGateway.cc @@ -539,8 +539,10 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) { ftpListParts *p = NULL; char *t = NULL; - const char *ct = NULL; - char *tokens[MAX_TOKENS]; + struct FtpLineToken { + char *token = NULL; ///< token image copied from the received line + size_t pos = 0; ///< token offset on the received line + } tokens[MAX_TOKENS]; int i; int n_tokens; static char tbuf[128]; @@ -581,7 +583,8 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) } for (t = strtok(xbuf, w_space); t && n_tokens < MAX_TOKENS; t = strtok(NULL, w_space)) { - tokens[n_tokens] = xstrdup(t); + tokens[n_tokens].token = xstrdup(t); + tokens[n_tokens].pos = t - xbuf; ++n_tokens; } @@ -589,10 +592,10 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) /* locate the Month field */ for (i = 3; i < n_tokens - 2; ++i) { - char *size = tokens[i - 1]; - char *month = tokens[i]; - char *day = tokens[i + 1]; - char *year = tokens[i + 2]; + const char *size = tokens[i - 1].token; + char *month = tokens[i].token; + char *day = tokens[i + 1].token; + char *year = tokens[i + 2].token; if (!is_month(month)) continue; @@ -606,23 +609,27 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) if (regexec(&scan_ftp_time, year, 0, NULL, 0) != 0) /* Yr | hh:mm */ continue; - snprintf(tbuf, 128, "%s %2s %5s", - month, day, year); + const char *copyFrom = buf + tokens[i].pos; - if (!strstr(buf, tbuf)) - snprintf(tbuf, 128, "%s %2s %-5s", - month, day, year); + // "MMM DD [ YYYY|hh:mm]" with at most two spaces between DD and YYYY + int dateSize = snprintf(tbuf, sizeof(tbuf), "%s %2s %5s", month, day, year); + bool isTypeA = (dateSize == 12) && (strncmp(copyFrom, tbuf, dateSize) == 0); - char const *copyFrom = NULL; + // "MMM DD [YYYY|hh:mm]" with one space between DD and YYYY + dateSize = snprintf(tbuf, sizeof(tbuf), "%s %2s %-5s", month, day, year); + bool isTypeB = (dateSize == 12 || dateSize == 11) && (strncmp(copyFrom, tbuf, dateSize) == 0); - if ((copyFrom = strstr(buf, tbuf))) { - p->type = *tokens[0]; + // TODO: replace isTypeA and isTypeB with a regex. + if (isTypeA || isTypeB) { + p->type = *tokens[0].token; p->size = strtoll(size, NULL, 10); + const int finalDateSize = snprintf(tbuf, sizeof(tbuf), "%s %2s %5s", month, day, year); + assert(finalDateSize >= 0); p->date = xstrdup(tbuf); + // point after tokens[i+2] : + copyFrom = buf + tokens[i + 2].pos + strlen(tokens[i + 2].token); if (flags.skip_whitespace) { - copyFrom += strlen(tbuf); - while (strchr(w_space, *copyFrom)) ++copyFrom; } else { @@ -634,7 +641,6 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) * Assuming a single space between date and filename * suggested by: Nathan.Bailey@cc.monash.edu.au and * Mike Battersby */ - copyFrom += strlen(tbuf); if (strchr(w_space, *copyFrom)) ++copyFrom; } @@ -654,45 +660,36 @@ ftpListParseParts(const char *buf, struct Ftp::GatewayFlags flags) /* try it as a DOS listing, 04-05-70 09:33PM ... */ if (n_tokens > 3 && - regexec(&scan_ftp_dosdate, tokens[0], 0, NULL, 0) == 0 && - regexec(&scan_ftp_dostime, tokens[1], 0, NULL, 0) == 0) { - if (!strcasecmp(tokens[2], "")) { + regexec(&scan_ftp_dosdate, tokens[0].token, 0, NULL, 0) == 0 && + regexec(&scan_ftp_dostime, tokens[1].token, 0, NULL, 0) == 0) { + if (!strcasecmp(tokens[2].token, "")) { p->type = 'd'; } else { p->type = '-'; - p->size = strtoll(tokens[2], NULL, 10); + p->size = strtoll(tokens[2].token, NULL, 10); } - snprintf(tbuf, 128, "%s %s", tokens[0], tokens[1]); + snprintf(tbuf, sizeof(tbuf), "%s %s", tokens[0].token, tokens[1].token); p->date = xstrdup(tbuf); if (p->type == 'd') { - /* Directory.. name begins with first printable after */ - ct = strstr(buf, tokens[2]); - ct += strlen(tokens[2]); - - while (xisspace(*ct)) - ++ct; - - if (!*ct) - ct = NULL; + // Directory.. name begins with first printable after + // Because of the "n_tokens > 3", the next printable after + // is stored at token[3]. No need for more checks here. } else { - /* A file. Name begins after size, with a space in between */ - snprintf(tbuf, 128, " %s %s", tokens[2], tokens[3]); - ct = strstr(buf, tbuf); - - if (ct) { - ct += strlen(tokens[2]) + 2; - } + // A file. Name begins after size, with a space in between. + // Also a space should exist before size. + // But there is not needed to be very strict with spaces. + // The name is stored at token[3], take it from here. } - p->name = xstrdup(ct ? ct : tokens[3]); + p->name = xstrdup(tokens[3].token); goto found; } /* Try EPLF format; carson@lehman.com */ if (buf[0] == '+') { - ct = buf + 1; + const char *ct = buf + 1; p->type = 0; while (ct && *ct) { @@ -763,7 +760,7 @@ blank: found: for (i = 0; i < n_tokens; ++i) - xfree(tokens[i]); + xfree(tokens[i].token); if (!p->name) ftpListPartsFree(&p); /* cleanup */